Wildlife Resource Trends

in the United States

Wildlife Resource Trends

in the United States

CURTIS H. FLATHER, STEPHEN J. BRADY, AND MICHAEL S. KNOWLES

U.S. DEPARTMENT OF AGRICULTURE FOREST SERVICE

A Technical Document Supporting the

2000 USDA Forest Service RPA Assessment

A Technical Document Supporting the

2000 USDA Forest Service RPA Assessment
Abstract

Flather, Curtis H.; Brady, Stephen J.; Knowles, Michael S. 1999. Wildlife resource trends in the United

States: A technical document supporting the 2000 RPA Assessment. Gen. Tech. Rep. RMRSGTR-33. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research

Station. 79 p.

This report documents trends in wildlife resources for the nation as required by the Renewable

Resources Planning Act (RPA) of 1974. The report focuses on recent historical trends in wildlife as

one indicator of ecosystem health across the United States and updates wildlife trends presented in

previous RPA Assessments. The report also shows short- and long-term projections of some wildlife

for documenting expected trajectories of resource change. National trends in four attributes of wildlife

resources, including habitat, population, harvest, and users, set the context within which regionspecific trends are presented. The data for this analysis came largely from information that currently

exists within Forest Service and cooperating state and federal agency inventories. The report

concludes with a synthesis of these trends as they relate to the concept of resource health. We

highlight those trends that appear to indicate favorable, uncertain, or degraded resource conditions

in an attempt to identify resource situations that warrant policy and management attention.

Keywords: wildlife resources, resource planning, national assessment, trends, wildlife populations,

wildlife habitats, wildlife harvests, recreation participation, bird diversity, threatened and endangered

species

The Authors

Curtis H. Flather is a research wildlife biologist at the Rocky Mountain Research Station in Fort Collins,

CO.

Stephen J. Brady is a wildlife biologist with the Natural Resources Conservation Service in Fort Collins,

CO.

Michael S. Knowles is an information systems analyst with the Management Assistance Company of

America at the Rocky Mountain Research Station in Fort Collins, CO.

You may order additional copies of this publication by sending your

mailing information in label form through one of the following media.

Please send the publication title and number.

Telephone (970) 498-1719

E-mail rschneider/rmrs@fs.fed.us

FAX (970) 498-1660

Mailing Address Publications Distribution

Rocky Mountain Research Station

3825 E. Mulberry Street

Fort Collins, CO 80524-8597

Cover photo of mule deer by Lane Eskew.
Contents

Introduction ................................................................................................... 1

Habitat Trends ............................................................................................... 3

General Land Use and Land Cover Trends ............................................... 3

Forest Habitats ........................................................................................... 5

Rangeland Habitats .................................................................................... 9

Agricultural Habitats ................................................................................... 13

Wetland Habitats ........................................................................................ 17

Implications of Habitat Trends to Wildlife ................................................... 19

Population and Harvest Trends ................................................................... 20

Big Game Species ...................................................................................... 21

Big game populations ............................................................................. 21

Big game harvests.................................................................................. 23

Small Game Species .................................................................................. 24

Small game populations ......................................................................... 25

Small game harvests .............................................................................. 29

Migratory Game Bird Species..................................................................... 30

Duck populations .................................................................................... 31

Duck harvests......................................................................................... 32

Goose and swan populations ................................................................. 33

Goose and swan harvests ...................................................................... 34

Dove and woodcock populations ........................................................... 35

Dove and woodcock harvests ................................................................ 37

Furbearer Species ...................................................................................... 38

Furbearer populations ............................................................................ 39

Fur harvest and price ............................................................................. 39

Nongame Species ...................................................................................... 43

Breeding bird populations ...................................................................... 43

Bird diversity and land use ..................................................................... 47

Amphibian populations ........................................................................... 51

Imperiled Species ....................................................................................... 54

Recent trends in species listings ............................................................ 54

Geographic patterns in species endangerment ..................................... 56

Projections of endangerment hotspots................................................... 58

Wildlife resource trends in the United States:

A technical document supporting the

2000 RPA Assessment

Curtis H. Flather, Stephen J. Brady, and Michael S. Knowles
Trends in Wildlife Use .................................................................................. 58

Hunting ....................................................................................................... 60

Nonconsumptive Wildlife Recreation .......................................................... 63

Trapping...................................................................................................... 63

Wildlife-Associated Recreation on National Forest System Lands ............ 64

Conclusions................................................................................................... 65

Acknowledgments ........................................................................................ 70

Literature Cited ............................................................................................. 70

Appendix A: Scientific Names ..................................................................... 76

Appendix B: Land Use and Land Cover Changes ..................................... 77
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999 1

Wildlife Resource Trends in the United States Flather, Brady, and Knowles

Introduction

Over the last 60 years of “modern” wildlife management in the United States, researchers have learned much

about how animals affect the structure and function of

ecosystems (see Pimentel and others 1997). Animals pollinate, help germinate, and disperse many plant species;

play important roles in nutrient flux and cycling; and help

break down pollutants and organic wastes. They also

provide recreational, commercial, and subsistence needs;

contribute to spiritual and intellectual stimulation; and

maintain biological diversity through interactions with

their habitat (e.g., herbivory) and among species (e.g.,

predation). Despite a widespread awareness of wildlife’s

role in ecosystems, the magnitude of the ecologic and

economic benefits attributable to wildlife is largely unrecognized by the public (Daily 1997).

Failure to recognize these benefits can lead to economic

development that degrades ecosystems. Such development, in conjunction with increasing human populations

and land use intensification, can stress ecosystems to a

point where their ability to provide the aforementioned

benefits is compromised (Rapport and others 1985;

Pimentel and others 1997). Concern that the human enterprise may jeopardize the viability of ecosystems (Holdgate

1994; Vitousek and others 1997) is at the crux of a natural

resource management shift that is now focusing on longterm sustainability of ecosystems (Lubchenco and others

1991; Christensen and others 1996).

Sustainability has been defined as “... the ability to

maintain something undiminished over some time period” (Lélé and Norgaard 1996:355). Applied to natural

resources, this definition implies that: (1) management

will not degrade those systems being utilized (Lubchenco

and others 1991), and (2) the current generation of humans will leave an equitable share of resources for future

generations (Meyer and Helfman 1993). Although formal

consideration of sustainability as a framework to guide

natural resource management has received much discussion in the last decade, its roots actually extend back to

classical economic theories proposed during the latter

half of the 19th century (van den Bergh and van der

Straaten 1994). As reviewed by Goodland (1995), the

writings of T.R. Malthus and J.S. Mill during this time

period emphasized concerns about exponential human

population growth, a finite natural resource base, and the

need for environmental protection to preserve human

welfare. Natural resource management has had a similarly long history of advancing sustainability concepts:

Sustainable forest management dates to the mid-1800s,

maximum sustained yield was the accepted management

paradigm for fisheries by the 1950s, and wildlife managers used the concept of reproductive surplus to recommend sustainable harvest strategies in the 1940s (Hilborn

and others 1995). Given this history, it should not be

surprising to see elements of the sustainable development

philosophy incorporated into more recent legislation that

guides federal natural resource policy and management.

The Forest and Rangeland Renewable Resources Planning Act (RPA) of 1974, as amended by the National

Forest Management Act (NFMA) of 1976, is one example

of legislation that mandates elements consistent with a

sustainable resource management perspective.

Our ability to manage ecosystems in a sustainable

manner requires an analysis of the system’s performance

and health over broad spatial and temporal scales

(Constanza 1992, Holling and Meffe 1996). The RPA

directs the Forest Service to prepare such broad-scaled

evaluations in the form of periodic national assessments

of natural resources on the nation’s 1.6 billion acres of

forest and range lands. These assessments are to report on

(1) the current status and condition of resources based on

an analysis of recent historical trends and (2) the future

resource situation based on trend projections (Cortner

and Schweitzer 1981). Although these resource assessments were initially interpreted in the context of resource

supplies and public demands (Hoekstra and others 1979),

they now offer an opportunity to examine resource health

in the context of sustainability. Sustainability is a broad

concept that encompasses many aspects of human development, resource management, and ecological response.

Therefore, sustainability is difficult to monitor directly

without specificity. Assessments of sustainability have

been couched in the concept of indicators (Hammond and

others 1995), which ostensibly represent key measurable

attributes that reflect ecosystem properties that are too

difficult or costly to monitor directly (Noss 1990).

The primary objective of this report is to present recent

historical and expected trends in wildlife resources across

the United States as one set of ecosystem health indicators. Secondarily, this report also updates wildlife resource trends that have been presented as components of

previous RPA Assessments (see, Flather and Hoekstra

1989; USDA Forest Service 1981). For the purposes of this

report, wildlife are defined as free-ranging vertebrate and

invertebrate taxa that inhabit primarily terrestrial ecosystems. Trends associated with aquatic species and their

implications to aquatic system health are covered in a

companion report (see Loftus and Flather [In press]).

Although our definition of wildlife extends beyond the

traditional game bird and mammal focus, available data

on recent historical trends do have taxonomic biases that

can be traced to the recreational and commercial importance of some species. Such biases notwithstanding, our

intent is to discuss trends in wildlife resources across a

broad taxonomic set.1

1 The scientific name for species mentioned in this Assessment can be found in Appendix A.
2 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999

Flather, Brady, and Knowles Wildlife Resource Trends in the United States

We review trends in four attributes of wildlife resources: habitats, populations, harvests, and users. National-level summaries of emerging trends in these attributes set the context within which region-specific trends

are presented and discussed. Each region constitutes a

multi-state assessment area defined by the Forest Service

for strategic planning purposes and includes the North,

South, Rocky Mountain, and Pacific Coast Assessment

regions (figure 1). In some instances, data on wildlife

resources have been reported for regions that could not be

reaggregated to conform to the Assessment region boundaries defined for this report (e.g., waterfowl flyways).

Consequently, we also present wildlife resource trends

for other geographic regions when they are well established in wildlife planning.

The time period over which we review wildlife trends

varies among wildlife resource attributes and species. At

a minimum, we have attempted to document those trends

since the last RPA Assessment report (see Flather and

Hoekstra 1989). In most cases, however, the data permitted us to examine trends over the last 20 to 30 years. Our

review of the expected future condition of wildlife resource attributes was limited primarily to short-term (to

the year 2000) and long-term (to the year 2045) projections

provided by state wildlife agency personnel under an

assumption that current resource management strategies

would continue into the future.

The data that supported our examination of recent and

expected trends in wildlife resources came largely from

information that currently exists within Forest Service

and cooperating state and federal agency inventories. In

general, the data reviewed here were not collected specifically to support Forest Service RPA Assessments of

wildlife resources. Although there are specific cases of

standardized inventories that lend themselves to RPA

Assessments, there is a dearth of nationally consistent

environmental data from which to evaluate the ecological

condition of the United States in general (Brown and

Roughgarden 1990), and of wildlife resources in particular (Thomas 1990). Therefore, the extent to which we were

able to discuss habitat, population, harvest, and user

trends depended on the availability of information from

diverse sources.

This report is organized into three major sections. We

first review trends in broad classes of wildlife habitat,

which provide an indication of land resources available to

Figure 1. Forest Service RPA Assessment regions.

Pacific Coast

Rocky Mountain

North

South
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999 3

Wildlife Resource Trends in the United States Flather, Brady, and Knowles

wildlife. Second, trends in populations and harvests are

reviewed as indicators of species abundance and levels of

resource extraction. This section also reviews distributional patterns of threatened and endangered species as a

means of identifying those regions of the country where

imperiled species are concentrated. Third, we present

participation trends in wildlife-dependent recreation activities and trapping. We conclude by highlighting those

trends that appear to indicate favorable, uncertain, or

unfavorable resource conditions as a means of identifying

those resource situations that could benefit from resource

policy and land management attention.

Habitat Trends

Wildlife habitat is defined as the biotic and abiotic

attributes of a particular environment that, in total, make

it possible for a specified species to inhabit that environment (Morrison and others 1998). Habitat is often delineated geographically as an area within which the mix of

critical resources occur that provide for a species’ survival and reproduction. Because habitat is species specific, and can vary regionally, there are very few national

inventories of wildlife habitat per se. Even if such inventories existed, it would be difficult to gain a composite

perspective of wildlife habitat condition by integrating

habitat characteristics across species. For this reason, we

have chosen to discuss recent trends in wildlife habitat

using a broader definition of habitat—one that has its

basis in a landscape-ecologic perspective.

Block and Brennan (1993) define macrohabitat as landscape features that are correlated with the distribution

and abundance of species. Land use and land cover

classifications are two important landscape features that

can define macrohabitat classes, which can then be used

to infer the expected species composition for a particular

region. Using this approach, land use and land cover

statistics over time can provide a basis for anticipating the

response of species groups to changes in the amount and

management of various land classes. Here we address the

status of wildlife habitat by first examining general trends

in land use and land cover. This is followed by a specific

discussion of trends for forest, range, agriculture, and

wetland habitats.

General Land Use and Land Cover Trends

The distribution and abundance of wildlife is fundamentally affected by landscape structure, which is, in

turn, affected by vegetation cover and the manner in

which land is used by humans (Forman 1995, Janetos

1997). Human land use is the primary force driving

changes in biological diversity (Vitousek and others 1997).

Therefore, we examine recent trends in land use before

reviewing changes in species populations.

At the spatial and temporal scales of this Assessment,

we did not expect changes among major land use and

land cover categories to be extensive because (1) considerable land transformations occurred before the availability of comprehensive land area statistics and (2) available statistics tend to report only the net change over time,

which masks the dynamic nature of gross land area shifts

that actually occur among individual land types. Statistics for land area change of major land uses compiled by

the USDA Economic Research Service (1997) are consistent with this expectation (figure 2a). Area shifts in land

Figure 2. Trends in major (a) and minor (b) land uses for the conterminous United States (USDA Economic Research Service

1997). a

Includes land in parks, wilderness areas, wildlife areas, national defense and industrial areas, and miscellaneous

farmland uses. b

Includes land in highways, roads, and railroads.

1940 1950 1960 1970 1980 1990

Year

0

100

200

300

400

500

600

700

Acres (millions)Acres (millions)

a. b.

1940 1950 1960 1970 1980 1990

Year

0

20

40

60

80

100

120

Miscellaneous

Special use areas

Urban land

a

b

Rangeland

Forest-use land

Cropland

Cultivated cropland
4 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999

Flather, Brady, and Knowles Wildlife Resource Trends in the United States

use from 1945 to 1992 have been less than 11% for the three

major land uses that comprise 85% of the land area in the

conterminous United States—namely forest land, rangeland, and cropland.

Forest land use, which comprises about 30% of the land

base, has declined since 1945. Although land devoted to

forest-use increased through the mid-1950s, it declined at

an average annual rate of 4 million acres/year from the

mid-1960s to 1987. This shift from forest to other land

uses, however, must be interpreted cautiously. The conversion of land from forest-use does not necessarily reflect a conversion from forest cover. Much of the loss of

forest-use land actually reflects a greater percentage of

forests being classified as special use areas (e.g., parks,

wilderness, wildlife areas) rather than an actual reduction of land with forest cover. It was not possible to

determine the changes over time of land with forest cover

using the USDA Economic Research Service (1997) data.

Rangeland comprises the largest area among major

land uses, accounting for nearly a third of the total land

base in the lower 48. Since 1945, rangeland has declined

by nearly 11%, with the greatest decline occurring in the

late 1960s. Since the late 1960s, rangeland area has fluctuated from a high of 601 million acres in 1969 to a low of

584.3 million acres in 1978.

Cropland, which comprises about one quarter of the

land area in the lower 48 states, has shown essentially no

change since 1945—a trend that belies the dynamic nature

of cultivated land. The area of cropland that is cultivated

for growing crops has actually declined by 7% over the

1945-1992 period. In addition, cultivated cropland has

fluctuated over time due to the enrollment of land in

various Federal programs that retire acres from production for specified periods of time.

Land use categories that comprise a smaller proportion of the land base show much greater relative acreage

changes over time when compared to the major land use

categories (figure 2b). This is particularly apparent with

urban land uses (including transportation lands) that

have increased consistently from 37.6 million acres in

1945 to nearly 83 million acres in 1992. This represents

a 120% increase, although urban land comprised only

about 4% of the land base in 1992. Other special use

lands, which includes Federal and State parks, wilderness areas, wildlife areas, national defense areas, and

miscellaneous farmland uses, also changed greatly over

the 1945-1992 period relative to the other land use

categories. The nearly 80% gain in this category (from

62.5 million acres in 1945 to 111.7 million acres in 1992)

reflects the designation of lands for conservation and

recreational purposes.

Recent trends in land use and land cover based on data

from the 1992 National Resources Inventory (NRI; USDA

Natural Resources Conservation Service 1994) are consistent with the previously reviewed long-term trends. The

NRI is a periodic (5-year interval) inventory that monitors

land use and land cover on nonfederal lands. We used the

NRI to examine land use and land cover trends by Assessment region from 1982 to 1992. A detailed accounting of

land use and land cover dynamics from 1982 to 1992 for

the nation and by RPA region is provided in Appendix B.

Since 1982, cropland area has declined by 11%, with the

loss being concentrated in the South and Rocky Mountain

regions (table 1). This loss can be traced directly to the

Table 1--Recent (1982-1992) land area changes for major land uses on non-federal lands (USDA Natural Resources Conservation Service 1994). 

 Cropland (cultivated) Cropland (uncultivated) Pastureland Rangeland 

Region 1982 1992 Change 

 (%) 

1982 1992 Change 

 (%) 

1982 1992 Change 

(%) 

1982 1992 Change 

(%) 

-------------------------------------------------------------------------------------------------------------------------thousand acres-------------------------------------------------------------------------------------------- 

North 130,082.2 121,081.8 -9,000.4 

(-6.9) 

24,159.4 24,646.3 486.9 

(2.0) 

45,686.1 39,640.1 -6,046.0 

(-13.2) 

169.1 126.4 -42.7 

(-25.3) 

South 98,687.1 81,929.8 -16,757.3 

(-17.0) 

7,960.2 8,948.6 988.4 

(12.4) 

64,944.8 65,356.1 411.3 

(0.6) 

115,411.1 112,135.1 -3,276.0 

(-2.8) 

Rocky Mtn. 119,727.6 107,298.5 -12,429.1 

(-10.4) 

16,961.0 17,198.4 237.4 

(1.4) 

15,682.1 15,717.5 35.4 

(0.2) 

259,186.8 253,626.5 -5,560.3 

(-2.1) 

Pacific 

Coasta

 

17,352.2 14,869.3 -2,482.9 

(-14.3) 

5,622.6 5,977.4 354.8 

(6.3) 

 4,783.8 4,501.1 -282.7 

(-5.9) 

33,973.7 32,915.4 -1,058.3 

(-3.1) 

Total U.S. 365,849.1 325,179.4 -40,669.7 

(-11.1) 

54,703.2 56,770.7 2,067.5 

(3.8) 

131,096.8 125,214.8 -5,882.0 

(-4.5) 

408,740.7 398,803.4 -9,937.3 

(-2.4) 

a

Does not include Alaska 

b

Although the NRI is an inventory of nonfederal lands, it does report acres in federal ownership to maintain a complete accounting of land area in the United States. Land use and land cover 

characteristics are not inventoried on federally owned land. 
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999 5

Wildlife Resource Trends in the United States Flather, Brady, and Knowles

Table 1--(Cont'd.) 

Forest Urban Water Other Federalb

 1982 1992 Change 

(%) 

 1982 1992 Change 

(%) 

 1982 1992 Change 

(%) 

 1982 1992 Change 

(%) 

1982 1992 Change 

 (%) 

------------------------------------------------------------------------------------------------------------------------------thousand acres------------------------------------------------------------------------------------------------------------------ 

146,810.9 148,159.0 1,348.1 

(0.9) 

31,177.2 35,235.2 4,058.0 

(13.0) 

14,572.5 14,736.5 164.0 

(1.1) 

17,214.4 25,849.3 8,634.9 

(50.2) 

15,424.5 15,821.7 3,972.0 

(2.6) 

176,921.1 177,334.4 413.3 

(0.2) 

28,745.7 35,692.6 946.9 

(24.2) 

20,417.9 21,176.9 759.0 

(3.7) 

13,753.9 22,985.2 9,231.3 

(67.1) 

 4,690.7 25,973.8 1,283.1 

(5.2) 

 28,837.8 28,281.4 -556.4 

(-1.9) 

11,298.6 12,871.3 1,572.7 

(13.9) 

 9,031.2 9,143.0 111.8 

(1.2) 

15,265.0 31,202.4 15,937.4 

(104.4) 

273,458.5 274,109.6 651.1 

(0.2) 

 41,275.5 40,662.1 -613.4 

(-1.5) 

6,871.0 8,146.6 1,275.6 

(18.6) 

 3,948.3 3,806.5 -141.8 

(-3.6) 

 6,540.3 8,527.7 

 

 1,987.4 

(30.4) 

91,032.8 91,994.1 961.3 

(1.1) 

393,845.3 394,436.9 591.6 

(0.1) 

78,092.5 91,945.7 13,853.2 

(17.7) 

47,969.9 48,862.9 893.0 

(1.9) 

52,773.6 88,564.6 35,791.0 

(67.8) 

404,606.5 407,899.2 3,292.7 

(0.8) 

Conservation Reserve Program (CRP), which enabled

farmers to voluntarily retire highly erodible or environmentally sensitive cropland from production and convert

it to perennial vegetation in exchange for annual rent

payments. Although the gains in uncultivated cropland

are consistent with the CRP retirements, the increased

acreage in this land use class is due mostly to increases in

hayland acreages and does not account for the CRP

enrollment. Because of the long-term nature of CRP retirement contracts (10-15 years), the NRI chose to classify

CRP lands as “other land” and the 35 million acres gained

in this land use category is directly attributable to the

CRP. Pastureland area also declined from 1982 to 1992

nationwide. Although there were minor gains in

pastureland in the South and Rocky Mountains, the North

lost more than 13% of its 1982 pastureland base.

Rangeland area declined in all Assessment regions

since 1982 (table 1). We make a distinction between

rangelands and patureland in that rangelands typically

consist of native plant communities managed by the

timing and intensity of grazing, but generally without

agronomic management practices applied such as cultivation, planting, and fertilization. The greatest acreage

declines occurred in the South and Rocky Mountains,

which lost more than 3.2 and 5.5 million acres, respectively. The greatest proportional declines occurred in

those regions with the fewest rangeland acres—declining

by 3% in the Pacific Coast and by more than 25% in the

North. Although rangeland habitats are rare in the North,

this trend coupled with trends in pastureland appear to

stem from natural successional processes in the absence

of new disturbance (e.g., farm abandonment, fire).

Forest land changes varied among Assessment regions

(table 1). Forest habitats increased by about 1.3 million acres

in the North and by more than 410,000 acres in the South

during the 1982-92 decade. Conversely, forest land area

declined in the West, but by less than 2% in both the Rocky

Mountain and Pacific Coast regions. Viewed nationally,

these forest land dynamics negated each other, resulting

in no net change of total forest area on nonfederal lands.

Urban land uses, including transportation networks,

displayed consistent and substantial gains (greater than

10%) in all regions (table 1). The South witnessed notable

urban growth, gaining nearly 7 million acres (a 24%

increase) over the decade. The area covered by water

showed increases in the North, South, and Rocky Mountains, with small declines in the Pacific Coast. Changes in

water area are due to reservoir construction and to wet

and dry climate cycles.

Finally, the amount of land in Federal ownership actually increased over this 10-year period (less than 1%

nationwide), most notably in the North and South (table 1).

Although the NRI is an inventory of nonfederal land, it

does report land ownership changes involving federal

lands. This is necessary to have a complete accounting of

land area changes. However, once land is owned by the

federal government the NRI no longer tracks land use and

land cover characteristics on those acres.

Forest Habitats

Forests in the United States are extensive and diverse

with nearly a third of the landbase supporting forest
6 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999

Flather, Brady, and Knowles Wildlife Resource Trends in the United States

Region Year 

Whitejackred pine Longleafslash 

pine 

Loblollyshortleaf 

pine 

Sprucefir Oakpine Oakhickory 

Oakgumcypress 

Elm-ashcottonwood 

Maplebeechbirch 

Aspenbirch 

 -------------------------------------------------------------------------thousand acres-------------------------------------------------------------------------

Northa 1963 10,680 - 3,818 19,623 2,266 58,896 1,678 18,301 32,812 23,715

 1970 11,910 - 3,422 18,899 4,085 55,536 1,361 21,971 30,657 20,484

 1977 11,455 - 3,423 17,552 4,170 49,956 623 19,074 35,821 19,243

 1987c 13,349 - 2,340 16,825 3,550 47,124 795 11,283 43,384 17,774

 1992c 12,906 - 2,310 17,752 3,371 49,431 709 11,053 46,053 16,387

 % changee 20.84 - -39.50 -9.53 48.76 -16.07 -57.75 -39.60 40.35 -30.90

 

Southb

 1963 440 25,977 54,177 15 24,675 57,067 36,110 2,102 506 -

 1970 257 18,314 49,409 13 30,942 56,324 29,268 2,756 482 -

 1977 370 16,754 46,576 8 30,470 58,939 26,062 3,243 425 -

 1987d 514 15,491 46,248 18 27,775 70,559 27,332 3,007 876 -

 1992d 609 14,130 47,014 13 28,585 74,527 27,477 2,618 1,089 -

 % changee 38.41 -45.61 -13.22 -13.33 15.85 30.60 -23.91 24.55 115.22 -

 

Total East 1963 11,120 25,977 57,995 19,638 26,941 115,963 37,788 20,403 33,318 23,715

 1970 12,167 18,314 52,831 18,912 35,027 111,860 30,629 24,727 31,139 20,484

 1977 11,826 16,755 49,999 17,560 34,639 108,895 26,685 22,318 36,246 19,243

 1987 13,863 15,481 48,588 16,843 31,325 117,683 28,127 14,290 44,219 17,774

 1992 13,516 14,130 49,324 17,765 31,955 123,958 28,186 13,671 47,139 16,387

 % changee 21.55 -45.61 -14.95 -9.54 18.61 6.89 -25.41 -33.00 41.48 -30.90

a

Includes ND, SD (east), NE, KS, and KY. 

b

Does not include KY. 

c

Does not include KY, includes SD (east and west). 

d

Includes KY. 

e

Percent change from 1963 to 1992. 

cover. This amounts to about 70% of the total land area in

forest cover that was present at the time of European

settlement (Powell and others 1993). Forest land is defined as land at least 10% stocked by forest trees of any

size, including land that formerly had such cover and will

be naturally or artificially regenerated to trees (USDA

Forest Service 1981). It has been estimated that 90% of the

resident or common migrant vertebrate species in the

United States use forest habitats to meet at least part of

their life requisites.2

Based on data from the NRI, just over 96% of the

nonfederal land that was in forest cover in 1982 remained

in forest cover in 1992 (Appendix B). Of the 14.7 million

acres of forest land that was transformed, most (38%) was

converted to urban or transportation lands. About 27% of

converted forest land went into pasture or rangeland, and

about 13% went into federal ownership. Only about 10%

of the converted forest acres went into cropland.

Although these statistics imply a fairly stable forest

land base, there have been some substantial shifts in the

character of forest ecosystems that can greatly affect the

distribution and abundance of wildlife. Based on forest

inventory information for timberland (i.e., land capable

of producing 20 cubic feet of wood per acre per year, and

which is available for successive harvests of timber products [USDA Forest Service 1982]), changes in forest cover

types and changes in successional stages reveal more

dynamics in forest habitats than implied by general forest

land area changes (tables 2 and 3). Unfortunately, forest

inventory techniques, standards, and geographical definitions have changed over time making it difficult to

interpret recent historical trends in forest cover types and

successional stages. In addition, interpretation of these

trends must be mindful of the fact that timberland can be

converted to another status through the designation of

parks and wilderness without affecting the forest cover

type class or successional stage.

Forest cover types discussed here are those defined by

the Forest-Range Environment Study (Garrison and others 1977). In the eastern United States, forests are dominated by the oak-hickory cover type which comprised

Table 2—Recent trends in eastern timberland area by forest ecosystem types (USDA Forest Service [1965, 1974, 1982];

Haynes [1990]; Powell and others [1993]).

2 USDA Forest Service. 1979. The 1979 wildlife and fish data

base. Data base stored at the Rocky Mountain Research

Station.
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999 7

Wildlife Resource Trends in the United States Flather, Brady, and Knowles

about 35% of the total timberland in 1992. Not only is oakhickory the most common cover type in the east, but more

than 15 million acres have been added to this cover class

since 1977 (table 2). The amount of timberland classified

as maple-beech-birch has also increased greatly in the last

few decades. Since 1970, the area of maple-beech-birch

forest has increased by 16 million acres and it now comprises just over 13% of the eastern timberland base.

Loblolly-shortleaf pine is currently the second most common eastern cover class (nearly 14% of the timberland

base), but it has declined by nearly 15% since 1963. Other

eastern cover types that have declined substantially since

1963 include longleaf-slash pine (-46%), elm-ash-cottonwood (-33%), aspen-birch (-31%), and oak-gum-cypress (-

25%).

Forest cover types in the West are dominated by conifers (table 3). Douglas-fir, ponderosa pine, and fir-spruce

together comprise nearly 70% of the total timberland area

in the West. The area classified as Douglas-fir and ponderosa pine has declined by 3 and 10 million acres, respectively. The fir-spruce cover class has actually gained more

than 11 million acres. Western hardwoods (e.g., oak, red

alder, and aspen) are important for wildlife habitat and

watershed protection. Western hardwoods increased in

area from 1963 to 1992 by nearly 40% and have increased

in value as fuelwood, lumber, specialty millstock, and

pulp chips (Powell and others 1993). Western forest cover

types that have declined by more that 25% since 1963

include western white pine, larch, ponderosa pine, lodgepole pine, and redwood.

Trends in forest cover classes that are of particular

concern are those that have been identified to be critically

endangered ecosystems. A critically endangered ecosystem, as defined by Noss and others (1995), is one in which

the presettlement extent of the system has been reduced

by more than 98%. Noss and others (1995) identified the

following forest ecosystems as critically endangered:

spruce-fir forests in the southern Appalachians, red and

white pine forests in Michigan, longleaf pine forests and

savannas in the southeastern coastal plain, slash pine

rockland habitat in southern Florida, loblolly/shortleaf

pine-hardwood forests in the west gulf coastal plain,

Atlantic white-cedar in the Great Dismal Swamp of Virginia and North Carolina, and oak savannas in the Midwest, Willamette Valley, and foothills of the Oregon Coast

Range. Of particular note in Noss’ list are the southern

pine types (loblolly-shortleaf and longleaf-slash) that we

reported earlier as having lost substantial timberland

acres (see table 2).

Stand size class is another characteristic of forest cover

that can be used to describe the structure and age of forest

ecosystems (table 4). Nationally, there have been substanTable 3—Recent trends in western timberland area by forest ecosystem types (USDA Forest Service [1965, 1974, 1982];

Haynes [1990]; Powell and others [1993]).

Douglas Ponderosa Western Fir- Hemlock- Lodgepole Other Western

Region Year fir pine white pine spruce Sitka spruce Larch pine Redwood softwood hardwood

 ---------------------------------------------------------thousand acres ---------------------------------------------------------

Rockya 1963 13,447 18,881 2,360 8,962 200 2,669 13,163 - - 5,941

 Mountain 1970 11,885 14,454 631 9,800 896 2,032 9,940 - - 4,272

1977 12,220 14,673 320 10,124 1,246 1,749 9,816 - 507 4,555

1987b 13,304 13,714 260 11,009 1,489 1,749 9,397 - 301 4,810

1992b 13,817 14,237 191 11,196 1,573 1,742 9,106 - 671 4,960

% changec 2.75 -24.60 -91.91 24.93 686.50 -34.73 -30.82 - 32.35 -16.5

Pacific 1963 23,905 17,116 2,643 6,654 9,808 863 2,633 1,596 - 5,146

 Coast 1970 18,902 13,509 198 8,029 9,922 711 3,294 803 - 8,545

1977 18,677 11,976 126 9,732 11,620 683 2,919 662 - 10,308

1987 19,023 10,927 14 15,843 9,495 852 2,178 1,102 492 11,028

1992 20,718 11,015 13 15,748 6,715 350 1,997 1,148 492 10,346

% changec -13.33 -35.65 -99.51 136.67 -31.54 -59.44 -24.15 -28.07 0 101.05

Total West 1963 37,352 35,997 5,003 15,616 10,008 3,532 15,796 1,596 - 11,087

1970 30,787 27,963 829 17,829 10,818 2,743 13,234 803 - 12,817

1977 30,897 26,649 446 19,856 12,866 2,432 12,735 662 507 14,862

1987 32,327 24,641 274 26,852 10,984 2,601 11,575 1,102 793 15,838

1992 34,535 25,252 203 26,945 8,290 2,091 11,103 1,148 1,164 15,306

% changec -7.54 -29.85 -95.94 72.55 -17.17 -40.80 -29.71 -28.07 129.59 38.05

a

Does not include ND, SD (east), NE, and KS.

b

Does not include SD (east and west).

c

Percent change from 1963 to 1992.
8 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999

Flather, Brady, and Knowles Wildlife Resource Trends in the United States

tial reductions (nearly 80%) in the number of acres that are

nonstocked (i.e., forest cover that is less than 10% stocked

with growing stock trees). The area in seedlings and

saplings (less than 5 inches diameter at breast height

[dbh]) has remained essentially unchanged from 1963 to

1992; poletimber (greater than 5 inches dbh, but less than

sawtimber) has declined by more than 25%; and sawtimber (greater than 9 inches dbh for softwoods, greater than

11 inches dbh for hardwoods) has increased by nearly

25%.

Increases in sawtimber appear to be caused primarily

by maturing eastern forests. The area of timberland in

sawtimber has increased by more than 50% in the North

and by nearly 30% in the South from 1963 to 1992 (table 4).

In the West, the area in sawtimber increased by more than

10% in the Rocky Mountain region, but declined by nearly

Table 4—Trends in stand-size class by RPA Assessment region (USDA Forest Service [1965, 1974, 1982]; Haynes [1990];

Powell and others [1993]).

Total Rockyc Pacific

Class Year U.S. Northa Southb Mountain Coast

-----------------------------------------------------thousand acres-----------------------------------------------------

Sawtimber 1963 208,945 52,974 68,828 38,639 48,504

1970 215,876 58,949 74,041 36,555 46,321

1977 215,435 59,098 71,246 38,545 46,545

1987 242,449 74,548d 78,321e 41,981f 47,599

1992 259,879 81,116d 88,975e 43,339f 46,449

% changeg 24.38 53.12 29.27 12.16 -4.24

Poletimber 1963 164,794 64,808 71,580 19,063 9,343

1970 126,794 60,156 46,151 12,129 8,256

1977 135,610 55,543 58,316 11,708 10,042

1987 136,773 60,445 54,888 9,454 11,986

1992 120,788 48,120 53,348 8,653 10,667

% changeg -26.70 -25.75 -25.47 -54.61 14.17

Seedling 1963 99,573 39,327 49,254 4,352 6,640

sapling 1970 131,368 49,223 67,578 5,229 9,337

1977 115,032 46,676 53,286 4,955 10,115

1987 92,436 31,547 44,883 5,323 10,683

1992 101,417 30,743 53,736 5,501 11,437

% changeg 1.85 -21.83 9.10 26.40 72.24

Nonstocked 1963 35,533 14,680 11,407 3,569 5,877

1970 20,721 9,571 4,771 2,671 3,707

1977 16,408 4,823 5,198 2,556 3,831

1987 11,649 2,247 5,380 2,186 1,836

1992 7,471 1,348 3,250 1,607 1,266

% changeg -78.97 -90.82 -71.51 -54.97 -78.46

All 1963 508,845 171,789 201,069 65,623 70,364

1970 499,692 177,901 192,542 61,631 67,622

1977 482,485 166,141 188,045 57,765 70,543

1987 483,309 168,788 183,473 58,944 72,104

1992 489,555 161,328 199,309 59,099 69,819

% changeg -3.79 -6.09 -0.88 -9.94 -0.77

a Includes ND, SD (east), NE, KS, and KY.

b

 Does not include KY.

c

 Does not include ND, SD (east), NE and KS.

d

 Does not include KY; includes SD (east and west).

e

 Includes KY.

f

 Does not include SD (east and west).

g Percent change from 1963 to 1992.
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999 9

Wildlife Resource Trends in the United States Flather, Brady, and Knowles

5% in the Pacific Coast over the same period. The acreage

in poletimber has declined by more than 25% in all regions

except the Pacific Coast where it has increased by 14%.

Although the acreage in the seedling/sapling stage has

remained stable at the national level, the North has actually lost 22% of the timberland area in this stand size class

over the last three decades. This loss is more than offset by

gains in the seedling/sapling stage across all other Assessment regions. The number of acres classified as

nonstocked has declined in all regions since 1963, with the

North (91% decline) and the Pacific Coast (78% decline)

undergoing the greatest proportional reductions.

Although eastern forests appear to be maturing, stand

size class does not adequately capture the structural

characteristics of old-growth or ancient forests. Consequently, Noss and others (1995) identified old-growth

eastern deciduous forests as critically endangered. Oldgrowth and ancient forests, in general, and old-growth

ponderosa pine forests, in particular, were listed by Noss

and others (1995) as endangered (i.e., reductions of 85 to

98%) in the western United States.

Rangeland Habitats

Rangeland habitats include those areas where the potential natural vegetation is comprised predominately of

grasses, grass-like plants, forbs, or shrubs and where

herbivory was an important ecological disturbance shaping plant life history (Anderson and others 1976). Rangelands have traditionally been evaluated in terms of livestock production (Busby 1994). There is, however, a

growing emphasis on evaluating rangeland habitats from

a system health perspective (Committee on Rangeland

Classification 1994) that includes a broader understanding of the importance of rangeland in the maintenance of

biological diversity. The importance of this perspective

becomes more meaningful if one considers that rangeland

habitats are used, during some period of the year, by 84%

of the mammals and 74% of the bird species that are

inhabitants or common migrants in the United States.3

Although there is a growing recognition that assessing

rangeland health is a critical conservation need, data

constraints impede such assessments. According to the

Committee on Rangeland Classification (1994), all existing national rangeland assessments suffer from the lack of

current and comprehensive field data. Because rangeland

inventories have used different methods and sources

over time, it is not possible to aggregate these data for

national summaries of trends in rangeland condition. For

these reasons, our discussion of the status of rangeland

habitats will be limited.

Based on data from the NRI, there has been a 2.4% net

loss of nonfederal rangeland area nationwide from 1982

to 1992 (see table 1). Of the rangeland acres converted, the

largest proportion was converted to cropland (33%);

nearly 20% was converted to federal ownership; 14% was

converted to pastureland; just over 12% was converted to

urban or transportation land; and nearly 9% was converted to forest (Appendix B).

Conversion of rangeland does not address the condition of those acres that remain in range habitats. Past

evaluations of range condition are currently a topic of

much debate and there is no agreement on how best to

assess range condition (Committee on Rangeland Classification 1994). A recent examination of conservation treatment needs on private rangelands in the western United

States showed that of the 394.8 million acres of private

rangeland in the West, nearly 60% were in need of some

management to correct for disturbances that were affecting productive capacity (USDA Natural Resources Conservation Service 1997:33). Brush and weed problems

were implicated as the primary agent that reduced productivity on 17% of the rangeland acres; accelerated wind

and water erosion was a problem on 23% of the acres; and

multiple factors affected 18% of the acres. Unfortunately,

the basis for assessments of rangeland condition has

changed over time, making it impossible to determine

whether rangeland health is improving or deteriorating.

In evaluating the state of rangeland habitats, it is

important to recognize that recent land area dynamics or

conservation needs assessments do not indicate the extent to which certain rangeland systems have been altered

historically. Many rangeland ecosystems had undergone

extensive conversions long before land base inventories

were designed. In an examination of the status of the

nation’s ecosystems, Noss and others (1995:5) found that

grasslands and shrublands were disproportionately represented among those ecosystems identified as critically

endangered (i.e., more than 98% of their historic areal

extent had been lost). Approximately 55% of the critically

endangered ecosystems were grasslands and 24% were

shrubland systems. For comparison, 17% of the critically

endangered ecosystems were forests, 2% were forested

wetland, and 2% were aquatic.

If we broaden Noss and others’ (1995) list of critically

endangered ecosystems to include those systems that are

thought to be endangered (85-98% of their historic areal

extent has been lost), then the distribution of these imperiled rangeland systems by Assessment region is about

equal. Six occur in the Rocky Mountain region, seven

occur each in the North and Pacific Coast regions, and

nine occur in the South (table 5). This balance across

Assessment regions was somewhat surprising given the

3 USDA Forest Service. 1979. The 1979 wildlife and fish data

base. Data base stored at the Rocky Mountain Research

Station.
10 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999

Flather, Brady, and Knowles Wildlife Resource Trends in the United States

Table 5--Rangeland ecosystems considered to be endangered or critically endangered (from Noss and others 1995). 

Ecosystem RPA Region where found Comments 

Tallgrass prairie east of the 

Missouri River 

North, Rocky Mountain Chapman (1984), and Klopatek and others (1979) have 

estimated that 99% of the tallgrass prairie east of the 

Missouri has been lost. 

Arundinaria gigantea

canebrakes in the Southeast 

South Extensive canebrake habitats are nearly all lost with the 

majority of the remaining habitat occurring as an understory 

plant or along fencelines (Platt and Brantley 1992) 

Bluegrass savanna-woodland 

and prairies in Kentucky 

South Nearly all intact bluegrass savanna-woodland and native 

prairie have been losta

. Of the 2.6 million acres of native 

prairie, less than 200 acres remain (Mengel 1965, Kentucky 

Environmental Quality Commission 1992) 

Black Belt prairies in Alabama 

and Mississippi and the 

Jackson Prairie in Mississippi 

South All but a few remnant patches of these prairie systems 

remain following conversion to agriculture (DeSelm and 

Murdock 1993) 

Dry prairie habitats in Florida South Virtually all of the dry prairies in Florida have been lost to 

cattle pasture and agriculture (DeSelm and Murdock 1993) 

Oak savanna in the Midwest North More than 99% of the original oak barrens and savannas 

have been lost in Wisconsin, Missouri, Michigan, and 

Minnesota (Nuzzo 1985, 1986, Nelson 1985, Henderson and 

Epstein 1995) 

Wet and mesic coastal prairies 

in Louisiana 

South More than 99% of the original wet and mesic prairies have 

been lost in Louisianab

Lakeplain wet prairie in 

Michigan 

North More than 99% of this habitat has been lost with only about 

500 acres persisting (Chapman 1984) 

Hempstead Plains grasslands 

on Long Island, New York 

North More than 99% of the grassland system has been lost 

(Niering 1992)c

Serpentine barrens, maritime 

heathland, and pitch pine-heath 

barrens in New York 

North A probable 98% loss of these habitatsc

Prairies and oak savannas in 

the Willamette Valley and 

Coast Range foothills in 

Oregon 

Pacific Coast Since European settlement, more than 99% of these habitats 

have been lost (Ingersoll and Wilson 1991) 

Palouse prairie Pacific Coast, Rocky 

Mountain 

Nearly all of the Palouse prairie has been lost to agricultural 

development throughout its range (Tisdale 1961) 

California native grasslands Pacific Coast Of the original 22 million acres of native grasslands in 

California, 22 thousand acres remain (Kreissman 1991) 

Alkali sink scrub in southern 

California 

Pacific Coast Alkali sink scrub habitats have been nearly extirpated in 

southern California (Freas and Murphy 1988) 

Coastal strand in southern 

California 

Pacific Coast All coastal strand habitats in San Diego county have been 

lostd

Sagebrush steppe in the 

Intermountain west 

Rocky Mountain Most (greater than 99%) of the remaining sagebrush steppe 

habitats have been affected by grazing; 30% has been 

overgrazed; species composition is dominated by a few 

woody plants (West 1996) 
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999 11

Wildlife Resource Trends in the United States Flather, Brady, and Knowles

Table 5--(Cont'd.) 

Ecosystem RPA Region where found Comments 

Basin big sagebrush in the 

Snake River Plain of Idaho 

Rocky Mountain Most of the big basin sagebrush habitats have been 

converted to agriculture (Hironaka and others 1983) 

Coastal heathland in southern 

New England 

North About 90% of this habitat has been destroyed since the mid1800s (Godfrey and Alpert 1985) 

Limestone redcedar glades in 

Tennessee 

South About 90% of ecologically intact limestone cedar glades have 

been loste

Calcareous prairie, Fleming 

glade, and stream terrace 

sandy woodland/savanna in 

Louisiana 

South 90 to 99% of these habitats have been lostb

Coastal sage scrub and coastal 

mixed chaparral in southern 

California 

Pacific Coast 70 to 90% of the southern California coastal scrub has been 

destroyed (Westman 1981, O'Leary 1990). Nearly 92% of the 

maritime sage scrub and 88% of coastal mixed chaparral has 

been lost in San Diego Countyd

Grassland and shrubland 

habitats of the lower Rio 

Grande River delta 

South 95% of the native habitat in the lower delta of the Rio Grande 

River has been lost; habitat that remains is highly fragmented 

(Riskind and others 1987) 

Tallgrass prairie in general North, South, Rocky 

Mountain 

Of the nearly 145 million acres of tallgrass prairie, 90% has 

been lost; areas remaining in tallgrass prairie are highly 

fragmented (Madson 1990) 

Native shrub and grassland 

steppe in Oregon and 

Washington 

Pacific Coast Greater than 90% of this habitat has been lost in Oregon and 

southwestern Washington (The Nature Conservancy 1992) 

Low elevation grasslands in 

Montana 

Rocky Mountain 80 to 90% loss of this habitat in western Montanaf

a

Personal communication. T. Bloom, Kentucky Nature Preserves Commission, Frankfort, KY. As cited in Noss and others (1995). 

b

Smith, L.M. 1993. Estimated presettlement and current acres of natural plant communities in Louisiana currently recognized by the 

Louisiana Natural Heritage Program, January 1993. Unpublished table. Louisiana Department of Wildlife and Fisheries, Natural 

Heritage Program, Baton Rouge. As cited in Noss and others (1995). 

c

Reschke, C. 1993. Estimated numbers of EOs, acreage, trends, and threats for selected New York natural communities. 

Unpublished report. New York State Department of Environmental Conservation, Natural Heritage Program, Lathan. As cited in 

Noss and others (1995). 

d

Oberbauer, T.A. 1990. Areas of vegetation communities in San Diego County. Unpublished report. County of San Diego, 

Department of Planning and Land Use, San Diego, CA. As cited in Noss and others (1995). 

e

Pyne, M.; Durham, D. 1993. Estimation of losses of ecosystems in Tennessee. Unpublished table. Tennessee Department of 

Environment and Conservation, Ecological Services Division, Nashville. As cited in Noss and others (1995). 

f

Chadde, S. 1992. Decline of natural ecosystems in Montana. Unpublished report. U.S. Forest Service, Missoula, MT. As cited in 

Noss and others (1995). 
12 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999

Flather, Brady, and Knowles Wildlife Resource Trends in the United States

regional distribution of rangelands. About 53% of all

rangelands are found in the Rocky Mountain region, 26%

are found in the Pacific Coast, 15% are found in the South,

and less than 1% occurs in the North (Bones and others

1989). Whereas rangeland habitats are relatively rare in

the eastern United States, more than half of the endangered grassland systems listed by Noss and others (1995)

occur there. This disproportionate representation of endangered grassland and shrubland systems in the East is

likely a product of their rarity. Given that much of the East

naturally supports forest vegetation, the maintenance of

grassland and shrubland systems in these landscapes is

due, in part, to periodic disturbance. If the frequency of

natural disturbance events is altered, then grassland and

shrubland systems may be lost to uninterrupted successional processes.

A review of the factors that have contributed to the loss

of grass and shrublands appears to support this explanation. Noss and Peters (1995) identified agricultural development, fire suppression, urban development, and exotic

species invasions as the primary agents of grass and

shrubland system degradation and destruction. Tallgrass

prairie habitats have been lost primarily to agricultural

development. Eastern and Northwestern grasslands and

savannas have been lost to urban development, agriculture, and fire suppression. These factors are also prominent in the loss of native California grasslands, but exotic

species invasions have also played a major role in the loss

of these grassland habitats (Barbour and others 1991).

Use of rangeland habitats by livestock has shown a

general decline over the last two decades (figure 3).

Nationally, the number of cattle has declined by about

22% from the mid-1970s to 1996 (figure 3a). Cattle numbers have also declined in each Assessment region. The

greatest decline, both in terms of absolute numbers and

relative change, occurred in the North with cattle numbers declining by 12.7 million head (-33%). Substantial

declines in the number of cattle have also been reported

in the South (-10.3 million head, or -21%). Reductions in

the Rocky Mountain and Pacific Coast have been more

moderate over this time period. Although the long-term

trend has shown a decline, cattle numbers have increased

since the last Assessment. Cattle numbers have increased

by more than 5% nationwide since 1989 due to gains

reported in the Rocky Mountain (+13%) and Southern

(+8%) regions (figure 3a).

Sheep numbers have shown even greater declines

when compared to cattle (figure 3b). Since 1975, the

number of sheep has declined by nearly 52%, nationally.

Although the greatest decline was observed in the Rocky

Mountains (-56%), all Assessment regions have exhibited

declines by more than 40% over the last 20 years. Unlike

cattle, there is no evidence of any recent departure from

this long-term decline.

Figure 3. Trends in number of cattle (a) and sheep (b) from 1975 to 1996 for the United States and RPA Assessment region

(Mitchell [In press]).

a. b.

1975 1980 1985 1990 1995

Year

0

20

40

60

80

100

120

140

Number of cattle (millions)

Number of sheep (millions)

South

Pacific Coast

Rocky Mountain

North

Total

1975 1980 1985 1990 1995

Year

0

2

4

6

8

10

12

14

Total

Rocky Mountain

South

North

Pacific Coast
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999 13

Wildlife Resource Trends in the United States Flather, Brady, and Knowles

The declining trend in livestock numbers also is reflected in the permitted Animal Unit Months (AUMs) on

Forest Service and Bureau of Land Management (BLM)

lands (figure 4), although the magnitude of the decline is

less. Total permitted AUMs have declined by 7 and 20%

on Forest Service and BLM lands, respectively. The greatest proportional decline on Forest Service lands occurred

in the South (-49%), followed by the Pacific Coast (-12%),

North (-10%), and the Rocky Mountains (-5%). On BLM

lands the number of permitted AUMs in the Rocky Mountains and Pacific Coast declined by 17 and 36%, respectively.

Livestock numbers may not accurately reflect use or

quality of rangeland habitats. Livestock often are concentrated in feedlot production sites for all (e.g., hogs)

or a portion (e.g., cattle) of the production cycle. New

production and processing technologies have resulted

in livestock concentrations that have not been observed

in the past (USDA Natural Resources Conservation

Service 1997). Although growth in concentrated animal

production operations has the potential to reduce impacts associated with grazing on open range, such

concentrations pose a different set of environmental

impacts associated with animal manure and the contamination of aquatic habitats (USDA Economic Research Service 1997).

Agricultural Habitats

Agricultural habitats consist primarily of lands used to

produce food, feed, fiber, and oilseed crops, and therefore are described as cropland and pastureland. This

excludes tree farms and commercial forests. Almost all

croplands are owned by the private sector. Small amounts

of cropland occur on federal wildlife refuges to produce

food for migratory waterfowl and other species, but they

will not be discussed here. Cropland can be readily

divided into two categories: cultivated and noncultivated.

Cultivated cropland is annually planted for commodities

including rowcrops such as corn, soybeans, and cotton or

small grains such as wheat and oats. Noncultivated cropland consists of land planted to multi-year or perennial

crops such as hay, horticultural plants, and orchards.

Pastureland is land used for livestock grazing and differs

from rangeland in the level of management it receives.

Pasturelands are planted primarily to introduced or domesticated native forage species and receive periodic

cultural treatments such as tillage, fertilization, mowing,

weed control, or irrigation (Jacoby 1989).

Agricultural lands provide food and cover used by

many species of wildlife, and many agricultural cropping

practices are used in managing habitats for some wildlife.

Intensive agricultural land use becomes detrimental to

Figure 4. Number of permitted AUMs on public lands (Forest Service and BLM) in 1986 compared to 1992 (Mitchell [In press]).

0.08 0.24

8.42

1.34

10.07

10.9

1.61

12.53

0.07 0.12

7.98

1.18

9.36 9.05

1.03

10.09

North South Rocky Pacific Total North South Rocky Pacific Total

0

2

4

6

8

10

12

14

Permitted AUMs (millions)

1986

1992

Mtn Coast Coast Mtn

Forest Service Bureau of Land Management
14 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999

Flather, Brady, and Knowles Wildlife Resource Trends in the United States

wildlife when it is applied extensively over large contiguous tracts, when adjacent native habitats are converted to

agricultural production, when land is farmed beyond its

capacity resulting in excessive soil erosion, or when pesticides are applied inappropriately. Sound land stewardship that integrates agricultural production with habitat

management and ecological processes can mitigate some

of these adverse effects (Dumke and others 1981, Brady

1985, Warner and Brady 1994).

Cultivated cropland represented about 17%,

noncultivated cropland represented about 3%, and pasture accounted for about 6% of the nonfederal land in the

United States in 1992 (Appendix B). Another 2% of the

nation’s land (equal to about 10% of cultivated cropland)

was enrolled in the CRP. The CRP removed highly erosive

land out of crop production and established perennial

vegetative cover for 10-15 years. During the decade from

1982 to 1992 there was a net decline in cultivated cropland

of 11%. This net loss of 40.7 million acres resulted from

29.5 million new acres being converted to cultivated

cropland while 70.1 million acres of cultivated cropland

were converted to other uses (Appendix B). Of those 70.1

million acres of converted cropland, 43% was enrolled

into the CRP, 26% was converted to noncultivated cropland, 16% went to pasture, and about 4% went to urban

land.

Noncultivated cropland increased by 4% during the

decade. This shift was the net result of 18.5 million acres

of cultivated cropland being converted to noncultivated

cropland and 14.5 million acres of noncultivated cropland being converted to cultivated cropland. These shifts

may be partially explained by crop rotations that move

land between crop production and hay.

There was a net decline in pasture of about 4% during

the decade, but pasture use was more dynamic than this

net change implies. Nearly 20% of the 1982 pasture land

area was converted to another cover or use by 1992

(Appendix B). Most of the pasture loss went to cropland

(29% cultivated, 15% noncultivated) while 30% of it reverted to forest land. A smaller acreage of pasture was

converted into urban (9%), rangeland (5%), and CRP (5%).

Agricultural land is most abundant in the North with

about 36% of the nation’s total, followed by the South

(31%), Rocky Mountain (28%), and the Pacific Coast

(5.0%) regions (Appendix B). The North has 38% of the

nation’s cropland, followed by the Rocky Mountain (33%),

South (24%), and Pacific Coast (5%) regions. The nation’s

pastureland is greatest in the South (52%), followed by the

North (32%), Rocky Mountain (12%), and Pacific Coast

(4%) regions.

All four regions exhibited declines in cultivated cropland and increases in noncultivated cropland during the

decade. The South lost 17% of its cultivated cropland,

followed by the Pacific Coast (-14%), Rocky Mountain

(-10%), and North (-7%) (Appendix B). Increases in

noncultivated cropland were greatest in the South showing a 12% increase, followed by the Pacific Coast (6%),

North (2%), and Rocky Mountain (1%) regions.

Pastureland increased slightly in the South (+1%) and

Rocky Mountain (+<1%) regions, but declined in the

North (-13%) and Pacific Coast (-6%) regions.

Apart from agricultural land area dynamics, the intensity with which land is managed for crop production also

affects wildlife habitat quality. In general, more intensive

use of agricultural lands as indicated by such attributes as

farm size, nutrient inputs, pesticide use, soil erosion, and

irrigation reduces the quality of wildlife habitats associated with agricultural lands (Allen 1995).

Farm size is an indirect indicator of the quality of

agricultural habitats to wildlife. In order to capture the

economic efficiencies associated with larger farm equipment and new technology, agricultural production has

become concentrated in fewer and larger farms (Committee on Impacts of Emerging Agricultural Trends on Fish

and Wildlife Habitat 1982). From 1940 to 1992 the number

of farms has declined by nearly 75% (from 7 to 1.9 million

farms), while the average size of farms has increased by

nearly 200% (from 160 to 490 acres/farm) (USDA Economic Research Service 1997). The proportion of farms

that are greater than 500 acres has increased at an accelerated pace since about 1960, while the proportion of

farms in the smaller size classes (1 to 49 acres and 50 to 499

acres) has declined. Because of these changes, farms are

now characterized by larger field sizes, reduced crop

diversity, and a loss of small but important wildlife

habitats such as fencerows, hedgerows, field border strips,

wetlands, woodlots, and odd noncultivated areas within

fields (Brady 1988; Warner and Brady 1994). With this

form of agricultural intensification the amount of vertical

and horizontal habitat diversity is reduced, which has

been shown to degrade wildlife habitats in agriculturally

dominated landscapes (Flather and others 1992).

In order to maintain high agricultural productivity,

supplemental nutrient inputs are required on most agricultural lands. Since 1960, the amount of primary nutrient

use (i.e., nitrogen, potash, and phosphate) increased from

7.5 million tons to 23.7 million tons in 1981--an increase of

216% (figure 5) . From 1981 to 1995, the amount of primary

nutrient use has fluctuated around 20 million tons. Although the most recent decade shows constancy in amount

of primary nutrient use, nitrogen applications show evidence of an increasing trend, having reached a maximum

in 1994 of 12.6 million tons. Given that cropland and

pastureland have declined in area since 1982, then the

amount applied to each acre has actually increased, indicating an intensification of agricultural land management.

Pesticides have been the fastest growing input to agricultural production in the last 50 years. Early USDA

benchmark surveys of pesticide use indicated that applications grew from 215 million pounds in 1964 to 572
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999 15

Wildlife Resource Trends in the United States Flather, Brady, and Knowles

million pounds in 1982 (USDA Economic Research Service 1997). It is difficult to interpret these trends since the

amount of pesticides used is a function of acres planted,

the proportion of acres treated, and the application rate

per treated acre. Figure 6 shows the trend in pounds of

active ingredients of pesticide per planted acre from 1964

to 1995. Over that period, application rates for all pesticides has more than doubled.4

 The greatest increases were

observed in herbicides (+415%), other pesticides (+358%),

and fungicides (+55%). The use of insecticides has declined by 57% since 1964 due to the replacement of

organochlorine insecticides with other insecticides that

can be applied at much lower rates (USDA Economic

Research Service 1997:121). Recent trends in insecticide

applications have shown a steady increase from 0.234

pounds of active ingredients per acre planted in 1990 to

0.305 pounds of active ingredients per acre planted in

1995--an increase of 30%.

Irrigation is an agricultural intensification that can

negatively affect aquatic (e.g., reduced instream flows,

reduced water quality) and terrestrial habitats (e.g., increased erosion, increased field salinity). Even though

cropland area has declined during the 1982 to 1992 decade, total acres irrigated has increased slightly from 61.6

million acres to 62.1 million acres (table 6). Irrigated

cropland has increased at the greatest rate in the North

(+14%), where an additional 403,000 acres were irrigated

in 1992 compared to 1982. Minor increases were observed

in the South (+1%), with essentially no change in the

Rocky Mountains. The Pacific Coast region did observe a

net decline in irrigation of 309,000 acres (-2%). Although

there was a net decline in irrigated cropland in the Pacific

Coast, the proportion of cropland that was irrigated

increased by more than 4% (table 6). Nationally, the

proportion of cropland that was irrigated increased from

15% in 1982 to 16% in 1992 (table 6).

Increased soil erosion and resulting sediment deposition has been one of the effects of agricultural intensification throughout most of history. However, increased

awareness on the part of agricultural producers, successful delivery of technical assistance, and recent USDA

incentive programs linked to stewardship are paying off.

In 1982, 73% of the cultivated cropland was experiencing

sheet and rill erosion rates lower than the T-value (i.e., the

tolerable limit) required to maintain productivity. By

1992 that level had increased to nearly 79% of the cultivated cropland (USDA Natural Resources Conservation

Service 1994). Likewise, wind erosion rates on cultivated

cropland in the plains states and other areas subject to

wind erosion have declined. The proportion of cultivated

cropland protected from wind erosion increased from 79

to 84% from 1982 to 1992 (USDA Natural Resources

Conservation Service 1997). These improvements stem

from improved technology applied on the land and the

Figure 5. Trends in commercial fertilizer use among primary

nutrients (nitrogen, potash, and phosphate) from 1960 to

1995 for the United States (USDA Economic Research

Service 1997).

Figure 6. Trends in pesticide use from 1964 to 1995 for the

United States (USDA Economic Research Service 1997).

4 As estimated for selected crops including corn, soybeans,

wheat, cotton, potatoes, other vegetables, citrus fruit, apples,

and other fruits (see USDA Economic Research Service 1997).

1960 1965 1970 1975 1980 1985 1990 1995

Year

0

5

10

15

20

25

Commercial fertilizer use (million tons)

Nitrogen

Phosphate

Potash

Total

1965 1970 1975 1980 1985 1990 1995

Year

0

0.5

1

1.5

2

2.5

3

Pounds of active ingredient per planted acre

Herbicides

Insecticides

Fungicides

Other

pesticides

Total
16 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999

Flather, Brady, and Knowles Wildlife Resource Trends in the United States

Table 7--Comparison of erosion indicators from 1982 to 1992 (USDA Natural Resources Conservation Service 1994). 

Total U.S. North South Rocky Mountain Pacific Coast 

1982 1992 1982 1992 1982 1992 1982 1992 1982 1992 

USLEa

(tons/acre/year) 

4.0 3.1 5.1 3.7 4.5 3.8 2.5 2.0 3.3 2.3 

WEQb

(tons/acre/year) 

3.4 2.4 1.5 1.3 4.2 2.7 5.1 3.7 1.9 2.1 

EIc

< 2 81,400.0 78,645.3 48,440.7 47,329.3 16,690.2 15,665.0 5,422.4 5,058.4 10,846.7 10,592.6 

2 ≤ EI < 5 134,023.7 125,738.6 51,032.2 49,080.4 38,800.6 34,606.8 40,182.4 38,693.0 4,008.5 3,358.4 

5 ≤ EI < 8 80,281.0 72,328.2 18,597.9 17,251.3 20,235.6 16,864.4 38,623.8 35,758.0 2,823.7 2,454.5 

EI ≥ 8 124,847.6 105,238.0 36,170.8 32,067.1 30,920.9 23,742.2 52,460.0 44,987.5 5,295.9 4,441.2 

a

Sheet and rill erosion in tons/acre/year estimated from the Universal Soil Loss Equation (USLE). 

b

Wind erosion in tons/acre/year estimated from the Wind Erosion Equation. Erosion estimates from USLE and WEQ are not 

additive, but apply at different locations within the regions. 

c

EI is the erodibility index estimated from either of the two erosion equations. From the USLE the EI is estimated as: EI=RK(ls)T, 

where R=rainfall factor, K=soil erodibility factor, ls=length and percent slope factors, and T=tolerable soil loss limit. Units displayed 

are acres X 1,000. From the WEQ the EI is estimated as: EI=CI/T, where C is the climatic factor expressed as a percent, and I is 

the soil erodibility factor. Only the higher of the EI(USLE) or EI(WEQ) is reported for any particular location. 

Table 6--Trends in irrigated cropland from 1982 to 1992 (USDA Natural Resources Conservation 

Service 1994). 

Acres of irrigated cropland Proportion of cropland irrigated 

Region 1982 1992 % change 1982 1992 change 

 --------thousand acres------- --------------------percent----------------- 

North 2,809.2 3,212.5 17.2 1.8 2.3 0.5 

South 20,588.2 20,853.6 1.3 19.3 22.9 3.6 

Rocky Mountain 25,818.3 25,839.3 <1 18.9 20.7 1.8 

Pacific Coast 12,438.9 12,129.6 -2.5 54.1 58.2 4.1 

Total U.S. 61,654.6 62,115.0 <1 14.7 16.3 1.6 

conservation provisions of USDA Farm Programs since

1985, including the removal of 34 million acres of eroding

cropland that was enrolled in the CRP.

Other measures of soil erosion that indicate better land

stewardship are shown in table 7. Sheet and rill erosion,

as estimated from the Universal Soil Loss Equation (USLE;

Wischmeier and Smith 1978), has declined nationally and

in all four RPA regions on both cultivated and

noncultivated cropland from 1982 to 1992. In addition,

wind erosion as estimated by the Wind Erosion Equation

(WEQ; USDA Soil Conservation Service 1978) has declined in all regions except the Pacific Coast. Erosion rates

declined between 1982 and 1992 primarily because many

of the cropland acres with elevated erosion rates were

entered into the CRP, removing them from cultivation

and protecting them with perennial vegetation for 10-15

year contracts, beginning in 1986. Another indication of

better stewardship are the acres of cropland with lower

values of the erodibilitiy index (EI) between 1982 and

1992. The EI is computed using the soil, climatic, and

topographic variables from the USLE and WEQ in the

numerator and the T-value in the denominator. The EI

calculated using this procedure does not include the

effect of management practices such as contour farming
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999 17

Wildlife Resource Trends in the United States Flather, Brady, and Knowles

or conservation tillage; therefore it represents an index of

potential erosion based upon natural conditions. The

number of acres in each of the EI categories for cropland

have been reduced since 1982 (table 7). EI values greater

than or equal to 8 are considered to be highly erodible and

those acres declined in all four Assessment regions with

the national decline being 16%—a reduction that exceeds

all other EI categories. Again this is the result of land-use

shifts where the most erodible cropland acreage has been

shifted to other uses, indicating that USDA programs

since 1985 targeted those lands with the greatest potential

for environmental damage.

USDA Farm Programs implemented since 1985 have

had a positive effect on curbing soil erosion and on

managing croplands. About 75-85% of farmers traditionally have participated in USDA commodity support programs (U.S. Department of Agriculture 1986). The particular programs that recently have had the greatest effect

on encouraging conservation and stewardship of croplands include the CRP and the highly erodible land

provisions of the 1985 Food Security Act (i.e., Conservation Compliance and Sodbuster).

The CRP has the greatest potential to directly improve

wildlife habitat associated with agriculture. Participation

in the CRP was greatest in the Rocky Mountain region

with 45% of the nation’s total, followed by the South

(26%), North (24%), and Pacific Coast (5%). Land enrolled

in the CRP has shown local benefits to many wildlife

species, especially grassland nesting birds (Johnson and

Schwartz 1993, Kimmel and others 1992), but the program’s

effect at the regional scale may not be as strong (Brady and

Flather 1998). Although CRP has received much of the

policy attention related to direct wildlife habitat benefits,

other Farm Program provisions also have the potential to

benefit wildlife habitat indirectly.

The highly erodible lands provisions of the 1985 Food

Security Act included the “Sodbuster” and Conservation

Compliance provisions. Sodbuster requires that lands

newly converted to cropland are managed to control soil

erosion within specified levels. Conservation Compliance required that all highly erodible (e.g., EI ≥8) croplands be farmed according to an approved plan that

brings soil erosion losses to within specified acceptable

levels. Both provisions were tied to other USDA programs such that participants in any of those programs

must meet the soil erosion criteria specified in a mutually

agreed upon conservation plan in order to receive USDA

program benefits. The Conservation Compliance provisions will be effective as long as USDA continues to offer

financial incentives for the numerous farm programs, but

will lose effectiveness if USDA reduces program benefits

in the future. Any benefits to wildlife from these programs were largely indirect in that they did not generally

establish habitat as in the CRP (Brady 1988), but soil

erosion was reduced and therefore sediment delivery to

aquatic habitats was also reduced. Additionally, more

careful selection of lands suitable for cultivation occurred

and the conversion of highly erodible rangelands, pastures, and forests was likely reduced. While these provisions and the CRP were generally retained in the 1996

Farm Act, additional programs such as the Wildlife Habitat Incentives Program (WHIP) and the Environmental

Quality Incentives Program (EQIP) will create additional

USDA incentives to manage agricultural lands to benefit

at least some species of wildlife.

Wetland Habitats

Wetlands are characterized by constant or recurrent

shallow inundation, or saturation, at or near the surface

(Committee on Characterization of Wetlands 1995). For

the purposes of classification, Cowardin and others

(1979:3) have specified three diagnostic attributes of wetland habitats of which all wetlands exhibit at least one:

“(1) at least periodically, the land supports predominantly hydrophytes; (2) the substrate is predominantly

undrained hydric soils; and (3) the substrate is nonsoil

and is saturated with water or covered by shallow water

at some time during the growing season of each year.”

Wetland ecosystems are generally very productive and

they are often critical to flood and erosion control, aquifer

recharge, and water purification (Mitsch and Gosselink

1986; Scodari 1997). The inherent productivity of wetlands supports a diversity of wildlife and fish that are

important to commercial fisheries, furbearer harvests,

waterfowl hunting, recreational fishing, and

nonconsumptive outdoor recreation and study.

Despite these values, it was not long ago that Federal

land policies encouraged the conversion of wetlands

(Scodari 1997). During the early settlement period of

America, wetlands were perceived as an impediment to

economic development and up until the mid-1970s, wetland drainage and conversion was an accepted land use

policy (Mitsch and Gosselink 1986). Of the 221 million

acres of wetlands that occurred in the lower 48 states at

the time of Colonial America, only 104 million acres

remained by the mid-1980s (Dahl 1990). A study by

Frayer and others (1983) estimated that the rate of wetland loss was nearly 460,000 acres/year from the mid1950s through the mid-1970s. The annual rate of wetland

loss had declined substantially from the mid-1970s to

mid-1980s to about 260,000 acres/year (Dahl and Johnson

1991).

Agricultural development has been the primary economic force in the conversion of wetlands. Indeed, some

of the most fertile and productive agricultural soils in

such areas as the Corn Belt, Northern Plains, Mississippi
18 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999

Flather, Brady, and Knowles Wildlife Resource Trends in the United States

Table 8--Estimates of wetland area by wetland class from 1982 to 1992 (USDA Natural Resources 

Conservation Service 1994). 

Wetland class 

 Emergent Scrub-shrub 

 Region 1982 1992 Gain/loss 

(% change) 

1982 1992 Gain/loss 

(% change) 

----------------------------------------------thousand acres--------------------------------------------- 

North 8,712.3 8,352.7 -359.6 (-4.1) 5,042.6 4,862.7 -179.9 (-3.6) 

South 11,897.5 11,533.2 -364.3 (-3.1) 1,374.7 1,272.9 -101.8 (-7.4) 

Rocky Mtn. 8,753.0 8,758.3 5.3 (<0.1) 511.6 509.6 -2.0 (-0.4) 

Pacific Coast 1,676.7 1,684.3 7.6 (0.4) 303.2 295.2 -8.0 (-2.6) 

Total U.S. 31,039.5 30,328.5 -711.0 (-2.3) 7,232.1 6,940.4 -291.7 (-4.0) 

Delta, and the Southeastern states were wetlands that

were drained for agricultural production (Brady and

Flather 1994). According to Frayer and others (1983),

conversion of wetlands to cropland production accounted

for 87% of the wetland losses during the period 1954-1974.

From the mid-1970s to mid-1980s, the role of agricultural

development in wetland conversion had diminished to

54% (Dahl and Johnson 1991).

The most recent data on wetland habitat trends come

from the 1992 NRI (USDA Natural Resources Conservation Service 1994). We analyzed wetland trends from

1982-1992 and found that the rate of wetland loss has

continued to decline and that the land use activities

responsible for wetland conversion have shifted. There

was a net loss of nearly 791,000 acres of wetlands over the

period for an average annual loss rate of 79,000 acres/

year (figure 7)—a reduction of nearly 70% in the loss

rate observed between the mid-1970s and mid-1980s.

Among those Assessment regions that had a net loss of

wetlands, the majority of lost wetlands (56%) occurred in

the South, 41% occurred in the North, and the remaining

3% were lost from the Pacific Coast. The Rocky Mountain

region actually had a small, yet statistically nonsignificant, net gain of wetland habitats. Of the wetlands that

were converted, 85% were palustrine (also called inland freshwater wetlands) with the greatest losses of

this type occurring in the South and North. An additional 10% of the lost wetlands were estuarine and were

concentrated in the South, particularly along the Gulf

Coast.

The reduced rate of wetland loss that has occurred in

the last decade was caused, in part, by Federal Programs

designed to conserve and restore wetland habitats (e.g.,

“Swampbuster” or the Wetlands Conservation provisions of recent Farm Acts since 1985). Of particular note

is the Wetlands Reserve Program, which has restored

approximately 665,000 acres of wetlands from 1992

through early-1999.5 Nearly 55% of these restored wetland acres occurred in the South, 26% were in the North,

10% were in the Rocky Mountain region, and the remaining 9% occurred in the Pacific Coast.

Loss of wetlands by wetland class (i.e., the dominant

life form or substrate composition [Cowardin and others

1979]) indicates that wetlands characterized by emergent vegetation accounted for 70% of lost wetlands

while scrub-shrub wetlands accounted for an additional 29% of converted wetlands (table 8). Forested

wetlands actually gained more than 218,000 acres nationwide. When examined regionally, forested wetlands showed varying dynamics. The South lost 51,000

acres of forested wetlands, with much of the loss occurring in the Southeast and Mississippi Delta regions

(Cubbage and Flather 1993). The loss of forested wetlands

in the South was more than offset by a gain of 304,000

acres of forested wetlands in the North. The large increase in forested wetlands in the North is likely due to

successional changes from scrub-shrub to forested wetlands.

Land use activities that have caused the conversion of

wetland habitats have shifted from agricultural to urban

development (figure 7). Based on the 1992 NRI, urban and

built-up land (i.e., urban and suburban areas, residential

5 USDA Natural Resources Conservation Service, Wetlands

Reserve Program data. Report on file at the Rocky Mountain

Research Station.
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999 19

Wildlife Resource Trends in the United States Flather, Brady, and Knowles

Table 8 (Cont'd.) 

Wetland class 

Forested Other Total 

1982 1992 Gain/loss 

(% change) 

1982 1992 Gain/loss 

(% change) 

1982 1992 Gain/loss 

(% change) 

---------------------------------------------------------------------------thousand acres----------------------------------------------------------------------------

23,657.6 23,961.2 303.6 (1.3) 4,531.6 4,438.2 -93.4 (-2.1) 41,944.1 41,614.8 -329.3 (-0.8) 

35,626.1 35,575.2 -50.9 (-0.1) 5,255.6 5,325.9 70.3 (1.3) 54,153.9 53,707.2 -446.7 (-0.8) 

384.9 368.0 -16.9 (-4.4) 3,003.9 3,030.1 26.2 (0.9) 12,653.4 12,666.0 12.6 (<0.1) 

690.8 673.8 -17.0 (-2.5) 823.3 813.5 -9.8 (-1.2) 3,494.0 3,466.8 -27.2 (-0.8) 

60,359.4 60,578.2 218.8 (0.4) 13,614.4 13,607.7 -6.7 (<-0.1) 112,245.4 111,454.8 -790.6 (-0.7) 

developments, industrial sites, roads, railroads, airports,

golf courses, but excluding on-farm structures) were

responsible for 57% of the wetland acres that were converted during the 1982-1992 period. Agricultural development now accounts for only 20% of the wetland conversions nationwide over the 1982-1992 period. The contribution of various land use activities to wetland conversions does vary regionally. Agricultural development

was the most important factor in the Rocky Mountains

(37% of regional wetland area lost) and least important in

the Pacific Coast (10% of regional wetland area lost).

Development associated with urban and built-up areas

was clearly the most important in those regions with

substantial coastal wetlands. Urban development in the

North and South accounted for 63% and 58% of the

wetland conversions, respectively. The prevalence of

wetland losses due to urban development in regions with

a lot of coastal wetlands is consistent with Culliton and

others’ (1990) finding that human population growth in

coastal counties was four times the national average over

the last 50 years.

Because the NRI inventories nonfederal land only,

some caution is required in interpreting these trends.

Some areas that were wetlands in 1982 came under

federal ownership in 1992 and a small amount of federally

owned land in 1982 went into nonfederal wetlands in

1992. We assumed that the wetland status of these areas

was not affected by the change in land ownership and,

therefore, they were not included in our estimates of loss,

gain, or percent change depicted in table 8 and figure 7. Of

the 394,500 acres of wetlands in 1982 that were converted

to federal ownership by 1992, 87% occurred in the South,

7% occurred in the Pacific Coast, with the remainder

being split between the North and Rocky Mountain regions.

Implications of Habitat Trends to Wildlife

National trends in major land use categories (i.e., forest

land, rangeland, and agricultural land) have shown relatively minor changes in total area over the last 50 years.

Although the relative change in area over time has been

small, the absolute number of acres that have shifted

among the various land use activities has been substantial. As we reviewed earlier, the most notable recent land

use shift has been caused by the Conservation Reserve

Program, which retired approximately 36 million acres of

cropland into perennial vegetative cover for 10- to 15-year

contracts. Area changes in minor land use and land cover

classes tended to show greater relative changes over time,

with the 120% increase in urban land from 1945-1992

being particularly noteworthy. The increase in urban land

also has become the primary factor in the continued loss

of wetland habitats nationwide, with 57% of the wetlands

lost between 1982 and 1992 being caused by conversion to

urban and built-up land.

Land use activities fundamentally affect the composition and configuration of wildlife habitats. Therefore, the

trends reviewed above presage the changes in wildlife

populations and harvests that are reviewed in the next

section. Of the land use and land cover changes that we

reviewed earlier, those that are likely to significantly

affect wildlife populations and harvests include the increase in urban and built-up land, the retirement of

cropland acreage into the Conservation Reserve Pro-
20 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999

Flather, Brady, and Knowles Wildlife Resource Trends in the United States

Figure 7. Net changes in wetland acres, and land use factors causing wetland loss from 1982 to 1992 for the United States and

RPA Assessment region (USDA Natural Resources Conservation Service 1994).

gram, changes in forest successional stages (as indicated by forest cover type changes and shifts among

timber size classes), the extensive loss of grassland

habitats, and the continued loss of wetland habitats.

Based on these land use and land cover trends, we

should expect increases in species that tolerate intensive land use activities, increases in species that are

associated with agricultural habitats, decreases in species that are associated with grassland habitats and

earlier successional stages of forest habitats (particularly in the North), and declines in species associated

with wetland habitats (with the possible exception of

species occurring in the northern plains states).

Population and Harvest Trends

The ecosystems within the United States support some

of the most diverse temperate forests, warm deserts, and

shallow-water wetland systems found globally (Ricketts

and others, 1999). Because of the diversity of resident and

common migrant species that occur within the United

States, we address the status and trends of populations

and harvest by major species categories including: big

game, small game, migratory game birds, furbearers,

nongame, and threatened and endangered species. EstiPacific Coast

Rocky Mountain

North

South

National

Agriculture

Miscellaneous

Deep water

Development

Percent loss due to:

19.82

56.68

12.93

10.57

26.17

63.28 4.91

5.64

9.62

48.50

7.93

33.94

36.92

21.53

7.56 33.99

14.92 58.18

18.60

8.30

Other

Palustrine

Total

-800 -600 -400 -200 0

Acres (x1,000)

Other

Palustrine

Total

-500 -400 -300 -200 -100 0 100

Acres (x1,000)

Other

Palustrine

Total

-500 -400 -300 -200 -100 0 100

Acres (x1,000) Other

Palustrine

Total

-500 -400 -300 -200 -100 0 100

Acres (x1,000)

Other

Palustrine

Total

-500 -400 -300 -200 -100 0 100

Acres (x1,000)
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999 21

Wildlife Resource Trends in the United States Flather, Brady, and Knowles

mates of species populations and harvests (not including

poaching) were compiled primarily from data provided

by cooperating state and federal agencies. Because data

sources vary by species categories, the details concerning

source documents and data bases will be discussed within

each species category section. Given the diversity of data

sources that we used, it should not be surprising that data

quality also varied greatly. In some cases, national inventories have been designed to provide statistically based

estimates from which strong inferences on population

size and trend can be made at state, regional, and national

scales. In other cases the estimates are based on the best

judgments of wildlife professionals and more emphasis

should be placed on the direction of the trend rather than

the actual magnitude of the estimates.

Big Game Species

Big game are primarily comprised of large mammal

species that are taken for sport or subsistence. Because of

state agency convention, we also consider the wild turkey

as a big game species. The species comprising big game

were the first to stimulate widespread public interest in

wildlife conservation and many of these species are now

highlighted as wildlife management successes (Thomas

1990). For these reasons, the data from which recent

historical trends could be examined were available over

many states and over long time periods.

We compiled data on big game populations and harvests primarily from cooperating state wildlife agencies.

We sent questionnaires developed cooperatively by the

Forest Service and Natural Resources Conservation Service to state wildlife agency offices through the International Association of Fish and Wildlife Agencies. All

states cooperated and responded to our request for information. The absence of data from certain states resulted

from variation in the distribution of species or the lack of

data for certain years. We included only those states that

provided estimates for 1975 to 1990 (in 5-year intervals),

and 1993 in the trend analysis. The states were also

requested to provide short-term (≈10-year) and longterm (≈50-year) population projections assuming a continuation of the current management direction in each

state. This resulted in state agency population and harvest projections, expressed as a percentage change from

1993 levels to the year 2000 and 2045. We projected

population and harvest estimates by first calculating a

weighted average percentage change for each species.

The 1993 total population or harvest within each state

served as the weights. Our weighted average percentage

change for the year 2000 and 2045 was then applied to the

1993 estimate to project populations and harvests to those

years. Population and harvest data were sufficient to

analyze trends for five species or species groups including pronghorn, elk, deer, black bear, and wild turkey.

Big game populations

Nationally, estimates of big game populations have

increased substantially since 1975 (figure 8). Population

increases have varied by species with wild turkey populations increasing by 211% over the 1975-1993 time period

and pronghorn populations increasing by 56%. The estimated increase in wild turkey populations from state

agency data is supported by the Breeding Bird Survey,

which estimated an average annual increase in wild

turkey detections of 13% from 1985 to 1996.6 Deer populations (including both white-tailed and mule deer) have

undergone the greatest increase with 8.1 million individuals being added to the total population of reporting

states since 1975. Although there have been recent population gains among big game species, the rate of increase

appears to have declined during the 1990s for all species

except elk and black bear. In the 11 states reporting elk

trends, populations have increased by more than 70%. As

noted by Peek (1995), elk now occupy more suitable

habitat and are more numerous than at any time since the

turn of the century. The trend in black bear populations

(+76% in 18 reporting states) is consistent with the findings of Vaughan and Pelton (1995) who found that of 40

states reporting estimates of black bear populations, 27

had increasing trends and only two had declining trends.

In the majority of cases, regional population trends are

qualitatively consistent with national trends. Notable

exceptions to this pattern include deer in the West, wild

turkey in the Rocky Mountain region, and pronghorn in

the South. Deer populations in the Rocky Mountain region have declined by about 11% from 1985 to 1993.

Similar declines have been estimated in the Pacific Coast,

with deer numbers declining by 12% from 1980 to 1993.

Wild turkey populations increased steadily in the Rocky

Mountains through the 1980s, but 1993 estimates indicated that the population in reporting states had declined

by 30% during the early 1990s. The trend in wild turkey

populations in the Rocky Mountains may be an artifact of

the few number of states that reported population estimates for this species. The variability in pronghorn population in the South is also difficult to interpret since this

region has relatively low populations of pronghorn that

inhabit an area on the southeast periphery of the species’

current range.

6 J.R. Sauer, pers. comm., U.S. Geological Survey, Biological

Resources Division, Patuxent Wildlife Research Center, 1997.

Breeding Bird Survey trend analysis. Data on file at the Rocky

Mountain Research Station.
22 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999

Flather, Brady, and Knowles Wildlife Resource Trends in the United States

Because population trends for many big game species

are celebrated as wildlife management successes, and

because big game contribute significantly to rural economies through recreational harvests, it can be difficult to

accept that overabundant populations of some species in

some regions can carry significant economic and ecological costs. Some of the more salient impacts caused by

overabundant populations include increases in transmission of wildlife diseases to humans, direct human injury,

collisions with vehicles or aircraft, and damage to agricultural crops, residential landscaping, and timber (Conover

and others 1995). The overabundance of white-tailed deer

populations has become so prevalent that it will likely

represent one of the more important wildlife management problems during the next decade (Warren 1997).

Despite the significance of these impacts, there have

been few studies that quantified their magnitude nationwide (Conover and others 1995). Romin and Bissonette

(1996) examined deer-vehicle collisions and found that

for 29 states reporting trends, the number of deer killed

has increased an average of 210% per state from the early

1980s through the early 1990s. Much of this increase can

be attributed to vehicle-collision records observed in the

North (224% increase based on data from 18 states).

Increases in the South (168% based on data from 4 states)

and Rocky Mountains (81% based on data from 7 states)

Figure 8. National and regional trends in big game populations for selected species. The number of states that provided historical estimates since 1975, short-term projections, and long-term projections are indicated above the 1993, 2000, and 2045 bar,

respectively. Historical population estimates are summed across those states that provided data. Projections are based on a

weighted average percentage change from 1993 to the year 2000 and 2045 for those states that provided projection estimates.

The average percentage change was then applied to the 1993 population estimate in order to extrapolate a total projected

population for those states that provided historical population estimates. The species group “deer” includes white-tailed deer and

mule deer. (State wildlife agency data. Data on file at the Rocky Mountain Research Station.)

National

North

South

Rocky

Mountain

Pacific

Coast

'75 '80 '85 '90 '93 '00 '45

0

150

300

450

600

750 Thousands

11 10 6

'75 '80 '85 '90 '93 '00 '45

0

4

8

12

16

20

24

28

32 Thousands

1 1 1

'75 '80 '85 '90 '93 '00 '45

0

100

200

300

400

500

600

700 Thousands

8 5 8

'75 '80 '85 '90 '93 '00 '45

0

4

8

12

16

20

24

28

32 Thousands

2

1

Pronghorn Elk Wild turkey Deer Black bear

'75 '80 '85 '90 '93 '00 '45

0

200

400

600

800

Thousands

11

11

10

'75 '80 '85 '90 '93 '00 '45

0

500

1000

1500

2000

2 2 2

'75 '80 '85 '90 '93 '00 '45

0

100

200

300

400

500

600

700 Thousands

2 2 1

'75 '80 '85 '90 '93 '00 '45

0

100

200

300

400

500

600

700 Thousands

7

7

7

'75 '80 '85 '90 '93 '00 '45

0

0.5

1

1.5

2

2.5

3

3.5 Millions

22

21

18

'75 '80 '85 '90 '93 '00 '45

0

0.4

0.8

1.2

1.6

2

2.4 Millions

10 10 10

'75 '80 '85 '90 '93 '00 '45

0

50

100

150

200 Thousands

1 1

'75 '80 '85 '90 '93 '00 '45

0

50

100

150

200 Thousands

3 3 3

'75 '80 '85 '90 '93 '00 '45

0

0.4

0.8

1.2

1.6

2

2.4 Millions

8

7

5

'75'80'85'90'93 '00'45

0

5

10

15

20

25 Millions

36 31 26

'75 '80 '85 '90 '93 '00 '45

0

2

4

6

8

10 Millions

18 15 11

'75 '80 '85 '90 '93 '00 '45

0

2

4

6

8

10 Millions

2 21

'75 '80 '85 '90 '93 '00 '45

0

2

4

6

8

10 Millions

7 7 7

'75 '80 '85 '90 '93 '00 '45

0

2

4

6

8

10 Millions

9 77

'75 '80 '85 '90 '93 '00 '45

0

50

100

150

200 Thousands

18 17 16

'75 '80 '85 '90 '93 '00 '45

0

20

40

60

80 Thousands

8 7 7

'75 '80 '85 '90 '93 '00 '45

0

20

40

60

80 Thousands

4 44

'75 '80 '85 '90 '93 '00 '45

0

20

40

60

80 Thousands

4 4 4

'75 '80 '85 '90 '93 '00 '45

0

20

40

60

80 Thousands

2

2 1

Species

Region
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999 23

Wildlife Resource Trends in the United States Flather, Brady, and Knowles

Table 9--Harvest rates among big game species over time. (State wildlife agency data. 

Data on file at the Rocky Mountain Research Station.) 

Pronghorn Elk Wild Turkey Deer Black Bear 

Year na

rateb

n rate n rate n rate n rate 

1975 15 19.1 14 17.8 37 12.0 46 14.8 23 11.3 

1980 14 15.4 12 18.1 32 14.9 45 14.7 21 10.0 

1985 14 16.5 12 16.0 31 12.2 44 16.7 23 8.5 

1990 11 12.9 10 22.4 25 11.1 37 20.5 21 10.0 

1993 11 19.2 11 20.5 30 12.8 38 21.2 22 10.7 

Mean 

rate 

16.6 19.0 12.5 17.9 10.1 

a

The number (n) of states reporting both population and harvest statistics for a 

given species in a given year. 

b

Harvest rate estimated as the proportion of the population harvested annually. 

were much less than those reported in the North. The

increase in vehicle-caused mortality of deer cannot be

entirely attributed to overabundant populations. Increases

in the number of roads and vehicles is also a factor

contributing to high numbers of deer-vehicle collisions.

The economic impacts associated with deer-vehicle

collisions is not trivial. A recent study by Conover and

others (1995) found that the average repair bill per reported accident was $1,577 (in 1993 dollars), which when

applied to the total number of reported accidents translated into a total annual cost of $1.1 billion. This is a

conservative estimate of the total impact since many

accidents are unreported and these figures do not include

costs associated with human injury and deaths that also

occur with deer-vehicle collisions (Conover and others

1995).

The need to control deer populations is likely reflected

in both the short- and long-term projections of deer

populations provided by state agency personnel (figure

8). Nationally, state agency biologists expect deer numbers to remain constant during the next 10 years and

decline slightly over the next 50 years. The greatest longterm deer population decline is expected in the North

where the overabundance problem is a key management

concern. As with deer, state biologists expect pronghorn

populations to show short-term stability, followed by

slight, long-term declines. Both elk and turkey populations are expected to increase over the next 10 years

followed by declines—trends that are driven primarily by

the expected population patterns in the Rocky Mountain

and Southern regions. Biologists from state wildlife agencies expect that bear populations will remain stable in the

future in all regions except the Pacific Coast where increasing populations are anticipated.

Big game harvests

Manipulation of harvests is an important management

tool for achieving desired population levels of big game

species (Caughley and Sinclair 1994). In addition, big

game hunting expenditures ($9.7 billion in 1996) accounted

for nearly 70% of the total specified expenditures for all

types of hunting (USDI Fish and Wildlife Service and

USDC Bureau of the Census 1997). Because of the management and economic importance of big game, harvest

statistics from state agencies were much more complete

than population statistics.

Over the last 20 years, harvests of common big game

species have tended to parallel population trends (figure 9).

The harvest rate, or the proportion of the population

harvested, has varied from about 10% for black bear to

nearly 20% for elk (table 9). Deer and turkey harvest

trends at the national and regional levels are consistent

with population trends. A total of 47 states provided deer

harvest statistics with nearly 6 million deer harvested in

1993. Harvest rates for deer have averaged about 18%

over the last 20 years, although the rate appears to be

increasing over time. Nearly 90% of deer harvested came

from the North and South regions. Turkey harvests were

reported from 41 states and have increased by more than

190% since 1975. Although harvests have increased, the

harvest rate has remained fairly constant (near 12%). The
24 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999

Flather, Brady, and Knowles Wildlife Resource Trends in the United States

turkey population decline noted in the Rocky Mountain

region does not appear to be an artifact of a small state

sample as the harvest reported by 10 states within the

region indicated an 8% decline during the 1990s.

Harvest trends that deviate from population trends

were observed at the regional level. Elk populations in the

Pacific Coast region have grown slightly from 1980 to

1990, yet harvests over that same period show declines.

Similarly, bear harvests in the Rocky Mountain region

have declined by 33% from 1980 to 1993, while populations have increased. Pronghorn populations in the South

have been somewhat erratic since 1975, yet harvests have

declined consistently and substantially (-61%) since 1980.

There are a number of reasons that may explain the

divergence between big game harvest and population

trends: change in regulations in response to public sentiment about harvest of certain species (e.g., black bear);

reduced access to private lands; or reduced participation

in hunting activities. These factors may also affect the

ability of wildlife managers to control excessive populations of deer in the eastern United States (Warren 1997).

Small Game Species

Species treated as small game typically include resident (native and introduced) game birds and mammals

Figure 9. National and regional trends in big game harvests for selected species. The number of states that provided historical

estimates since 1975, short-term projections, and long-term projections are indicated above the 1993, 2000, and 2045 bar,

respectively. Historical population estimates are summed across those states that provided data. Projections are based on a

weighted average percentage change from 1993 to the year 2000 and 2045 for those states that provided projection estimates.

The average percentage change was then applied to the 1993 population estimate in order to extrapolate a total projected

population for those states that provided historical population estimates. The species group “deer” includes white-tailed deer and

mule deer. (State wildlife agency data. Data on file at the Rocky Mountain Research Station.)

National

North

South

Rocky

Mountain

Pacific

Coast

Pronghorn Elk Wild turkey Deer Black bear

Species

Region

'75 '80 '85 '90 '93 '00 '45

0

40

80

120

160

200 Thousands

14 11 9

'75 '80 '85 '90 '93 '00 '45

0

500

1000

1500

2000

1 11

'75 '80 '85 '90 '93 '00 '45 0

50

100

150

200

12 10 8

'75 '80 '85 '90 '93 '00 '45 0

500

1000

1500

2000

1

Thousands

'75 '80 '85 '90 '93 '00 '45

0

200

400

600

800

1000

1

1

1

'75 '80 '85 '90 '93 '00 '45

0

40

80

120

160

200

240 Thousands

13

12

9

'75 '80 '85 '90 '93 '00 '45

0

10

20

30

40 Thousands

3 2 3

'75 '80 '85 '90 '93 '00 '45

0

50

100

150

200 Thousands

9 6 8

'75 '80 '85 '90 '93 '00 '45

0

100

200

300

400

500

600

700 Thousands

41

32 26

'75 '80 '85 '90 '93 '00 '45

0

50

100

150

200

250

300 Thousands

15

13 12

'75 '80 '85 '90 '93 '00 '45

0

10

20

30

40

50

60

70 Thousands

3 2

'75 '80 '85 '90 '93 '00 '45

0

10

20

30

40

50

60

70 Thousands

10 8

6

'75 '80 '85 '90 '93 '00 '45

0

50

100

150

200

250

300 Thousands

9 13 8

'75 '80 '85 '90 '93 '00 '45

0

2

4

6

8 Millions

47 31 39

'75 '80 '85 '90 '93 '00 '45

0

0.5

1

1.5

2

2.5

3

3.5 Millions

19

17

13

'75 '80 '85 '90 '93 '00 '45

0

200

400

600

800 Thousands

4 42

'75 '80 '85 '90 '93 '00 '45

0

200

400

600

800 Thousands

11 9 8

'75 '80 '85 '90 '93 '00 '45

0

0.5

1

1.5

2

2.5

3

3.5 Millions

13 9

8

'75 '80 '85 '90 '93 '00 '45

0

5

10

15

20

25

30 Thousands

29 20 16

'75 '80 '85 '90 '93 '00 '45

0

2

4

6

8

10

12

14 Thousands

10 7 7

'75 '80 '85 '90 '93 '00 '45

0

2

4

6

8

10

12

14 Thousands

4 42

'75 '80 '85 '90 '93 '00 '45

0

2

4

6

8

10

12

14 Thousands

8

6 4

'75 '80 '85 '90 '93 '00 '45

0

2

4

6

8

10

12

14 Thousands

7

3 3
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999 25

Wildlife Resource Trends in the United States Flather, Brady, and Knowles

that are associated with upland (forest, range, or agricultural) habitats. We compiled population and harvest

statistics, as with big game, from cooperating state wildlife agencies. Questionnaires developed cooperatively by

the Forest Service and Natural Resources Conservation

Service were sent to state wildlife agency offices through

the International Association of Fish and Wildlife Agencies. In addition, we supplemented state agency estimates

of upland game bird populations with relative abundance

data from the North American Breeding Bird Survey (see

Droege [1990] for details about the Breeding Bird Survey).

There is some variation among state wildlife agencies

as to the species that are managed as small game. For the

purposes of this report, we review population and harvest statistics for quail, ring-necked pheasant, grouse,

rabbit, hare, and squirrel. In those cases where state data

were not distinguishable to the species level, we report

trends for species groups that are taxonomically or ecologically similar. The species comprising these groups are

described in table 10.

Small game populations

Because few state wildlife agencies monitor small game

populations, the trends that we review here should be

interpreted carefully. With this caveat in mind, it appears

that species associated with rangeland or agricultural

habitats show evidence of declining populations, while

species associated with forest habitats show mixed trends

over time (figure 10).

Northern bobwhite, prairie grouse, hare, and western

quail populations all show evidence of declines from the

mid-1970s or early 1980s to the early 1990s. Among the

five states that reported trends in bobwhite abundance,

populations have declined by nearly 60% from about

28.5 million birds in 1975 to 12 million birds by 1993.

Substantial declines in prairie grouse (approximately

75%) also occurred from 1975 to 1993 among three states,

all within the Rocky Mountain region. Hare and western

quail populations show evidence of declines, but the

trends are mixed. Hare populations increased from the

mid-1970s to the early 1980s after which they declined

substantially (greater than 70%). Western quail also

showed peak populations in the early 1980s followed by

a nearly 85% decline over the next 10 years. Since 1990,

however, western quail numbers have rebounded by

200% to population levels observed in the mid-1980s.

Two species associated with agricultural habitats that

have shown recent evidence of population increases are

cottontail rabbit and ring-necked pheasant. Both species

showed declines during the 1975 to 1985 decade, followed

by population recovery. Cottontail populations are now

estimated to exceed mid-1970 estimates nationwide, with

the increase being attributed to population growth in the

North. Pheasant populations have shown steady gains

since 1985, due primarily to increases of 45% in the Rocky

Mountain region. Pheasant numbers in the North remain

low relative to state estimates in the early 1970s, although

populations have increased slightly during the 1990s.

Forest associated species including squirrel and forest

grouse show mixed trends among regions. Squirrel numbers show steady but slight gains in the North, declines in

the Rocky Mountains, and declines since 1985 in the

South. Forest grouse populations show a cyclical pattern,

but there does appear to be evidence of a general population decline. Forest grouse population peaks and lows

both decline in all regions where data were available.

Because so few states monitor small game populations

(5 states per species nationwide, on average), data from

the Breeding Bird Survey offer an important comparison

for upland game birds (table 11). In general, trends from

the Breeding Bird Survey were consistent with state

agency population trends. Northern bobwhite relative

abundance has declined significantly (P < 0.05) nationwide, in the North, and in the South. Nationwide, bobwhite have declined by 2.5% per year from 1966 to 1996,

and have declined at an even greater rate since 1985 (-

4.4% per year). Scaled quail show a similar pattern,

declining by 3.4% per year since 1966 and declining by 5%

per year since 1985. Ring-necked pheasant trends over the

long-term differ dramatically from short-term trends.

Over the 30-year period from 1966 to 1996, pheasants

have shown significant declines of 1% per year. Since

1985, however, pheasant abundance has actually increased

by 1.3% per year. The only other upland game species

showing significant long-term declines is the blue grouse.

Species that have shown significant population declines

since 1985 include the gray and chukar partridge. No

upland game bird has shown significant long-term population increases, but the California quail and greater

Table 10—Definition of small game species groups.

Group name Species

Cottontail Species of the genus Sylvilagus

Hare Species of the genus Lepus

Squirrel Species of the genus Sciurus and red

squirrel

Forest grouse Ruffed grouse, spruce grouse, blue grouse

Prairie grouse Greater prairie-chicken, lesser prairiechicken, sharp-tailed grouse, sage grouse

Western quail Montezuma quail, scaled quail, Gambel’s

quail, California quail, mountain quail
26 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999

Flather, Brady, and Knowles Wildlife Resource Trends in the United States

Figure 10. National and regional trends in small game populations for selected species groups. The number of states that

provided to be consistent with Figures 8 and 9 historical estimates since 1975, short-term projections, and long-term projections

are indicated above the 1993, 2000, and 2045 bar, respectively. Historical population estimates are summed across those

states that provided data. Projections are based on a weighted average percentage change from 1993 to the year 2000 and

2045 for those states that provided projection estimates. The average percentage change was then applied to the 1993 population estimate in order to extrapolate a total projected population for those states that provided historical population estimates.

(State wildlife agency data. Data on file at the Rocky Mountain Research Station.) Note that no states from the Pacific Coast

region provided historical small game population estimates.

prairie-chicken, along with ring-necked pheasant, have

shown significant increases since 1985.

Factors affecting small game populations include

weather, predation, and habitat quality. Given the reproductive potential of most small game species, increased

predation in the absence of habitat degradation is unlikely to be responsible for declining trends, and populations are generally capable of recovering from declines

attributable to inclement weather. Consequently, detectable abundance trends are likely habitat related (Edwards

and others 1981). Brady and others (1998) examined the

relations between land use and land cover and northern

bobwhite abundance over the geographic range of the

bird. They found that bobwhite abundance was generally

higher in those areas less intensively used by agriculture.

Areas with moderate physiographic relief and greater

habitat diversity tended to support more bobwhite than

did areas supporting intensive agriculture—findings that

are consistent with Brennan’s (1991) review of bobwhite

declines.

Given the conversion of about 36 million acres of

highly erodible cropland to perennial vegetation cover

under the CRP, one might expect a short-term increase in

bobwhite abundance in response to this program. We

found no evidence for a positive bobwhite population

response to the CRP. As noted earlier, bobwhite abundance has actually declined at a greater rate since the CRP

(see 1985-1996 abundance trends in table 11) than over the

last 30 years. The lack of a positive bobwhite population

response to the CRP is likely due to the fact that bobwhite

select for early stages of secondary succession characterized by perennial weeds and early woody shrub developNational

North

South

Rocky

Mountain

Hare

Ring-necked

pheasant Squirrel Cottontail

Species

Region

'75 '80 '85 '90 '93 '00 '45

0

10

20

30

40 Millions

4

4 4

'75 '80 '85 '90 '93 '00 '45

0

5

10

15

20

25

30

35 Millions

1 11

'75 '80 '85 '90 '93 '00 '45

0

5

10

15

20

25

30

35 Millions

3 3

3

'75 '80 '85 '90 '93 '00 '45

0

2

4

6

8

10

12

14 Millions

8 5 6

'75 '80 '85 '90 '93 '00 '45

0

2

4

6

8

10 Millions

4 43

'75 '80 '85 '90 '93 '00 '45

0

2

4

6

8

10 Millions

4

2

3

'75 '80 '85 '90 '93 '00 '45

0

10

20

30

40 Millions

6 4 5

'75 '80 '85 '90 '93 '00 '45

0

5

10

15

20

25 Millions

3 3 2

'75 '80 '85 '90 '93 '00 '45

0

300

600

900

1200

1500 Thousands

1 11

'75 '80 '85 '90 '93 '00 '45

0

5

10

15

20

25 Millions

2 21

'75 '80 '85 '90 '93 '00 '45

0

5

10

15

20

25

30

35 Millions

6 6 5

'75 '80 '85 '90 '93 '00 '45

0

4

8

12

16

20

24

28 Millions

2 22

'75 '80 '85 '90 '93 '00 '45

0

4

8

12

16

20

24

28 Millions

2 2 1

'75 '80 '85 '90 '93 '00 '45

0

4

8

12

16

20

24

28 Millions

2 22
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999 27

Wildlife Resource Trends in the United States Flather, Brady, and Knowles

Figure 10. (Cont’d.)

Table 11—Long-term (1966-1996) and short-term (1985-1996) population trends in upland game birds based on species

observed on ≥ 15 routes (J.R. Sauer, pers. comm., U.S. Geological Survey, Biological Resources Division, Patuxent Wildlife

Research Center, 1997).

Total U.S. North South Rocky Mountain Pacific Coast

1966-1996 1985-1996 1966-1996 1985-1996 1966-1996 1985-1996 1966-1996 1985-1996 1966-1996 1985-1996

Species Trenda P-valueb Trend P-value Trend P-value Trend P-value Trend P-value Trend P-value Trend P-value Trend P-value Trend P-value Trend P-value

Gray partridge 0.8 0.55 -6.1 <.01 1.3 0.58 -7.9 <.01 0.4 0.76 -5.6 0.01

Chukar -5.8 0.10 -9.4 0.04 -6.2 0.08 -8.5 0.11

Northern bobwhite -2.5 <.01 -4.4 <.01 -2.8 <.01 -2.6 <.01 -2.6 <.01 -5.6 <.01 -0.8 0.17 0.1 0.90

Mountain quail 1.5 0.14 1.6 0.39 1.5 0.15 1.6 0.38

Scaled quail -3.4 <.01 -5.0 <.01 -3.9 <.01 -6.8 <.01 -2.1 0.07 -3.7 0.16

California quail 0.9 0.27 4.9 <.01 0.8 0.29 4.7 <.01

Gambel’s quail 1.0 0.14 -0.1 0.97 1.3 0.09 0.5 0.83 -0.9 0.78 -2.4 0.61

Blue grouse -3.4 0.02 -1.9 0.62 -3.3 0.05 -0.7 0.87

Ruffed grouse -0.8 0.56 2.1 0.64 0.1 0.97 6.6 0.15 -2.3 0.60 -14.4 0.19

Greater prairie-chicken 5.0 0.50 20.2 <.01

Sharp-tailed grouse 3.0 0.14 2.2 0.67 3.2 0.15 2.5 0.64

Sage grouse 1.7 0.55 -17.0 0.09 1.6 0.57 -16.9 0.10

Ring-necked pheasant -1.0 0.02 1.3 0.07 -2.0 0.02 1.7 0.02 0.6 1.76 -4.0 0.02 -0.2 0.69 1.4 0.28 -0.9 0.38 0.1 0.94

aTrends are estimated using the route-regression method (Geissler and Sauer 1990). Regional trends are estimated as a weighted average of trends over individual routes using the

estimating equations estimator (Link and Sauer 1994).

bThe probability that the trend is equal to zero. Trends with P-values > 0.10 are not considered to be significantly different from zero.

National

North

South

Rocky

Mountain

Western quail Prairie grouse

Northern

bobwhite Forest grouse

Species

Region

'75 '80 '85 '90 '93 '00 '45

0

400

800

1200

1600 Thousands

2 22

'75 '80 '85 '90 '93 '00 '45

0

200

400

600

800

1000

1200

1400

1600 Thousands

2 22

'75 '80 '85 '90 '93 '00 '45

0

0.5

1

1.5

2 Millions

3 33

'75 '80 '85 '90 '93 '00 '45

0

0.5

1

1.5

2 Millions

3 33

'75 '80 '85 '90 '93 '00 '45

0

5

10

15

20

25

30 Millions

5 43

'75 '80 '85 '90 '93 '00 '45

0

1

2

3

4

5 Millions

1 11

'75 '80 '85 '90 '93 '00 '45

0

50

100

150

200

250 Thousands

1 1 1

'75 '80 '85 '90 '93 '00 '45

0

5

10

15

20

25 Millions

3 2 1

'75 '80 '85 '90 '93 '00 '45

0

1

2

3

4

5

6

7

8 Millions

9 8 6

'75 '80 '85 '90 '93 '00 '45

0

1

2

3

4

5

6 Millions

6 54

'75 '80 '85 '90 '93 '00 '45

0

50

100

150

200

250

300

350 Thousands

2 22

'75 '80 '85 '90 '93 '00 '45

0

1

2

3

4

5

6 Millions

1 1
28 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999

Flather, Brady, and Knowles Wildlife Resource Trends in the United States

Figure 11. National and regional trends in small game harvests for selected species groups. The number of states that provided

to be consistent with figures 8 and 9 historical estimates since 1975, short-term projections, and long-term projections are

indicated above the 1993, 2000, and 2045 bar, respectively. Historical population estimates are summed across those states

that provided data. Projections are based on a weighted average percentage change from 1993 to the year 2000 and 2045 for

those states that provided projection estimates. The average percentage change was then applied to the 1993 population

estimate in order to extrapolate a total projected population for those states that provided historical population estimates (State

wildlife agency data. Data on file at the Rocky Mountain Research Station).

ment (Klimstra and Roseberry 1975). Habitats with such

characteristics have yet to develop on most CRP lands.

The recent population recovery of pheasants does appear

to be related to the CRP. For nesting, pheasants select for

the type of grassland cover that is found in abundance on

most CRP plots. Both the Breeding Bird Survey and state

agency results reviewed here provide evidence that the

CRP has had a regional and national affect on recent

increases in ring-necked pheasant abundance.

State agency projections of small game populations

indicate only minor changes in population (figure 10). For

most species, expected future changes in small game

abundance are less than 10% from 1993 estimates. Forest

grouse species, western quail, and squirrel populations are

expected to remain stable in the future. Hare and cottontail

populations are expected to increase over the next 50 years.

State biologists expect prairie grouse, northern bobwhite,

and ring-necked pheasant populations to decline. Given

recent historical trends (i.e., since 1990), the projected

decline in pheasant numbers is somewhat surprising and

may reflect biologists’ perceptions that CRP lands will be

brought back into agricultural production in the future.

National

North

South

Rocky

Mountain

Pacific

Coast

Hare

Ring-necked

pheasant Squirrel Cottontail

Species

Region

'75 '80 '85 '90 '93 '00 '45

0

0.5

1

1.5

2

2.5 Millions

10

8 6

'75 '80 '85 '90 '93 '00 '45

0

200

400

600

800

1000

1200 Thousands

5

4 4

'75 '80 '85 '90 '93 '00 '45

0

200

400

600

800

1000

1200 Thousands

1 1

'75 '80 '85 '90 '93 '00 '45

0

20

40

60

80

100

120 Thousands

4

3 2

'75 '80 '85 '90 '93 '00 '45

0

2

4

6

8

10

12 Millions

28 21 15

'75 '80 '85 '90 '93 '00 '45

0

1

2

3

4

5

6 Millions

12

9 8

'75 '80 '85 '90 '93 '00 '45

0

1

2

3

4

5

6 Millions

2 2

'75 '80 '85 '90 '93 '00 '45

0

1

2

3

4

5

6 Millions

11 10 7

'75 '80 '85 '90 '93 '00 '45

0

40

80

120

160 Thousands

2

'75 '80 '85 '90 '93 '00 '45

0

10

20

30

40 Millions

28 21 18

'75 '80 '85 '90 '93 '00 '45

0

5

10

15

20

25 Millions

11 9 9

'75 '80 '85 '90 '93 '00 '45

0

100

200

300

400

500

600

700 Thousands

1 1

'75 '80 '85 '90 '93 '00 '45

0

100

200

300

400

500

600

700 Thousands

6 4

4

'75 '80 '85 '90 '93 '00 '45

0

5

10

15

20

25 Millions

10 7 5

'75 '80 '85 '90 '93 '00 '45

0

5

10

15

20

25

30

35 Millions

29 22 17

'75 '80 '85 '90 '93 '00 '45

0

5

10

15

20 Millions

11 9 8

'75 '80 '85 '90 '93 '00 '45

0

0.5

1

1.5

2 Millions

1 1

'75 '80 '85 '90 '93 '00 '45

0

0.5

1

1.5

2 Millions

8 5

4

'75 '80 '85 '90 '93 '00 '45

0

5

10

15

20 Millions

9 75
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999 29

Wildlife Resource Trends in the United States Flather, Brady, and Knowles

Small game harvests

Many more states were able to provide historical trends

in small game harvest (21 states per species nationwide,

on average) compared to population estimates. Based on

data from states that provided both population and harvest

estimates, about 15 to 20% of the small game population

is harvested each year—ranging from a low of about 3%

for hare, to a high of 31% for ring-necked pheasant (table

12). Because so few states provided both population and

harvest estimates, the relation between harvest and population trends is difficult to estimate. Harvest trends that

deviate from population trends could: (1) reflect a more

representative sample of states from which to estimate

harvest, or (2) may reflect changes in the number of hunters

that are actually pursuing small game for reasons independent of population status (e.g., limited access to private land that permits hunting). For these reasons, comparisons of harvest and population trends must be interpreted cautiously.

Northern bobwhite, ring-necked pheasant, hare, and

forest grouse had harvest trends that were qualitatively

similar to population trends (figure 11). Among the 25

states providing harvest data on northern bobwhite, total

annual harvest has declined by more than 50% from 1975

to 1993. The greatest decline occurred in the South where

the number of bobwhite annually harvested in nine states

declined from nearly 17 million in 1975 to just over 6

million in 1993. There is concern that if current population

trends continue, the opportunity to hunt bobwhite across

much of the bird’s range could be lost in the near future

(Brennan 1991). Although pheasant harvests have declined

in the last 20 years, the trend since 1985 shows increasing

numbers of pheasants being taken by small game hunters.

This pattern is particularly evident in the Rocky Mountain region where CRP lands are concentrated. Although

Figure 11. (Cont’d.)

National

North

South

Rocky

Mountain

Pacific

Coast

Western quail Prairie grouse

Northern

Bobwhite Forest grouse

Species

Region

'75 '80 '85 '90 '93 '00 '45

0

0.5

1

1.5

2 Millions

6 4 4

'75 '80 '85 '90 '93 '00 '45

0

50

100

150

200

250

300

350 Thousands

1

'75 '80 '85 '90 '93 '00 '45

0

0.5

1

1.5

2 Millions

5 44

'75 '80 '85 '90 '93 '00 '45

0

100

200

300

400

500

600 Thousands

15 11 8

'75 '80 '85 '90 '93 '00 '45

0

10

20

30

40

50

60 Thousands

1

1 1

'75 '80 '85 '90 '93 '00 '45

0

2

4

6

8 Thousands

3 1

'75 '80 '85 '90 '93 '00 '45

0

100

200

300

400

500

600 Thousands

10 9 7

'75 '80 '85 '90 '93 '00 '45

0

2

4

6

8 Thousands

1

'75 '80 '85 '90 '93 '00 '45

0

5

10

15

20

25

30 Millions

25 14 20

'75 '80 '85 '90 '93 '00 '45

0

3

6

9

12

15

18 Millions

9 7 6

'75 '80 '85 '90 '93 '00 '45

0

3

6

9

12

15

18 Millions

2 2

'75 '80 '85 '90 '93 '00 '45

0

3

6

9

12

15

18 Millions

5 5 4

'75 '80 '85 '90 '93 '00 '45

0

3

6

9

12

15

18 Millions

9 6

4

'75 '80 '85 '90 '93 '00 '45

0

1

2

3

4

5

6 Millions

26 21 16

'75 '80 '85 '90 '93 '00 '45

0

1

2

3

4

5 Millions

10

9

9

'75 '80 '85 '90 '93 '00 '45

0

100

200

300

400

500

600

700 Thousands

3 2

'75 '80 '85 '90 '93 '00 '45

0

100

200

300

400

500

600

700 Thousands

10 8 6

'75 '80 '85 '90 '93 '00 '45

0

100

200

300

400

500

600

700 Thousands

3 2

1
30 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999

Flather, Brady, and Knowles Wildlife Resource Trends in the United States

 Table 12--Harvest rate among small game species over time. (State wildlife agency data. Data on file at the Rocky Mountain 

 Research Station.) 

Hare 

Ring-necked 

pheasant Squirrel Cottontail 

Western 

quail 

Prairie 

grouse 

Northern 

bobwhite 

Forest 

grouse 

Year na

rateb

n rate n rate n rate n rate n rate n rate n rate 

1975 8 5.1 22 34.9 16 20.4 17 17.6 3 9.0 11 13.8 20 21.4 17 18.9 

1980 4 1.5 9 29.6 8 27.9 7 17.3 2 10.3 2 13.1 4 18.5 8 38.7 

1985 5 2.4 12 37.0 12 22.1 11 21.0 2 10.2 5 16.9 9 19.4 10 25.5 

1990 3 2.0 7 26.1 7 23.0 8 11.5 2 12.5 2 12.0 6 20.8 8 45.7 

1993 4 1.8 10 25.7 7 19.6 8 10.6 3 11.7 4 14.0 7 23.0 10 29.3 

Mean 

rate 

2.8 31.0 22.1 16.2 10.3 14.0 20.7 27.8 

a

The number (n) of states reporting both population and harvest for a given species in a given year. 

b

Harvest rate estimated as the proportion of the population harvested annually. 

relatively few pheasants are harvested in the South, harvests have increased consistently since 1975. Conversely,

pheasant harvests in the Pacific Coast have declined by

70% since 1980. Hare harvests declined abruptly between

1980 and 1985, a pattern that was observed in both the

North and Pacific Coast regions. Forest grouse harvests

paralleled the cyclical pattern that was observed in the

population data—a pattern that is driven by harvest

trends in the North. The Pacific Coast and Rocky Mountain

regions show consistent declines in forest grouse harvests

with the exception of the most recent period in the Rocky

Mountain region when harvests have increased slightly.

Harvest and population trends for cottontail, squirrel,

prairie grouse, and western quail differed (compare figures 10 and 11). While cottontail and squirrel populations

were somewhat stable over the last 20 years, annual

harvests of these species groups have declined nationally

and regionally. Over this period, cottontail and squirrel

harvests have declined by nearly 60 and 40%, respectively. In both species groups, the national harvest trend

was dominated by the pattern that has occurred in the

eastern regions. Prairie grouse and western quail harvests also differ from their respective population trends

by expressing a cyclical pattern that was not evident in the

abundance estimates. The cycles in the harvest data notwithstanding, harvests of these species groups do appear

to be declining over the last 20 years.

There are some notable differences between harvest

and population projections among small game species as

well (compare figures 10 and 11). Whereas state agencies

expect pheasant populations to decline in the long-term,

pheasant harvests are expected to increase over the same

projection period. A similar difference was observed with

prairie grouse harvests, which state agencies expect to

increase over the next 50 years while populations are

projected to decline. Conversely, cottontail harvests are

expected to decline nationally even though populations

are expected to remain stable or increase slightly.

Migratory Game Bird Species

Federal authority to conserve and manage migratory

birds is rooted in a series of statutes that were passed in

the early 1900s (Migratory Bird Act of 1913, Migratory

Bird Treaty Act of 1918, Migratory Bird Conservation Act

of 1929). These early international agreements were with

Great Britain on behalf of Canada, with subsequent treaties established with Mexico (1936), Japan (1972), and the

Soviet Union (1976) (Chandler 1985). The primary objective of these treaties is the protection and conservation of

migratory bird populations. Harvesting of migratory

birds in a manner that is consistent with protection is a

secondary objective. The long history of migratory bird

management in North America that was initiated by these

historic agreements has resulted in the development of,

perhaps, the premier monitoring system for continentally

distributed species in the world (Nichols and others

1995). Consequently, population and harvest estimates

are among the most extensive (in time and geographically) and the most reliable for resource planning.

“Migratory game birds” refers to a collection of species

that include waterfowl (ducks, geese, and swans) and

webless migratory species including mourning dove and

woodcock. Population and harvest trends come primarily from annual reports published by the U.S. Fish and

Wildlife Service and from the North American Waterfowl

Plan (U.S. Department of the Interior, Environment

Canada, and Secretaria de Desarrollo Social México 1994).
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999 31

Wildlife Resource Trends in the United States Flather, Brady, and Knowles

Duck populations

The status of duck populations varies among species,

but trends do suggest substantial increases in duck abundance for many species over recent years (figure 12). The

1996 estimate of 37.5 million ducks is 16% higher than the

long-term average (USDI Fish and Wildlife Service and

Canadian Wildlife Service 1996) and is approaching population levels that have not been observed since the early

1970s and late 1950s. These trends contrast sharply with

those reviewed in the previous RPA Assessment (Flather

and Hoekstra 1989), which showed declining trends overall and a record low population of ducks estimated in 1985.

The recent increase in duck populations is likely a

function of many factors and it has been difficult to draw

strong conclusions regarding cause-and-effect because of

the retrospective nature of past studies (Nichols and

others 1995). One factor that appears to play an important

role in explaining yearly variation in duck numbers is the

number of small wetland habitats early in the breeding

season. The increasing trend in wetland habitats observed during the 1990s due to unusually wet conditions

corresponds to a period of rapid population growth in

ducks (USDI Fish and Wildlife Service and Canadian

Wildlife Service 1996). CRP acreage in the northern Great

Plains of the U.S. also provided additional nesting cover.

Populations of the 10 principal duck species indicated

that many species have increased to the point where they

exceed their long-term average (USDI Fish and Wildlife

Service and Canadian Wildlife Service 1996). Mallard,

green-winged teal, and redhead had breeding populations well above their long-term means in 1996. Furthermore, record numbers of blue-winged teal, gadwall, northern shoveler, and canvasback were also observed in 1996.

Species remaining below their long-term mean include

the American wigeon, scaup, and northern pintail. Northern pintail breeding populations are particularly troubling as they have declined from a high of about 10 million

birds in the mid-1950s to 2.7 million birds in 1996. Because

pintails have early nest initiation dates, Beauchamp and

others (1996) have hypothesized that pintails, when compared to other species, may be disproportionately exposed to increased predation and nest destruction from

farm practices, especially early spring plowing.

For the purposes of planning, duck population projections are discussed in terms of long-term management

goals rather than predicted population levels. The North

American Waterfowl Plan (U.S. Department of the Interior, Environment Canada, and Secretaria de Desarrollo

Social México 1994) specifies an overall goal of 62 million

Figure 12. Trends in duck populations from 1965 to 1996

(USDI Fish and Wildlife Service and Canadian Wildlife

Service 1996).

Figure 13. The relation between current (1996) duck populations (CP) and population objectives (PO) for the year 2001

for the 10 principal duck species established by the North

American Waterfowl Plan. Population estimates at the top of

each bar are in thousands of ducks. The y-axis reflects the

degree (measured as a percentage) to which current

populations meet population objectives (U.S. Department of

the Interior, Environment Canada, and Secretaria de

Desarrollo Social México 1994; USDI Fish and Wildlife

Service and Canadian Wildlife Service 1996).

1965 1970 1975 1980 1985 1990 1995

Year

0

10

20

30

40

50

Population (millions)

0

50

100

150

200

250

Percent of goal

Mallard

Pintail

Gadwall

Wigeon

Greenwinged

teal Bluewinged

teal

Shoveler

Redhead

Canvasback

Scaup

CP=7941

PO=8100

CP=2984

PO=1500

CP=2273

PO=3000

CP=2459

PO=1800

CP=6416

PO=4700

CP=2736

PO=5600

CP=834

PO=640

CP=3449

PO=2000

CP=849

PO=540

CP=4250

PO=6300
32 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999

Flather, Brady, and Knowles Wildlife Resource Trends in the United States

breeding ducks under average environmental conditions.

The baseline reference period for establishing this goal

was the mean estimated during the 1970-1979 period

based on the observation that duck numbers during the

1970s generally met the needs of all users. Based on the

goals established for each species, the 1996 population

estimates exceeded those goals for 6 of the 10 principal

duck species (figure 13 on previous page). Only the

pintail, American wigeon, and scaup remain below population objectives. Mallard populations essentially meet

the breeding population objectives for this species.

Duck harvests

Management of duck populations through the annual

establishment of harvest regulations has been a key federal activity directed at ensuring healthy duck populations. Early in the history of migratory game bird management, surveys and band returns indicated that waterfowl

populations followed four major flyways as they migrated from their breeding to wintering habitats (Lincoln

1935). The four flyways are identified by the major northsouth water courses and include the Atlantic, Mississippi,

Central, and Pacific flyways. Because waterfowl have

long been managed according to flyways, harvest trends

will be reviewed according to administrative flyway

boundaries rather than by RPA Assessment regions.

National duck harvests since the early 1960s do track

duck population estimates closely (figure 14). After increasing substantially in the 1960s, harvests remained

relatively stable through the 1970s when an average of

13.5 million ducks were harvested annually. During the

1980s, harvests underwent a near monotonic decline until

1988 when the total duck harvest was 4.7 million birds.

Figure 14. Trends in duck harvests from 1965 to 1995 by administrative flyway (P. Padding, pers. comm., USDI Fish and Wildlife

Service, Office of Migratory Bird Management, 1996).

Pacific

Central Mississippi Atlantic

National:

'65 '70 '75 '80 '85 '90 '95

Year

0

2

4

6

8

10

12

14

16 Millions

'65 '70 '75 '80 '85 '90 '95

Year

0

1

2

3

4

5

6

7 Millions

'65 '70 '75 '80 '85 '90 '95

Year

0

1

2

3

4

5

6

7 Millions

'65 '70 '75 '80 '85 '90 '95

Year

0

1

2

3

4

5

6

7 Millions

'65 '70 '75 '80 '85 '90 '95

Year

0

1

2

3

4

5

6

7 Millions
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999 33

Wildlife Resource Trends in the United States Flather, Brady, and Knowles

Now that population numbers are more favorable, harvests have increased to levels observed during the 1970s.

The 62% increase in duck harvests from 1994 to 1995 was

the greatest annual increase on record.

Duck harvests by flyway show no qualitative deviation

from the noted national trends. Over the last 25 years, 41%

of the national harvest was taken in the Mississippi

flyway, followed by the Pacific (27%), Central (17%), and

Atlantic (15%). All four flyways show a pattern of high

harvests during the 1970s, followed by substantial declines through much of the 1980s, and substantial harvest

increases during the 1990s. Duck harvests in the Mississippi flyway had the greatest increases from 1988 to 1995

(nearly a 260% gain), with 1995 being a record duck

harvest of 6.6 million birds.

Goose and swan populations

Species comprising this group of migratory game birds

include Canada geese, snow geese, Ross’ geese, greater

white-fronted geese, brant, and tundra swans. Because

most geese and swans breed outside of the area that has

been traditionally surveyed to estimate breeding waterfowl populations, most population estimates are derived

from surveys conducted on migration and wintering

areas (USDI Fish and Wildlife Service and Canadian

Wildlife Service 1996). Of the 29 populations of geese and

swans that are monitored with these surveys, 11 have

shown significant increasing trends in overall numbers

over the last 10 years, 12 have had stable populations, two

populations have declined, and four have unreliable trend

data. Consequently, nearly 80% of goose and swan populations are increasing or stable. The two declining populations are both Canada geese—the Atlantic population

and the dusky Canada goose. All other populations of

Canada geese have increasing or stable trends (figure 15),

and Canada geese are likely more abundant now than

they ever have been in the past (Rusch and others 1995).

Because of the high variability in tundra swan population

estimates, both the Eastern and Western populations

show no detectable trend (figure 16). During the 1990s,

tundra swan population estimates averaged 88,000 for

Eastern populations and 67,000 for Western populations.

Figure 15. Trends in Canada goose population indices of abundance (in thousands) from 1969 to 1995. Acronyms are defined

as follows: MVP=Mississippi Valley Population, SGPP=Shortgrass Prairie Population, AFRP=Atlantic Flyway Resident Population, EPP=Eastern Prairie Population, WPP/GPP=Western Prairie Population/Great Plains Population, MFRP=Mississippi Flyway

Resident Population, Cackling=Cackling Canada goose, RMP=Rocky Mountain Population, Dusky=Dusky Canada goose,

TGPP=Tallgrass Prairie Population, HLP=Hi-line Population, AP=Atlantic Population, SJBP=Southern James Bay Population

(USDI Fish and Wildlife Service and Canadian Wildlife Service 1996).

1968 1972 1976 1980 1984 1988 1992 1996

Year

0

200

400

600

800

1000

Population indices (thousands)

Population indices (thousands) Population indices (thousands)Population indices (thousands)

AFRP

MVP

SGPP

1968 1972 1976 1980 1984 1988 1992 1996

Year

0

100

200

300

400

500

WPP/GPP

EPP

MFRP

1968 1972 1976 1980 1984 1988 1992 1996

Year

0

50

100

150

200

250

300

350

AP

SJBP

HLP

1968 1972 1976 1980 1984 1988 1992 1996

Year

0

50

100

150

200

RMP

Dusky

Cackling

TGPP
34 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999

Flather, Brady, and Knowles Wildlife Resource Trends in the United States

Of the 29 goose and swan populations that are monitored, 28 have population goals specified in the North

American Waterfowl Management Plan (U.S. Department of the Interior, Environment Canada, and Secretaria

de Desarrollo Social México 1994). A total of 12 populations are at, or exceed, the population goals specified in

the plan, and several populations exceed the goals by

greater than 50% (Shortgrass Prairie and Rocky Mountain

populations of Canada geese, Midcontinent population

of lesser snow geese, Ross’ goose, and the Eastern

Midcontinent population of White-fronted geese).

Recent population increases in many goose populations, however, cannot always be interpreted as a favorable resource situation. As reviewed by Ankney (1996),

there is growing evidence that some populations exceed

that which is acceptable on biological, esthetic, or economic criteria. One of the factors contributing to these

burgeoning populations is agricultural activities that provide wintering geese with an abundance of waste grain in

proximity to human-caused open water habitats (Rusch

and others 1995). Increased survivorship over the winter

leads to increasing numbers of birds on breeding colonies,

which is causing severe breeding habitat degradation in

some areas (Ankney 1996).

Goose and swan harvests

Record numbers of geese have been harvested nationally for three consecutive years starting in 1993, reaching

2.4 million birds by 1995 (figure 17, see facing page). The

national trend is driven primarily by the pattern of goose

harvests in the Central and Mississippi Flyways, which

accounted for 80% of the birds harvested in 1995. Because

of the dominating influence of harvests in the interior of

the country, the national trend masks the pattern of

harvests in the Pacific and Atlantic Flyways. Harvests of

geese in the Pacific Flyway have remained fairly stable

since the early 1970s. Conversely, goose harvests in the

Atlantic Flyway have been declining since the mid-1980s.

After reaching a peak harvest of about 550,000 birds in

1983, goose harvests in the Atlantic Flyway have declined

to nearly 180,000 birds in 1995. The trend in the Atlantic

Flyway harvests is a significant departure from the trend

observed in the last RPA Assessment (Flather and Hoekstra

1989), which indicated substantial increases in goose

harvests through the mid-1980s.

The harvest trends for tundra swan (figure 18) show a

pattern that is not expected given the population status of

this species. Both the eastern and western populations of

tundra swans have shown relatively stable, although

variable, abundance over the last decade and their populations either exceed or meet population goals set in the

North American Waterfowl Plan. Despite this stability,

the harvest of eastern tundra swans has increased substantially (from 34 birds in 1983 to more than 5,000 birds

in 1994) from the mid-1980s through the 1990s. Harvests

of the western population have declined by about 50%

when one compares a 3-year average harvest centered on

1980 and 1994.

Figure 16. Trends in tundra swan populations from 1969 to

1995 for eastern and western populations (USDI Fish and

Wildlife Service and Canadian Wildlife Service 1996).

Figure 18. Harvest trends from 1962 to 1995 for eastern and

western populations of tundra swans (D. Sharp, pers.

comm., USDI Fish and Wildlife Service, Office of Migratory

Bird Management, 1998).

1965 1970 1975 1980 1985 1990 1995

Year

0

20

40

60

80

100

120

Population (thousands)

Eastern

Western

1965 1970 1975 1980 1985 1990 1995

Year

0

1

2

3

4

5

6

7

Harvest (thousands)

Total

Eastern

Western
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999 35

Wildlife Resource Trends in the United States Flather, Brady, and Knowles

Figure 17. Trends in goose harvest from 1965 to 1995 by flyway (P. Padding, pers. comm., USDI Fish and Wildlife Service,

Office of Migratory Bird Management, 1996).

7 J.R. Sauer, pers. comm., U.S. Geological Survey, Biological

Resources Division, Patuxent Wildlife Research Center, 1997.

Breeding Bird Survey trend analysis. Data on file at the Rocky

Mountain Research Station.

Dove and woodcock populations

Both mourning dove and American woodcock abundance is monitored through call-count surveys that provide an annual index of population size (Dolton and

Smith 1997; Bruggink 1997). National trends in population indices for both species show evidence of declines,

although the magnitude of the decline appears to be much

less for mourning dove (figure 19) than woodcock (figure

20). This pattern is confirmed by the Breeding Bird Survey

data which indicates that doves are declining annually at

a rate of 0.3% compared to a 3.2% decline for woodcock

over the 1966 to 1996 period.7

Mourning dove call count data has shown evidence of

declining populations during the last 10 years in the

Eastern and Central management units, with long-term

(over the last 30 years) declines being detected in the

Central and Western units (figure 19). Declines in the

West have been estimated at 2.4% annually since 1966

(Dolton and Smith 1997). Although doves are adaptable

to human dominated lands (Dolton 1995), intensification

of some agricultural practices may be negatively impacting the breeding populations throughout much of the

bird’s range. Although agricultural land in the Eastern

management unit is positively related to dove populations (because much of the East is forested and agriculture

creates the edge habitats and food sources selected by

doves), increased uses of herbicides and insecticides (see

figure 6) along with shifts in the specific types of crops

planted may be related to observed dove declines in the

East (Martin and Sauer 1993). In the Central management

unit, the number of farms (a factor positively associated

Pacific

Central Mississippi Atlantic

National

'65 '70 '75 '80 '85 '90 '95

Year

0

200

400

600

800

1000

1200 Thousands

'65 '70 '75 '80 '85 '90 '95

Year

0

200

400

600

800

1000

1200 Thousands '65 '70 '75 '80 '85 '90 '95

Year

0

200

400

600

800

1000

1200 Thousands

'65 '70 '75 '80 '85 '90 '95

Year

0

200

400

600

800

1000

1200 Thousands

'65 '70 '75 '80 '85 '90 '95

Year

0

500

1000

1500

2000

2500 Thousands
36 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999

Flather, Brady, and Knowles Wildlife Resource Trends in the United States

Figure 19. Mourning dove population trends from 1966 to 1996 by management unit (Dolton and Smith

1997; Dolton, pers. comm., U.S. Fish and Wildlife Service, 1997).

Figure 20. Woodcock population trends from 1968 to 1996 by management unit (Bruggink 1996).

National:

Eastern

Region

Central

Region

65 70 75 80 85 90 95

1

1.5

2

2.5

3

3.5

4 Population index

65 70 75 80 85 90 95

1

1.5

2

2.5

3

3.5

4

65 70 75 80 85 90 95

1

1.5

2

2.5

3

3.5

4 Population index

Population index
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999 37

Wildlife Resource Trends in the United States Flather, Brady, and Knowles

with dove abundance) and the size of farms (a factor

negatively associated with dove abundance) were the

two environmental attributes that were consistently associated with dove population indices over time (Tomlinson

and Dunks 1993). The trend toward fewer and larger

farms has almost certainly had a negative impact on dove

populations in this region. The reasons for declining dove

populations in the West are more diverse. Certainly the

trend toward fewer and larger farms has also negatively

impacted dove numbers in the Western management

unit, but the clearing of shrublands and live oak trees, the

conversion of small-grain farming to cotton in some

areas, the conversion of fallow fields and pastureland to

cropland, and the increased use of pesticides and herbicides have all likely contributed to population declines in

the West (Reeves and others 1993).

Call-count trends for woodcock show remarkable consistency in the temporal pattern of decline in both the

Eastern and Central management units (figure 20). Longterm trends since 1968 indicate that the number of calling

woodcock heard have declined by 2.5% and 1.6% per year

in the Eastern and Central regions, respectively (Bruggink

1996). Within the last 10 years, declines in the Eastern

(-3.2%/year) and Central (-3.7%/year) units indicate that

the rate of decline may be accelerating. Woodcock select

early successional stages of second-growth hardwood

forests associated with fields and forest openings on

mesic sites. As with the mourning dove, the widespread

declines in woodcock breeding populations are thought

to be related to a deterioration of breeding habitats due to

forest succession and land use intensification (Straw and

others 1994).

Dove and woodcock harvests

More mourning doves are harvested than any other

game bird. About 50 million birds were harvested annually nationwide in the early 1970s and early 1980s with the

greatest number of harvested birds coming from the

Eastern management unit (figure 21). In the absence of

national surveys that monitor dove harvest, the trend

data reported here represent compilations from state

Figure 21. Mourning dove harvest trends from 1972 to 1989 by management unit (Sadler 1993).

National:

Western

Central

Eastern

1970 1975 1980 1985 1990

0

10

20

30

Millions

1970 1975 1980 1985 1990

0

10

20

30

Millions

1970 1975 1980 1985 1990

0

10

20

30

Millions

1970 1975 1980 1985 1990

0

10

20

30

40

50

60 Millions
38 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999

Flather, Brady, and Knowles Wildlife Resource Trends in the United States

wildlife agencies and should be interpreted carefully

(Sadler 1993). Given recent dove population trends, it is

not surprising that estimates for the 1988 and 1989 seasons show declining numbers of harvested birds. The

total harvest has declined by about 6% in the Eastern

management unit, and by more than 30% in the Central

and Western management units from the mid-1980s to the

late 1980s.

Unlike doves, woodcock harvests are monitored annually through wing-collection surveys that are used to

estimate the seasonal bag indices. Estimates are adjusted

to a 1969 base-year to facilitate temporal comparisons

(Bruggink 1997). Data since 1965 indicate that total seasonal bag indices have declined by 75% and 63% in the

Eastern and Central management units, respectively (figure 22). Record low seasonal bag indices were observed in

both management units in 1996. Although the results

from the wing-collection survey provide approximate

trends in harvest success, they should be evaluated judiciously because of the non-random sampling procedure

by which participants are selected (Straw and others 1994;

Bruggink 1997).

Furbearer Species

Collectively, furbearers constitute a resource that is

valued ecologically, recreationally, and commercially.

The management of furbearer resources in the United

States has recently undergone a period of rapid change

stemming from public sentiments that have spawned

new domestic and international legislation regulating fur

Figure 22. Woodcock harvest trends from 1965 to 1996 by management unit (Bruggink 1997).

Central Region

Eastern Region

'65 '70 '75 '80 '85 '90 '95

Year

0

2

4

12

14

'65 '70 '75 '80 '85 '90 '95

Year

2

4

6

8

10

12

14 Adjusted average seasonal bag

Adjusted average seasonal bag

10

8

6
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999 39

Wildlife Resource Trends in the United States Flather, Brady, and Knowles

trapping activities (Siemer and others 1994). Not only is

the management of furbearers controversial (Gentile 1987),

but the secretive nature of these species (Deems and

Pursley 1983) make it difficult to evaluate the population

status of most species. For many species the only available

information is on temporal trends in harvests, which is

likely more reflective of fur prices than population status.

The conflict associated with trapping and the limited

amount of information on resource status make furbearer

management uncertain and particularly contentious.

Furbearer populations

There have been very few comprehensive examinations of trends in furbearer populations nationwide. The

results from two national summaries (Sisson-Lopez 1979,

Deems and Pursley 1983) were discussed in the previous

RPA Assessment (see Flather and Hoekstra 1989). A more

recent compilation of furbearer population status was

completed for the Fur Resources Committee of the International Association of Fish and Wildlife Agencies.8

 A

telephone survey of state agency furbearer biologists was

used to assess the population status of those species that

were identified to be important based on factors such as

population status, harvest levels, damages, or management activities. The population status for the three most

important species, as determined by each state, was

evaluated based on the state biologists’ ranking of the

population relative to the carrying capacity of the habitat

within the state. Biologists also provided their professional judgment on the likely short-term (next 10 years)

population projection and the reasons contributing to

that future trend. Data were obtained from all states

except Hawaii.

We mapped the current population status for those

furbearer species that were reported by at least 10 states

including beaver, raccoon, muskrat, coyote, bobcat/lynx,

and red/gray fox. State populations of most furbearers

included in the survey were estimated to be at or above

carrying capacity (figure 23). Several species have the

potential to cause significant economic damage (e.g.,

beaver, coyote) or can be a public health concern (e.g.,

raccoon) when populations exceed a level that the habitat

can support. Few states reported furbearer populations

that were below carrying capacity, with beaver (four

states) and muskrat (three states) having the greatest

number of states reporting below-capacity populations.

Even though state agency biologists thought that many

furbearer populations exceeded the capacity of the habitat, many biologists project populations to continue to

increase (figure 23). For example, of the 28 states that

listed beaver as one of the most important furbearers,

about 70% are expecting population increases in the next

10 years. The pattern was similar for raccoons except that

proportionately more states are expecting raccoon populations to decline due to disease outbreaks. In addition to

improving habitat conditions, decreased harvest caused

by low fur prices were prominent reasons cited for population increases.

Fur harvest and price

Data on furbearer harvest trends are more complete

than data on population levels. Data on the number of

pelts taken by species and the average prices were provided by the Fur Resources Committee of the International Association of Fish and Wildlife Agencies9

 as derived from State Agency personnel.

The national trend in fur harvests has continued the

decline observed in the previous RPA Assessment (Flather

and Hoekstra 1989). Apart from a short-term deviation

during 1986-87 period when harvests increased by about

50%, harvests have declined from a peak of 20 million

pelts in 1980 to a low of 3 million pelts in 1991 (figure 24).

Since 1991 there have been modest increases in fur harvest, reaching 6 million pelts in 1995. Harvest trends for

the two most commonly harvested species, muskrat and

raccoon, are consistent with the national trend for all

species (figure 24).

There are no notable deviations from the national trend

within RPA regions (figure 24). Aside from the fact that

the North accounts for more than 60% of the total number

of pelts harvested nationwide, all regions showed peak

harvests during the late 1970s that were followed by

declines through the early 1990s.

Prices that trappers have received for their pelts is a

strong determinant of harvest. The price is in turn driven

by consumer demand for fur products, which is affected

by economic expansion, discretionary income levels, consumer preferences, and cyclical weather patterns.10 Prices

are obviously correlated with the harvest pattern

(figure 25). Peak prices in the late 1970s and the mid-1980s

correspond to peak harvest periods. Unlike harvest, average pelt prices do show regional variability that is associated with differences in species composition. Both the

Pacific Coast and Rocky Mountain Region have had

higher average pelt prices than the North or the South

since 1970. However, the total value of fur harvests (pelt

price x number of pelts) remains higher in eastern regions

8 Unpublished report, Southwick Associates. 1993. 1993 state

and provincial survey of furbearers with emphasis on nuisance

animals. Report on file at the Rocky Mountain Research Station.

9 R.G. Frederick, pers. comm., Department of Experimental

Statistics, Louisiana State University, 1997. Data on file at the

Rocky Mountain Research Station.

10 Unpublished report, Southwick Associates. 1993. An economic profile of the U.S. fur industry. Report on file at the Rocky

Mountain Research Station.
40 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999

Flather, Brady, and Knowles Wildlife Resource Trends in the United States

Figure 23. Furbearer population status in relation to carrying capacity and projected (10 year) population trends for selected

species (Unpublished report, Southwick Associates 1993. Report on file at the Rocky Mountain Research Station).

Pacific

Coast Rocky

Mountain

North

South

Pacific

Coast Rocky

Mountain

North

South

Pacific

Coast Rocky

Mountain

North

South

Pacific

Coast Rocky

Mountain

North

South

Pacific

Coast Rocky

Mountain

North

South

Pacific

Coast Rocky

Mountain

North

South

Beaver

Raccoon

Muskrat

Carrying capacity

Below At Exceeds

Population status Population projections

Decreasing Stable Increasing
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999 41

Wildlife Resource Trends in the United States Flather, Brady, and Knowles

Figure 23. (Cont’d.)

Pacific

Coast Rocky

Mountain

North

South

Pacific

Coast Rocky

Mountain

North

South

Pacific

Coast Rocky

Mountain

North

South

Pacific

Coast Rocky

Mountain

North

South

Pacific

Coast Rocky

Mountain

North

South

Pacific

Coast Rocky

Mountain

North

South

Red and Gray Fox

Coyote

Bobcat and Lynx

Population status Population projections

Carrying capacity

Below At Exceeds Decreasing Stable Increasing
42 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999

Flather, Brady, and Knowles Wildlife Resource Trends in the United States

because of the large number of pelts sold. After showing a

variable price pattern through the late 1980s in all regions,

average pelt prices have remained relatively stable since

1990 at levels that are about 60% lower than those

observed during the late 1970s and early 1980s (figure 25).

Although furs harvested by trapping remain an important source of pelts, most pelts used in fur garment

manufacturing are produced by fur farms that raise

primarily mink and fox.11 Recent trends in fur farm characteristics track well with those trends observed for

trapped furs (table 13). In 1987, 1,027 farms raised 4.12

million mink pelts worth about $177 million ($43.00/

pelt). For comparison, 362,000 mink were trapped in 1987

for a total value of $7.6 million ($23.26/pelt). By 1990, 771

farms (down 25% from 1987) raised 3.37 million pelts

with a total value of $85.8 million ($25.50/pelt). During

the same year, trappers harvested 142,000 mink with a

total value of $3.1 million ($25.38/pelt). From 1987 to

1990, trapped mink dropped from about 8% of the total

mink harvest (trapped + farmed) to about 4% of the total

mink harvest.

Increasingly, the global economy is affecting the North

American fur industry. The fur industry must continually

demonstrate compliance with the humane trapping standards adopted by the European Economic Community

(1991) if European markets are to remain open to North

American fur products. Similarly, fur imports from countries with lower labor costs are continually challenging

North American manufacturers to control costs to remain

competitive.12

Figure 24. Trends in total fur harvest (bar graph), and the harvest of muskrat and raccoon (line graph), by RPA Assessment

region from 1971 to 1995 (R.G. Frederick, pers. comm., Department of Experimental Statistics, Louisiana State University,

1997).

11 Unpublished report, Southwick Associates. 1993. An economic profile of the U.S. fur industry. Report on file at the Rocky

Mountain Research Station.

12 Unpublished report, Southwick Associates. 1993. An economic profile of the U.S. fur industry. Report on file at the Rocky

Mountain Research Station.

Pacific Coast

Rocky Mountain

North

South

National

1970 1975 1980 1985 1990 1995

Year

0

2

4

6

8

10 Millions

Muskrat

Raccoon

1970 1975 1980 1985 1990 1995

0

2

4

6

8

Millions

Muskrat

Raccoon

1970 1975 1980 1985 1990 1995

Year

0

400

800

1200

1600

Thousands

Raccoon Muskrat

1970 1975 1980 1985 1990 1995

Year

0

400

800

1200

1600

Thousands

Raccoon

Muskrat

1970 1975 1980 1985 1990 1995

Year

0

400

800

1200

1600

Thousands

Raccoon Muskrat

1970 1975 1980 1985 1990 1995

Year

0

5

10

15

20

25 Millions

1970 1975 1980 1985 1990 1995

Year

0

2

4

6

8

10

12 Millions

1970 1975 1980 1985 1990 1995

Year

0

1

2

3

4

5

6

Millions

1970 1975 1980 1985 1990 1995

Year

0

2

4

6

8

10

12 Millions

1970 1975 1980 1985 1990 1995

Year

0

2

4

6

8

10

12 Millions

Year
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999 43

Wildlife Resource Trends in the United States Flather, Brady, and Knowles

Nongame Species

For our purposes, nongame species are defined as

those terrestrial vertebrate species that are not consumptively taken for sport, subsistence, or profit. As such,

nongame species comprise the majority of the approximately 3,000 vertebrates that are resident or seasonal

inhabitants within the United States (Flather and Hoekstra

1989). Unfortunately, there are very few data sources

available for most nongame species that would permit an

exploration of national and regional population trends.

One taxonomic group where sufficient population information does exist to support broad-scale analyses of

abundance trends is birds.

Breeding bird populations

The North American Breeding Bird Survey (BBS) was

established in 1966 to provide data on breeding bird

populations along road-side routes across the continental

Figure 25. Trend in average pelt price (across all species) and total fur value by RPA Assessment region from 1971 to 1995.

Both price and value have been adjusted for inflation (1995 constant dollars) (R.G. Frederick, pers. comm., Department of

Experimental Statistics, Louisiana State University, 1997). a

Average price and total value have been adjusted for inflation based

on producer price indices for “hides, skins, leather, and related products” (Council of Economic Advisors 1997).

Table 13—Trends in mink and fox fur farms. (Unpulbished

report, Southwick Associates [1993]. Report on file at the

Rocky Mountain Research Station.)

Species/farm ------------------- Year -------------------

characteristics 1987 1990

Mink

number of farms 1,027 771

number of pelts 4.12 million 3.37 million

value of pelts $177.2 million $85.8 million

pelt price $43.00 $25.50

Fox

number of farms 112 84

number of pelts -a -

value of pelts $19.3 million $9.3 million

pelt price - -

aNo data.

Pacific Coast

Rocky Mountain

North

South

National

'70 '95

Year

0

20

40

60

80

100

120

'70 '75 '80 '85 '90 '95

Year

0

20

40

60

80

100

120

'70 '75 '80 '85 '90 '95

Year

0

20

40

60

80

100

Average price (1995 dollars)

'70 '75 '80 '95

Year

0

20

40

60

80

100

120

'85 '90 '95

Year

0

100

150

200

250

300

'70 '75 '80 '85 '90 '95

Year

0

50

100

150

200

250

300

'70 '75 '80 '85 '90 '95

Year

0

50

100

150

200

250

300 Total value (million 1995 dollars)

'70 '75 '80 '85 '90 '95

Year

0

100

150

200

300

'70 '75 '80 '85 '90 '95

Year

0

100

200

300

400

500 Total value (million 1995 dollars) a

'70 '75 '80 '85 '90 '95

Year

0

20

40

60

80

100

120 Average price (1995 dollars) a

Total value (million 1995 dollars)

'75 '80 '85 '90

Average price (1995 dollars)

120

Average price (1995 dollars)

Total value (million 1995 dollars)

Total value (million 1995 dollars)

250

50

'85 '90

Average price (1995 dollars)

'70 '75 '80

50
44 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999

Flather, Brady, and Knowles Wildlife Resource Trends in the United States

United States and southern Canada. Routes occur along

secondary roads, are 24.5 miles long, and are surveyed

once a year in June. During each survey, all birds seen or

heard along the route are counted at 50 stops placed at 0.5-

mile intervals. More than 3,400 routes allowed us to

examine the relative abundance trends for approximately

400 species nationwide for the period 1966 to 1996.13 For

details concerning the design and implementation of the

BBS, see Droege (1990).

Relative abundance trends for each species was summarized two ways. First, we estimated the number of

species with statistically significant increasing, decreasing, or stable trends nationwide and for each region.

Secondly, we grouped birds according to life-history

characteristics including: nest type/location (cavity, open

cup, ground or low, midstory or canopy nesters), migration status (neotropical migrant, short-distance migrant,

permanent resident), and breeding habitat (woodland,

shrubland, grassland, wetland or open water, urban nesting) according to the classification of Peterjohn and Sauer

(1993). The number of species with increasing, decreasing, or stable trends was estimated separately for each

life-history group. To qualify for analysis, each bird species had to have been detected on at least 15 routes. We

counted species as having an increasing or decreasing

trend if the slope of the regression differed from zero with

probability P ≤ 0.10. Regression slopes that were not

significantly different from 0 (P > 0.10) were counted as

stable populations.

Nationally, the majority of surveyed species (n=194

species, 48% of all species analyzed) have had stable

trends in relative abundance. The number of species with

increasing (n=109) and decreasing (n=103) trends were

nearly equal (figure 26, table 14). Regionally, the North

had the greatest proportion of increasing species (31%)

and the South had the greatest proportion of decreasing

species (35%). Both the Rocky Mountain and Pacific Coast

regions were characterized by a high proportion of species with stable trends (64 and 61%, respectively).

Among the 12 bird life-history groups we examined

(figure 26 and table 14), those with the greatest proportion

of declining bird species were observed among species

that nest in or around urban areas or human settlement

(54%), nest in grassland habitats (44%), or nest on or near

the ground (36%). Those life-history groups with the

greatest proportion of species with increasing trends

included wetland or open water nesting species (40%),

cavity nesting species (37%), or short-distance migrant

species (31%). We did not observe strong evidence for

consistent declines among those species that winter in the

neotropics. Nearly 55% of neotropical migrant species

have had stable populations during the 1966-1996 period.

However, of the species with significant trends, 27% of

neotropical migrants had declining trends compared to

19% with increasing trends.

Given the habitat trends reviewed earlier, the abundance trends for urban- and wetland-associated species

were surprising. Both of these species groups show trends

that deviate from those expected given the trends in

habitat. Nearly 54% of those species associated with

urban and intensively farmed habitats showed significantly declining trends over the 1966-1996 period, despite

the fact that urban habitats have increased substantially

over this period (see figure 2, table 1). Similarly, a high

proportion of wetland-associated species have shown

abundance increases (40%) despite declines in wetland

habitats (see figure 7). Although the pattern observed for

urban species may be associated with “clean farming”

practices that have increased nest disturbance and reduced the amount of waste grains and other foods that

support these species (Sauer and others 1997), it may also

be a function of biases associated with the location of

routes and BBS observers. Because urban associated species are not of interest to most birders, it has been speculated that BBS observers may detect fewer individuals of

this species group over time because they “tune out” these

species in favor of other species (Sauer and others 1997).

There is also a chance that populations of urban species

show a decline because routes have had to be relocated

because urban encroachment and increased traffic noise

makes it difficult to detect species. Similar cautions apply

to wetland associated species (Sauer and others 1997).

However, there have been several agricultural programs

(e.g. CRP, Wetlands Reserve Program) that have improved nesting conditions associated with wetland habitats (Robinson 1997). In both cases it will be difficult to

resolve these apparent contradictions between abundance

and habitat trends in the absence of information on habitat along BBS routes.

The trends in grassland nesting birds also warrant

examination with respect to the habitat trends reviewed

earlier. Over the 1966 to 1996 period, grassland nesting

birds showed the lowest proportion of species with increasing trends (11%) and the second highest proportion

of species with declining trends (44%)—a pattern consistent with Knopf’s (1995) findings. Given the retirement of

nearly 36 million acres of cropland that was planted to

perennial cover in the late 1980s as part of the CRP, one

would expect grassland bird populations to have increased in response to this program. Evidence of a positive population response by grassland birds to the CRP

has been observed at local (Johnson and Swartz 1993) and

regional (Reynolds and others 1994) scales, but on initial

inspection appears to be inconsistent among species at the

national scale using the BBS. However, by viewing the

13 J.R. Sauer, pers. comm., U.S. Geological Survey, Biological

Resources Division, Patuxent Wildlife Research Center, 1997.

Breeding Bird Survey trend analysis. Data on file at the Rocky

Mountain Research Station.
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999 45

Wildlife Resource Trends in the United States Flather, Brady, and Knowles Figure 26. The proportion of bird species with increasing, decreasing, and stable trends from 1966 to 1996 by RPA Assessment region. Bird species have been grouped by broad life history characteristics including nest type/location (cavity, open cup, ground or low, midstory or canopy nesters), migration status (Neotro- pical migrant, short-distance migrant, permanent resident), and breeding habitat (woodland, shrubland, grassland, wetland or open water, urban nesting). Species were counted as increasing or decreasing if the trend was significantly different from 0 at P≤0.1 (J.R. Sauer, U.S. Geological Survey, Biological Re- sources Division, Patuxent Wildlife Research Center, 1997). Pacific Coast Rocky Mountain North South National: All Birds Cavity Open Cup Ground Midstory Neotropical Short Distance Perm. Resident Woodland Shrubland Grassland Wetland Urban0% 20% 40% 60% 80% 100% Increasing Decreasing Stable All Birds Cavity Open Cup Ground Midstory Neotropical Short Distance Perm. Resident Woodland Shrubland Grassland Wetland Urban0% 100% All Birds Cavity Open Cup Ground Midstory Neotropical Short Distance Perm. Resident Woodland Shrubland Grassland Wetland Urban0% 20% 40% 60% 80% 100%All Birds Cavity Open Cup Ground Midstory Neotropical Short Distance Perm. Resident Woodland Shrubland Grassland Wetland Urban0% 20% 40% 60% 80% 100%All Birds Cavity Open Cup Ground Midstory Neotropical Short Distance Perm. Resident Woodland Shrubland Grassland Wetland Urban0% 20% 40% 60% 80% 100% 20% 40% 60% 80%
46 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999

Flather, Brady, and Knowles Wildlife Resource Trends in the United States

Table 14--Number of breeding bird species with increasing, decreasing, and stable trends from 1966 to 1996 by life-history characteristic 

for the total U.S. and RPA Assessment region (J.R. Sauer, pers. comm., U.S. Geological Survey, Biological Resources Division, Patuxent 

Wildlife Research Center, 1997). 

Total U.S. North 

Total 

Species 

Increasing 

species 

(%) 

Decreasing 

species 

(%) 

Stable 

species 

(%) 

Total 

species 

Increasing 

species 

(%) 

Decreasing 

species 

(%) 

Stable 

species 

(%) 

All species 406 109 (26.8) 103 (25.4) 194 (47.8) 209 64 (30.6) 59 (28.2) 86 (41.1) 

Nest type/location 

 Cavity 60 22 (36.7) 14 (23.3) 24 (40.0) 27 14 (51.9) 4 (14.8) 9 (33.3) 

 Open cup 180 35 (19.4) 55 (30.6) 90 (50.0) 105 22 (21.0) 37 (35.2) 46 (43.8) 

 Ground/low 115 19 (16.5) 42 (36.5) 54 (47.0) 62 14 (22.6) 25 (40.3) 23 (37.1) 

 Midstory/canopy 118 36 (30.5) 28 (23.7) 54 (45.8) 72 23 (31.9) 16 (22.2) 33 (45.8) 

Migration status 

 Neotropical 134 25 (18.7) 36 (26.9) 73 (54.5) 85 18 (21.2) 21 (24.7) 46 (54.1) 

 Short distance 104 32 (30.8) 34 (32.7) 38 (36.5) 61 23 (37.7) 23 (37.7) 15 (24.6) 

 Permanent resident 89 21 (23.6) 22 (24.7) 46 (51.7) 25 10 (40.0) 4 (16.0) 11 (44.0) 

Breeding habitat 

 Woodland 131 35 (26.7) 29 (22.1) 67 (51.1) 76 23 (30.3) 13 (17.1) 40 (52.6) 

 Shrubland 85 14 (16.5) 26 (30.6) 45 (52.9) 34 9 (26.5) 10 (29.4) 15 (44.1) 

 Grassland 27 3 (11.1) 12 (44.4) 12 (44.4) 14 1 (7.1) 10 (71.4) 3 (21.4) 

 Wetland/open water 90 36 (40.0) 13 (14.4) 41 (45.6) 45 16 (35.6) 14 (31.1) 15 (33.3) 

 Urban 13 2 (15.4) 7 (53.8) 4 (30.8) 12 3 (25.0) 7 (58.3) 2 (16.7) 

BBS over the last 30 years, more recent trends may be

masked by the variation over this long time period. When

we estimated the trends in grassland nesting birds from

1985 to 1996, a period of time when the CRP was implemented, we do see some evidence for a positive effect at

a national scale. Over this period, the proportion of

grassland nesting birds with upward population trends

increased to 19%, while the proportion of species with

declining trends decreased to 22%.

Abundance trends among species groups vary considerably by RPA region. A greater proportion of bird abundance trends in the South declined when compared to

other regions. The average proportion14 of species with

declining trends across all groups was 44% in the South.

Greater than 40% of the species showed declining trends

for grassland nesting birds (70%), ground nesting birds

(57%), shrubland nesting birds (53%), open-cup nesters

(49%), urban nesting birds (46%), and neotropical migrants (41%). The only groups in the South that had more

species with increasing than decreasing trends were cavity and wetland nesting species.

The North had the next highest average proportion of

species with declining trends (34%). As in the South,

species groups with a relatively high proportion of species with declining trends included grassland nesting

birds (71%), urban nesting birds (58%), and ground nesting birds (40%). Half of the bird groups in the North

showed a greater proportion of increasing species and

include cavity nesters, midstory and canopy nesters,

permanent residents, woodland associated species, and

wetland associated species.

The average proportion of species with declining trends

were much lower in the Pacific Coast (26%) and Rocky

Mountains (13%) than in the eastern regions. The only

species groups in the Rocky Mountain region that showed

more decreasing than increasing species were grassland

and ground nesting species. Again, the trend in grassland

nesting birds warrant remark. Because many of the acres

enrolled in CRP are concentrated in the Rocky Mountain

region (USDA Natural Resources Conservation Service

1997), we may expect short-term trends in grassland birds

to deviate from the 30-year trend. From 1966 to 1996, 12%

of the grassland nesting species had increasing trends and

16% had declining trends in the Rocky Mountain region.

From 1985 to 1996, the number of grassland nesting

14 Estimated as a weighted average where the number of

species in each species group served as the weight.
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999 47

Wildlife Resource Trends in the United States Flather, Brady, and Knowles

Table 14 (Cont'd.) 

South Rocky Mountain Pacific Coast 

Total 

species 

Increasin

g 

species 

(%) 

Decreasing 

species 

(%) 

Stable 

species 

(%) 

Total 

species 

Increasin

g 

species 

(%) 

Decreasing 

species 

(%) 

Stable 

species 

(%) 

Total 

species 

Increasin

g 

species 

(%) 

Decreasing 

species 

(%) 

Stable 

species 

(%) 

 210 47 (22.4) 74 (35.2) 89 (42.4) 270 67 (24.8) 31 (11.5) 172 (63.7) 220 40 (18.2) 46 (20.9) 134 (60.9) 

 29 10 (34.5) 8 (27.6) 11 (37.9) 38 9 (23.7) 2 (5.3) 27 (71.1) 34 6 (17.6) 7 (20.6) 21 (61.8) 

 86 18 (20.9) 42 (48.8) 26 (30.2) 122 25 (20.5) 17 (13.9) 80 (65.6) 88 14 (15.9) 25 (28.4) 49 (55.7) 

 54 7 (13.0) 31 (57.4) 16 (29.6) 81 12 (14.8) 13 (16.0) 56 (69.1) 53 8 (15.1) 11 (20.8) 34 (64.2) 

 65 20 (30.8) 20 (30.8) 25 (38.5) 86 25 (29.1) 10 (11.6) 51 (59.3) 70 10 (14.3) 21 (30.0) 39 (55.7) 

 76 12 (15.8) 31 (40.8) 33 (43.4) 87 19 (21.8) 14 (16.1) 54 (62.1) 64 11 (17.2) 13 (20.3) 40 (62.5) 

 50 17 (34.0) 20 (40.0) 13 (26.0) 85 20 (23.5) 8 (9.4) 57 (67.1) 67 10 (14.9) 22 (32.8) 35 (52.2) 

 42 9 (21.4) 16 (38.1) 17 (40.5) 55 12 (21.8) 6 (10.9) 37 (67.3) 51 7 (13.7) 8 (15.7) 36 (70.6) 

 58 15 (25.9) 19 (32.8) 24 (41.4) 74 18 (24.3) 8 (10.8) 48 (64.9) 64 10 (15.6) 16 (25.0) 38 (59.4) 

 43 8 (18.6) 23 (53.5) 12 (27.9) 62 14 (22.6) 6 (9.7) 42 (67.7) 48 6 (12.5) 11 (22.9) 31 (64.6) 

 10 7 (70.0) 3 (30.0) 25 3 (12.0) 4 (16.0) 18 (72.0) 11 2 (18.2) 2 (18.2) 7 (63.6) 

 46 11 (23.9) 8 (17.4) 27 (58.7) 48 18 (37.5) 4 (8.3) 26 (54.2) 46 14 (30.4) 3 (6.5) 29 (63.0) 

 13 2 (15.4) 6 (46.2) 5 (38.5) 12 3 (25.0) 2 (16.7) 7 (58.3) 9 1 (11.1) 4 (44.4) 4 (44.4) 

species with increasing trends grew to 28% while the

number with declining trends decreased slightly to 12%

providing very tentative evidence for a regional affect of

CRP. Because other factors could have also changed

during this time period (e.g., weather), it is not possible,

in the absence of further research, to attribute grassland

bird population increases to the CRP.

Bird diversity and land use

Diversity (i.e., the patterns of species distributions and

abundances) has long been a central issue of ecological

study (May 1986) and is receiving a renewed and urgent

interest (Rosenzweig 1995) by conservation planners in

response to global degradation of biological diversity.

Much of the focus on conserving biological diversity has

been in the species-rich tropics (Raven 1988; Allan and

Flecker 1993). Although the tropics clearly warrant conservation attention, it is important to acknowledge the

extent to which natural environments have been altered

by human activity in temperate regions (Carlson 1988:22;

Ricketts and others 1999). Franklin (1988:166) observed

that “[m]any ecosystems and organisms in temperate

zones have been entirely eliminated, and most remaining

examples of natural ecosystems are fragmented and highly

modified.” Concern exists that as land management intensifies to support growing human populations, natural

variety will be reduced, leading to diminished productivity or limited capacity to recover from natural or humancaused disturbance. Ecosystem simplification under resource extraction and land use intensification is, in fact,

the essence of the biological diversity issue (Roberts 1988;

Raven 1990; Koshland 1991; Ehrlich and Wilson 1991;

Nelson and Serafin 1992), but empirical investigation of

this pattern across broad geographic regions has been

limited. Identifying and monitoring elements of biological diversity is a complex undertaking at any scale of

analysis and particularly difficult over large geographic

areas (Lubchenco and others 1991).

Complexity notwithstanding, a basic ecological inventory is fundamental to describing and understanding

regional patterns of diversity. Unfortunately, much of the

information that could support macroecological investigation of biodiversity patterns is restricted to a subset of

well-studied taxa. One well-studied taxon that does lend

itself to investigation of regional diversity patterns is

birds. Despite this taxonomic limitation, birds have been

found to be useful indicators of broad-scale habitat changes
48 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999

Flather, Brady, and Knowles Wildlife Resource Trends in the United States

Figure 27. Pattern of bird species richness based on species counts observed on BBS routes.

11 to 34

35 to 41

42 to 48

49 to 54

55 to 72

# Species

(Koskimies 1989). What follows is a review of several case

studies that address the impacts of land use activities on

several attributes of breeding bird diversity. These case

studies focus primarily on patterns of association among

birds and land use in the eastern United States.

The simplest description of bird diversity patterns

across the United States is species richness. Based on BBS

data, bird species richness is high in the Northeast, along

the southern Appalachians, in areas of the Pacific Northwest, and along the tidewater area of northeastern North

Carolina and the Chesapeake Bay (figure 27). Areas of

relatively low bird species richness are located along the

shortgrass prairie of the western Great Plains and in the

desertic basin and range region of the Southwest. Because

some species are always missed during bird count surveys, it is important to note that the bird richness estimates depicted in figure 27 are minimum estimates of

species richness. Although these bird richness estimates

are biased low, they do depict the relative richness among

regions accurately (Sauer and others 1997).

There are many causes for the regional variation in bird

richness depicted in figure 27. Fundamentally, differences in the amount of energy received at any given

location have been shown to explain much of the regional

variation in species richness for many taxa, including

birds (Currie 1991, Brown 1995). In order to explore the

potential impacts of land use practices on observed bird

richness, there is a need to first control for the inherent

variation in species richness that is unrelated to land use

activities. This was accomplished by first estimating the

expected species pool under natural conditions from

range map data, and comparing the expected species

composition to that observed on BBS routes within various physiographic strata. This approach resulted in an

estimated ratio of bird species counts from the BBS to the

expected species count—a ratio that has been interpreted

as an index of bird community integrity (for details see

Flather and others 1992).

Flather and others (1992) used an index of vertical

habitat complexity as their measure of land use intensification. The habitat structure index was calculated as the

ratio of observed habitat layers (vertical vegetation strata

including tree canopy, tree bole, shrub layer, soil surface

vegetative layer, and subsurface) at site to the expected

number of habitat layers under the potential natural

vegetation defined by Küchler (1964). Bird community
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999 49

Wildlife Resource Trends in the United States Flather, Brady, and Knowles

integrity was found to be positively associated with the

habitat structure index (figure 28) within 35 physiographic

strata located in the forested region of the eastern United

States. However, only 34% of the total variation in bird

community integrity was accounted for by the vertical

habitat structure index. More complex multiple linear

regression models that incorporated landscape composition (i.e., number of land types, land type dominance, and

the proportion of urban land) and the spatial structure of

forest patches resulted in a model that accounted for 63%

of the variation in bird species integrity. These results

support the hypothesis that as land uses intensify regionally, a smaller proportion of the expected bird community

is observed in any given year, at least for forested ecosystems across the eastern United States.

Changes in bird diversity can result from changes in

species richness (as we reviewed above), or it can result

from changes in the relative commonness and rarity of

species comprising the assemblage. Changes in the commonness and rarity among species found in a given

geographic area is often termed the evenness component

of species diversity (Magurran 1988). It has been hypothesized that conversion of natural habitats to humandominated land uses is associated with increased dominance of opportunistic species (sometimes these are exotic species) that can exploit disturbed habitats and increased rarity of those native species considered to be

habitat specialists. This hypothesis is derived from the

stress ecology literature (Barrett and others 1976; Odum

1985; Rapport and others 1985) and was tested by Flather

(1996) using breeding birds in forested ecosystems in the

eastern United States.

The evenness component of bird diversity was based

on species-accumulation curves (see Flather 1996 for

details). As one samples bird species from a particular

assemblage, new species are initially encountered rapidly. As samples accumulate, the rate of encounter declines and the total number of species in the collection is

approached asymptotically. Species-accumulation curves

were derived using statistical simulation within physiographic strata across forested regions of the East using

the BBS. All accumulation curves were fit empirically

with a single functional form, which would permit comparisons of parameters that describe each curve among

physiographic strata. The parameter related to the rate of

species accumulation was estimated for each physiographic stratum.

For each physiographic stratum, Flather (1996) also

estimated the proportion of cropland and urban land

within each stratum as an index of land use intensity.

Physiographic strata with a greater proportion of agricultural and urban land uses accumulated species more

slowly than landscapes that retained a greater proportion

of natural habitats (figure 29). Those strata with the

lowest rates of species accumulation (lower right in figure

29) are found primarily in the eastern portion of the

Figure 28. The relation between bird community integrity and

vertical habitat structure for 35 physiographic strata located

in forested ecosystems of the eastern United States (Flather

and others 1992).

Figure 29. Rate of bird species accumulation as a function of

land use intensity (Flather 1996).

0.1 0.2 0.3 0.4 0.5 0.6

Vertical Habitat Structure (VHS)

0.2

0.4

0.6

0.8

1

Bird Community Integrity (BCI)

BCI = 0.56 + 0.35(VHS)

r = 0.34, F = 18.45, P < 0.0001 2

-0.4 -0.3 -0.2 -0.1 0 0.1 0.2 0.3 0.4 0.5

Land use intensity

0

0.1

0.2

0.3

0.4

-0.1

-0.2

-0.3

Rate of accumulation
50 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999

Flather, Brady, and Knowles Wildlife Resource Trends in the United States

Figure 30. Proportion of total individual birds observed along BBS routes that were exotics based on a 10-year mean from 1980

to 1990.

0.08 to 3.7

3.7 to 6.2

6.2 to 9.4

9.4 to 14.1

14.1 to 44.0

% Exotics

United States corn belt. These strata are important centers

for agriculture and they are also heavily urbanized. Strata

that had high rates of species accumulation were not

clustered geographically and included the Western Coastal

Plain, the Southern Piedmont, and the Highland Rim and

Pennyroyal area of central Tennessee and Kentucky. One

physiographic stratum that accumulated species at a rate

much greater than expected given the proportion of land

under crop and urban development was a region in

northwestern Kentucky and southern Indiana (the data

point in figure 29 with the greatest rate of species accumulation). One possible explanation for this pattern is that

this landscape includes a fairly high proportion of National Forest land that has retained some of the natural

vegetation characteristics of this region. Consequently,

the National Forest may be serving as a source habitat for

bird species that would otherwise be rare or absent from

this physiographic region given its current pattern of land

use on private lands.

The relation between land use intensity and speciesaccumulation rate was consistent with predictions of

ecosystem behavior under anthropogenic land use stress.

Rapport and others (1985) noted that physical restructuring associated with land use conversion from natural

habitats (e.g., forest and wetland) to human-dominated

land uses (e.g., agriculture and urban land) is associated

with a degradation of species diversity. The reduced rate

of species accumulation under land use intensification is

indicative of a disparate species-abundance distribution,

with the bird assemblage being comprised of a greater

proportion of rare and distributionally restricted species,

and a greater dominance (i.e., high abundance) of a few

opportunistic species that do well in simpler, disturbed

habitats (Urban and others 1987; Cotgreave and Harvey

1994). This latter pattern is illustrated well by the proportion of individuals observed on BBS routes that are exotic

species (figure 30). Areas of the country dominated by

agricultural or urban land use observe a relatively high

proportion of exotic birds. Recall that the corn belt region

was characterized by relatively low species accumulation

rates, which is explained in part by the numerical dominance of exotic species in these areas.

The case studies reviewed above show that geographic

variation in bird diversity attributes was associated with

variation in landscape structure attributes. A question

that still remains, is how bird diversity changes over time

and whether (and to what extent) those temporal changes

can be attributed to changes in landscape structure. A
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999 51

Wildlife Resource Trends in the United States Flather, Brady, and Knowles

prediction from the stress ecology literature is that land

use intensification can destablize populations resulting in

marked increases in the amplitude of population fluctuations (Rapport and others 1985). If this is true, then large

scale monitoring efforts like the BBS would be expected to

see greater incidence of local extinction events (i.e., variable bird species occurrence among survey routes).

To test this prediction, Boulinier and others (1998)

estimated the temporal variation in species richness for

those bird species that are thought to be sensitive to the

area of forest patches (as defined by Robbins and others

1989) along BBS routes in the mid-Atlantic region of the

eastern United States. Landscape metrics were estimated

from high-altitude aerial photography from a 19.7 km

scene (half the length of a BBS route) centered on each

route. The average size of forest patches within each scene

was used as an index of forest fragmentation. Comparison of temporal variation in species richness with forest

fragmentation supported the hypothesis that temporal

variability of forest bird richness over a 22-year period

was associated with landscape structure. In particular,

species richness of area-sensitive forest birds was more

variable in landscape scenes with small average forest

patches (i.e., high fragmentation) than in scenes with

large average forest patch sizes. These results confirm

that more fragmented landscapes not only reduce the

numbers of some forest breeding birds, but fragmentation also may be responsible for destabilizing bird community structure through increased rates of local extinction and turnover.

The results from these case studies all emphasize the

need to empirically examine the relationships between

biological diversity and landscape structure. Results also

support the notion that the composition, extent, and

spatial layout of land types have the potential to fundamentally affect the flow of ecosystem goods and services

in a region (Daily and others 1997). Land use intensification results in simplified bird communities with higher

temporal variation in composition, which may presage

broader-scale extinction events. However, because the

composition of species assemblages varies geographically (Huston 1994), relationships with land use activities

may also vary. For example, it is known that neotropical

migrant birds comprise the majority of species (>50%) in

the East yet comprise a much smaller proportion of the

bird species inhabiting the Great Plains (about 10%) or the

West (< 15%) (MacArthur 1959). In a study of landscape

structure influences on eastern breeding birds, Flather

and Sauer (1996) found that the abundance of neotropical

migrant birds as a group was more sensitive to landscape

structure than were permanent residents or temperate

migrants. Neotropical migrants tended to be more abundant in landscapes with a greater proportion of forest and

wetland habitats, fewer edge habitats, larger forest patches,

and forest habitats well dispersed throughout the landscape. Permanent residents showed few correlations with

landscape structure, and temperate migrants were associated with habitat diversity and edge attributes rather

than with the amount, size, and dispersion of forest

habitats. Given the variation in how species with different

life history strategies (e.g., migration status) were associated with the arrangement of land use and land cover, the

patterns observed in the eastern United States may not

hold for other geographic areas.

Research that has investigated the influence of land use

and land cover on bird species at macroecological scales

has focused primarily on spatial variation—that is, trying

to explain why bird abundance or bird communities vary

from one locale to the next. What is currently lacking is a

commensurate set of investigations that examine the

relationship between landscape structure and bird distribution and abundance over time. In order to more fully

examine the relationships between landscapes and biological diversity, there is a critical need for temporally

consistent land base inventories that permit the estimation of changes in landscape composition and configuration.

Amphibian populations

Within the borders of the continental United States

there are approximately 230 species of amphibians (140

salamanders and 90 frogs and toads) (Bury and others

1995). The activities of humans have long been thought to

affect amphibian populations, yet measures to conserve

amphibians have lagged relative to other taxa (Bury and

others 1980). One manifestation of this conservation neglect has been the absence of long-term data that monitors

the status of amphibian populations (Pechmann and others

1991).

Many reports have documented local and regional

amphibian declines in both disturbed and pristine habitats (see Blaustein and Wake 1990). However, evaluating

this apparent widespread decline is made difficult by the

dearth of geographically widespread and long-term survey data, which make the status of amphibian populations one of the more controversial issues in conservation

biology (Reed and Blaustein 1995). Although there is

general agreement that habitat destruction and other

human-related impacts have resulted in some local population reductions or extinction (Pechmann and Wilbur

1994), there is less agreement concerning how widespread the decline is. The specific factors that may be

contributing to the purported decline in amphibian numbers are disputed, as well. Part of the difficulty is that

some amphibian populations exhibit large natural population fluctuations that may make it difficult to detect

human-caused declines—a pattern that further highlights

the need for long-term monitoring (Pechmann and others

1991; Hecnar and M’Closkey 1996).
52 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999

Flather, Brady, and Knowles Wildlife Resource Trends in the United States

Acris crepitans *

Acris crepitans blanchardi *

Ambystoma californiense * *

Ambystoma cingulatum *

Ambystoma gracile * *

Ambystoma jeffersonianum *

Ambystoma laterale *

Ambystoma mabeei *

Ambystoma

 macrodactylum croceum *

Ambystoma macrodactylum

 sigillatum * *

Ambystoma maculatum *

Ambystoma platineum *

Ambystoma talpoideum *

Ambystoma tigrinum * * *

Ambystoma tigrinum stebbinsi *

Ambystoma tremblayi *

Aneides aeneus *

Aneides ferreus *

Ascaphus truei * *

Batrachoseps aridus * *

Batrachoseps attenuatus

Batrachoseps campi * *

Batrachoseps pacificus pacificus *

Batrachoseps simatus *

Batrachoseps sp. 1 *

Batrachoseps sp. 2 *

Batrachoseps sp. 3 *

Batrachoseps sp. 4 *

Batrachoseps sp. 5 *

Batrachoseps stebbinsi *

Bufo alvarius *

Bufo boreas * *

Bufo canorus *

Bufo exsul * *

Bufo hemiophrys baxteri *

Bufo houstonensis *

Bufo microscaphus *

Bufo microscaphus californicus * *

Bufo microscaphus

 microscaphus * *

Bufo nelsoni * *

Bufo wrighti *

Cryptobranchus alleganiensis *

Cryptobranchus bishopi *

Desmognathus auriculatus *

Desmognathus fuscus *

Desmognathus fuscus conanti *

Dicamptodon copei *

Dicamptodon ensatus * *

Ensatina eschscholtzii croceator * *

Ensatina eschscholtzii klauberi * *

Eurycea longicauda *

Eurycea lucifuga *

Gastrophryne carolinensis *

Gyrinophilus porphyriticus *

Hemidactylium scutatum * *

Hydromantes brunus * *

Hydromantes platycephalus * *

Hydromantes shastae * *

Hyla andersonii *

Hyla avivoca *

Hyla chrysoscelis *

Hyla crucifer *

Hyla gratiosa * *

Necturus maculosus *

Necturus spp. *

Notophthalmus viridescens *

Notophthalmus perstriatus *

Table 15—Amphibians whose population status is of conservation concern1 (from Vial and Saylor 1993).

 Pacific Rocky Pacific Rocky

 Species Coast Mountain North South Species Coast Mountain North South

Although continuous long-term records of amphibian

populations are lacking, comparisons between contemporary and historical surveys do offer a more temporally

extensive perspective. In a study of regional frog fauna in the

Yosemite National Park area, Drost and Fellers (1996) found

that five of seven frog and toad species had suffered

serious declines from 1915 to 1992. These declines have

occurred in sites that have been relatively undisturbed

over the period of comparison, but the cause of the

declines remains undetermined.

The lack of basic monitoring information notwithstanding, there have been attempts to compile status

evaluations from professional herpetologists over large

geographic areas. A report from the Declining Amphibian Populations Task Force summarized the findings of

this compilation as of December 1993 (Vial and Saylor
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999 53

Wildlife Resource Trends in the United States Flather, Brady, and Knowles

1993). Because this synthesis was based on combining

results from independent local studies, it lacked the rigor

that can be achieved with regional or national monitoring

protocols. Therefore, the patterns summarized here must

be viewed as tentative.

A total of 120 species and subspecies were determined

by Vial and Saylor (1993) to have downward population

trends in the continental United States. The greatest

number of species or subspecies with evidence of declining populations occurred in the Pacific Coast region,

followed by the North, Rocky Mountain, and the South

(table 15). The number of genera determined to have

species or subspecies with declining populations indicates that the North has the greatest number of genera

followed by the Pacific Coast and South, and the Rocky

Mountains. Given that the greatest diversity of amphibPhaeognathus hubrichti *

Plethodon caddoensis *

Plethodon dunni *

Plethodon elongatus * *

Plethodon fourchensis *

Plethodon hubrichti *

Plethodon kiamichi *

Plethodon larselli *

Plethodon nettingi *

Plethodon ouachitae *

Plethodon shenandoah *

Plethodon stormi * *

Plethodon vandykei *

Plethodon wehrlei *

Pseudacris (Hyla) regilla *

Pseudacris brachyphona *

Pseudacris feriarum *

Pseudacris streckeri *

Pseudacris streckeri illinoensis * *

Pseudacris streckeri sterckeri *

Pseudacris triseriata *

Pseudotriton montanus *

Pseudotriton ruber *

Rana a. aurora * *

Rana a. draytoni * *

Rana areolata *

Rana aurora *

Rana blairi * *

Rana boylii *

Rana capito capito *

Rana capito *

Rana cascadae * *

Rana chiricahuensis *

Rana clamitans *

Rana muscosa * *

Rana pipiens * * *

Rana pretiosa * *

Rana spp. *

Rana subaquavocalis *

Rana sylvatica *

Rana tarahumarae *

Rana utricularia *

Rana virgatipes * *

Rana yavapaiensis * *

Rhyacotriton olympicus *

Rhyacotriton variegatus * *

Scaphiopus bombifrons * *

Scaphiopus couchii * *

Scaphiopus hammondii * *

Scaphiopus holbrookii *

Scaphiopus holbrookii

 holbrookii *

Taricha torosa torosa * *

Typhlotrition spelaeus *

Total number of species/

 subspecies: 51 39 42 26

Number of genera: 14 12 17 14

1Species of conservation concern were defined from Vial

and Saylor (1993) and include those species with the

following status categories: Decline observed, federal or

state threatened and endangered, vulnerable, rare,

sensitive, regional concern, locally absent, extinct, federal

candidate species, state species of special concern, state

critical, state vulnerable, and candidate for state status.

Species with International Union for the Conservation of

Nature and Natural Resources (IUCN) categories of extinct,

extinct in the wild, critical, endangered, vulnerable, and

susceptible were also included.

Table 15 (Cont’d.)

 Pacific Rocky Pacific Rocky

 Species Coast Mountain North South Species Coast Mountain North South
54 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999

Flather, Brady, and Knowles Wildlife Resource Trends in the United States

ian species occurs in the southeastern United States (Currie

1991), it is somewhat of a surprise that there are not more

species with declining trends in the South.

Many factors have been hypothesized to explain the

declines in amphibians. Direct habitat destruction or

contamination have been implicated in several documented population declines (Petranka and others 1993;

Hecnar and M’Closkey 1996). As noted by Pechmann and

Wilbur (1994), there is little contention that habitat loss

and pollution are contributing agents, but the widespread

nature of declines and population reductions in less

disturbed areas point to broader environmental agents.

Acidification (Dunson and others 1992; Wissinger and

Whiteman 1992), ultraviolet-B radiation (Blaustein and

others 1994a), introduced predators (e.g., bullfrogs and

fish) (Fisher and Shaffer 1996), and pathogens (Blaustein

and others 1994b) have all been proposed as likely candidates. Still other researchers are proposing interactive

effects among these agents (Long and others 1995). While

it seems likely that many factors are contributing to the

decline in amphibians, the relative importance of each

factor will probably depend on species and locale. Furthermore, it is unlikely that determining causation in

amphibian declines will be resolved without long-term

monitoring and experimental manipulation (Blaustein 1994).

Imperiled Species

An estimated global extinction rate that appears to be

unprecedented in geological time (May 1990) has heightened concern for increasing rarity among the nation’s

biota. Moreover, this elevated extinction rate is being

attributed to the activities of humans rather than the

result of some calamitous natural disaster (Pimm and

others 1995). Traditionally, conservation efforts to slow

the loss of biodiversity have focused on species with few

remaining individuals under the assumption that they

are the most vulnerable to extinction (Sisk and others

1994). Consequently, rarity has been used as an important

criterion for identifying which species should be the focus

of conservation efforts.

The Endangered Species Act of 1973 (ESA) has epitomized this species-by-species conservation strategy

(Doremus 1991). The ESA and its subsequent amendments codified broad-ranging protection for all species,

plant or animal, encompassing species in immediate danger of extinction and species that may be threatened with

extinction in the foreseeable future. The rate at which

species are being listed as threatened and endangered has

raised concerns that the current single-species emphasis

to recovery will be overwhelmed by the sheer number of

species requiring protection.

Much of what is reviewed in this section represents an

update of Flather and others (1994). That report reviewed

species listing trends and the geographic distribution of

threatened and endangered species based on that set of

species that were listed as threatened or endangered as of

August 1992. Since that time, more than 360 species have

been added to the endangered species list. We reiterate

some of the past trends noted in Flather and others (1994)

for historical completeness, but also discuss those trends

that have manifested since that earlier report.

Recent trends in species listings

Over the last two decades the number of threatened

and endangered species annually listed has varied

greatly.15 During the 1981 and 1983 calendar years, there

was a net addition of only four species, while greater than

120 species were listed in 1994. Based on cumulative plots

of species listed since July 1976, we identified three

phases in the listing history (figure 31a).

Phase 1 (July 1976 to October 1979) was characterized

by episodes of listing activity. The first plant listings

occurred during phase 1 and the pulse of new listings

toward the end of this phase was primarily due to a mass

listing of cactus species that were threatened by domestic

and international commerce (USDI Fish and Wildlife

Service 1979). Overall, 94 species were added to the list

during this time period.

The 56-month phase 2 (November 1979 to July 1984) is

conspicuous by its inactivity. The paucity of new listings

is explained, in part, by 1978 amendments that required

both designation of critical habitat with due consideration to economic impact and numerous new stipulations

for hearings and local notice (Kohm 1991). Logistically,

these changes were burdensome and led to a very protracted process for evaluating the merits of listing proposals. A net gain of 38 species was observed during phase 2.

From August 1984 until the moratorium on species

listings in April 1995 (phase 3), the species listing rate

increased greatly with a total net addition of 651 species.

The increase can again be traced to ESA amendments

passed in 1982 and 1988 that were directed at expediting

the listing process (Kohm 1991). Plant species were listed

at twice the rate of animal species and comprised the

majority (55%) of the listed biota by the end of this listing

phase (figure 31a). The listing rate for vertebrates and

invertebrates was nearly equal. Fish species now dominate numerically among vertebrate taxa, and they have

been listed at a rate exceeding twice that of other vertebrates (figure 31b). Invertebrates comprised 13% of the

15 In July of 1976, the U.S. Fish and Wildlife Service initiated

publication of a technical bulletin to assist in information exchange among agencies and organizations involved or interested in the Endangered Species Program (USDI Fish and

Wildlife Service 1976). We used these technical bulletins to

chronicle shifts in the emphasis given to major taxa and

changes in species listing rates.
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999 55

Wildlife Resource Trends in the United States Flather, Brady, and Knowles

listed taxa and more clams were added (35 new species

listed) during this phase than any other animal taxon

except fish (figure 31c). Under the criterion of “numbers

listed,” these trends suggest a taxonomic shift away from

highly visible and charismatic species.

We don’t know whether the moratorium on species

listings that was passed by Congress in April 1995 (USDI

Fish and Wildlife Service 1995) marks the beginning of a

new phase. Early trends indicate that listing has resumed

at a rate consistent with pre-moratorium levels (figure

31a). The current backlog of species (238 species awaiting

final listing decisions, 182 candidate species awaiting

listing proposals [USDI Fish and Wildlife Service 1996])

could certainly sustain the pre-moratorium listing rate for

many years. Whether new listings will sustain that rate

observed during phase 3 will depend largely on congresFigure 31. Cumulative plots of the number of species listed as threatened or endangered from July 1976 - June 30, 1997 for (a)

plants and animals, (b) vertebrates, and (c) invertebrates (U.S. Fish and Wildlife Service Endangered Species Technical

Bulletins)

1100

1000

110

100

20

30

40

50

60

SpeciesSpecies

Species

Date

Date

Date

70

70

60

50

40

30

20

10

0

80

90

0

10

900

800

700

600

500

400

300

200

100

0

01JAN76

01JAN76 01JAN76

01JAN81

01JAN81 01JAN81

01JAN86

01JAN86 01JAN86

01JAN91

01JAN91 01JAN91

01JAN96

01JAN96 01JAN96

01JAN01

01JAN01 01JAN01

Phase1

All Taxa

Fish

Clams

Insects

Snails

Crustaceans

Arachnids

Birds

Mammals

Reptiles

Amphibians

Plants

Animals

April 1995

Moratorium

Phase 2 Phase 3

a.

b. c.
56 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999

Flather, Brady, and Knowles Wildlife Resource Trends in the United States

sional appropriations and the amendments that will shape

the ESA following the long awaited reauthorization.

Even in the absence of future listings, the present

number of threatened and endangered species exceeds

the capacity of the U.S. Fish and Wildlife Service to fully

implement the provisions of the Act (Smith and others

1993). This, along with inevitable interspecific conflicts

that surface when species are considered separately (Losos

1993), has raised the question of whether a broader

inspection of the ecology and recovery needs of multiple

species would improve the efficiency with which species

conservation can be achieved (Marcot and others 1994;

Committee on Scientific Issues in the Endangered Species

Act 1995).

Geographic patterns in species endangerment

One approach that has the potential to help achieve

multiple species recovery is to focus conservation efforts

in those areas where threatened and endangered species

are concentrated. In a study of 631 listed species that

occur in the conterminous United States, Flather and

others (1998) found that endangered species are concentrated in distinct geographic regions (figure 32a) including the southern Appalachians, coastal areas, and the arid

Southwest.

Geographic areas with a concentration of endangered

species, also called “hotspots,” were identified by Flather

and others (1998) using the criteria specified in Prendergast

and others (1993)—namely, an arbitrarily defined upper

percentile of sample units ranked by species counts. To

account for the disparity in county area across the United

States, counties were partitioned into “large-area” and

“small-area” sets at a threshold of about 910,000 acres.

This resulted in 45% of the conterminous United States

being categorized as large-area counties. This was done

because the alternative, a simple conversion to county

density, produced an eastern bias and concealed known

concentrations of endangered species in the arid southwest (Hallock 1991). Counties were then ranked within

these large- and small-area sets according to the number

of threatened and endangered species that occurred within

their boundaries. Endangerment hotspots were initially

located by mapping the top 5% of large- and small-area

counties (i.e., those counties where the greatest number of

listed species were found). The areal extent of hotspots

was then defined by the top 20% of counties that were also

contiguous to, or formed distinct physiographic clusters

with, those counties in the top 5%. A land resource

classification system developed by the USDA Soil Conservation Service (1981) was used to group those counties

that supported many endangered species into regions

that had similar climate, physiography, soils, vegetation,

and land use. This led to the identification of 12 hotspots

of high species endangerment (figure 32b). Of the total

hotspot area (estimated as the sum of the area of all

counties within defined hotspots), 40% occurs in the

Rocky Mountain region, 29% occurs in the Pacific Coast,

28% occurs in the South, and less than 2.5% occurs in the

North.

The endangered species inhabiting hotspots showed

varying degrees of biological similarity as defined by

taxonomic composition, prevalence of endemism, land

type associations, and factors contributing to species

endangerment. The listed species occurring within eastern coastal hotspots were characterized by relatively high

proportions of birds and reptiles (particularly nesting

marine turtles), were associated with forest and aquatic

habitats, and have been negatively impacted by human

development activities (e.g., residential and urban development, shoreline modification). Of the eastern coastal

hotspots, Peninsular Florida had the highest level of

endemism with 78% of the species having their distribution restricted to this hotspot. Endangered species located in the arid southwest hotspots were characterized

by high proportions of plants and fish, were associated

with rangeland and wetland habitats, and have been

impacted by extractive resource uses (e.g., grazing, mining, water diversion) and the introduction of exotic species. The California hotspots were distinguished from

other regions by the relatively high proportion of insect

fauna that are listed, high endemism (greater than 55%

across both regions), and a mixture of forest and rangeland habitat associates. Like the east coast, residential and

industrial development was the most common factor

contributing to species endangerment in California; however, the introduction of exotic species has also had a

major impact on listed species populations. For a more

detailed discussion of biological characteristics of endangerment hotspots see Flather and others (1998).

Apart from the biological characteristics shared by

species occurring within endangerment hotspots, the

geographic proximity of these regions to National Forest

System lands is also of interest (figure 33). Among eastern

hotspots, approximately 5% of the total hotspot area is

included in National Forest System lands. Among western hotspots the overlap is 17%. Hotspots where the

percentage of National Forest System lands exceeds 10%

includes the Southern Appalachians (11%), Northern California Coastal Mountains and Valleys (14%), Colorado

and Green River Plateaus (16%), Southern California

Mountains and Valleys (17%), Arizona Basin and Range

(23%), and Northern Pacific Coast Range and Valleys

(40%). Although the hotspots are defined at a very geographically coarse scale, this analysis of overlap does

indicate which endangerment regions are likely to be

influenced by management on the nation’s National Forests and Grasslands.

Mapping regions where many endangered species cooccur can be used to geographically identify those eco-
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999 57

Wildlife Resource Trends in the United States Flather, Brady, and Knowles

Figure 32. The geographic distribution of threatened and endangered species. The map

depicted in (a) shows counties in percentile classes after ranking both large- and small-area

counties (to account for differential county area) according to the number of threatened and

endangered species that occurred within their boundaries. The map depicted in (b) identifies

endangerment hotspots. Labels refer to endangerment regions as follows: NP=Northern

Pacific Coast Range and Valleys, NC=Northern California Mountains and Valleys,

SC=Southern California Mountains and Valleys, SB=Sonoran Basin and Range, CG=Colorado

and Green River Plateaus, AB=Arizona Basin and Range, GC=Gulf Coast Marsh and Prairie,

EG=Eastern Gulf Coast Flatwoods, SA=Southern Appalachians, PF=Peninsular Florida,

AC=Atlantic Coast Flatwoods, MA=Mid-Atlantic and Northern Coastal Plain (Flather and others

1998).

Percentile

None known

<40

40-80

80-95

>95

a.

b.

NP.

NC

SB

SC

AB

CG

GC

EG

PF

AC

SA

MA
58 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999

Flather, Brady, and Knowles Wildlife Resource Trends in the United States

logical systems that are subject to high levels of endangerment stress. Knowledge of where listed species are concentrated can guide where habitat protection efforts

(Orians 1993) or habitat conservation plans (Pulliam and

Babbit 1997) are likely to affect the greatest number of

imperiled species. Location alone, however, says little

about why listed species are concentrated where they are

and what population threats will have to be addressed by

recovery efforts. Geographic patterns of endangered species occurrence coupled with information on those factors

that have contributed to species endangerment are prerequisite to developing integrative conservation strategies (Falk 1990). They also help define characteristics of

species or environments that are susceptible to endangerment (Slobodkin 1986) and are thus a means of anticipating where species endangerment may be a problem in the

future.

Projections of endangerment hotspots

Hof and others (1998; 1999) combined the descriptive

geography of the preceding section with environmental

information (e.g., climate, human populations, land use

activities) across the conterminous United States for the

development of statistical models that yielded predictions of where future concentrations of endangered species may occur. Statistical models relating environmental

and land use characteristics to the density of threatened

and endangered plants and animals were generated from

a county-level data set. Because county area varies greatly,

county-level data were interpolated to a uniform grid

(3280 cells) across the conterminous United States. In an

effort to highlight areas where species endangerment

may be concentrated in the future, we used these statistical models, in conjunction with projections of human

populations, land use and land cover (i.e., agriculture,

rangeland, forest, urban, wetland, water), and resource

extraction (timber, beef cows, irrigation, and minerals) to

the year 2020 to project changes in the density of threatened and endangered species. For a detailed methodological discussion of model estimation and projections

see Hof and others (1998; 1999).

Geographic areas where threatened and endangered

plant and animal species are expected to increase, called

future hotspots, were determined by the criteria specified

by Prendergast and others (1993). The top 5% of grids

with the greatest increase in plant or animal species were

identified and mapped.

Future hotspots of plant species endangerment were

primarily concentrated in the Southern region (figure 34a).

Many of the areas where the greatest number of new plant

species are projected to occur are found in areas where

there is already a high concentration of listed species

(compare with figure 32a). However, there are new areas

of concentration projected to occur in the Southern Piedmont, the desertic mountains and basins of west Texas,

and the Edwards Plateau region of west-central Texas.

Future endangerment hotspots for animals are clearly

concentrated in the Pacific Coast region (figure 34b). The

greatest absolute increase is projected to occur in coastal

Washington and Oregon, the California Central Valley,

and the region defined by the upper Columbia Plateau

and Palouse Prairie in eastern Oregon and Washington.

These future hotspots in the Pacific Coast region tend to

emphasize areas where animal endangerment is currently a concern—the exception being the emergence of a

potentially new area of animal species concentration in

eastern Oregon and Washington.

Trends in Wildlife Use

How humans have valued wildlife resources has shifted

over time. Utilitarian and commodity-oriented valuations of wildlife that were dominant at the turn of the

century have declined over time, suggesting that Americans are broadening their attitudes toward wildlife (Kellert

1987, Gray 1993). This broader base of values held by the

public for wildlife indicate the growing importance of this

resource to human social and economic welfare. Based on

data from the most recent survey of hunting and wildlifeassociated recreation (USDI Fish and Wildlife Service and

USDC Bureau of the Census 1997), hunters alone spent

nearly 21 billion dollars on equipment and travel in 1996.

Similarly, wildlife viewers spent 29 billion dollars in 1996

to observe, feed, or photograph wildlife. Although these

direct expenditures are useful indicators of economic

impact (e.g., the contribution of wildlife-oriented recreation to local and regional economies), it does not quanFigure 33. Percent of hotspot area that occurs on National

Forest System lands. Hotspot codes are as defined in figure

32.

NP NC SC SB AB CG MA AC PF EG GC SA

0

10

20

30

40

50

Percent overlap with NFS lands

Western hotspots Eastern hotspots

40

14

17

6

23

16

0

4

1

6

0

11
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999 59

Wildlife Resource Trends in the United States Flather, Brady, and Knowles

Figure 34. Areas projected to have the greatest increase (i.e., upper 5% of all grids) in plant (a) and animal (b)

endangered species for each RPA Assessment region by the year 2020 (Hof and others 1999).

a.

b.

Percentile

Percentile

Upper 5%

Upper 5%
60 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999

Flather, Brady, and Knowles Wildlife Resource Trends in the United States

tify the net economic value of these activities to the

individual participant.

In the context of wildlife-oriented recreation, net economic value measures the dollar amount that individuals

would be willing to pay, over and above what they

actually spend, to participate in some activity (Loomis

1993). Net economic value is a better measure of economic

benefit to individuals than direct expenditures, and the

total value to society can be estimated by summing net

economic value across all individuals that participated

(Waddington and others 1994). Based on a 1991 survey of

people who participated in wildlife-associated recreation

(USDI Fish and Wildlife Service and USDC Bureau of the

Census 1993), the mean annual net economic value to each

deer hunter varied from $768 in Maryland to $168 in Iowa

(Waddington and others 1994). If we multiply the total

number of deer hunters in each state by the mean estimates of net economic value, then the total net economic

benefit to society attributable to deer hunting is estimated

to be $5.2 billion. Estimates of the net economic value to

wildlife observers were similar in magnitude, varying

between $766 in Indiana to $106 in North Dakota. Total

societal benefits associated with wildlife observation ($10.2

billion) are higher than deer hunting due to the greater

number of participants.

Apart from the socioeconomic benefits attributable to

wildlife resources, state wildlife agencies derive much of

their revenues for managing these resources from license

sales and excise taxes on firearms and ammunition. Consequently, the number of persons participating in wildlifeassociated recreation not only affects rural economies

and societal values but also affects state revenues for

managing those resources.

Hunting

Since 1955, trends in wildlife-oriented recreation activities have been monitored by the National Survey of

Fishing, Hunting, and Wildlife-Associated Recreation.

Although methods have evolved, the survey is one of the

oldest and most comprehensive recreation surveys that

permits the examination of long-term trends in hunting

participation by the American public. Because survey

methodology has changed over time, trend analyses require adjustments to make participation estimates comparable among survey years (see USDI Fish and Wildlife

Service and USDC Bureau of the Census 1997: Appendix B).

The number of hunters and the days spent hunting

peaked in 1975. Since that time the number of hunters has

Figure 35. Trends in (a) the number of persons, and (b) the number of days that persons (≥12 years

old) spent participating in recreational activities dependent on wildlife. Dashed lines represent extrapolated estimates of participation in hunting activities for 1991 and 1996 based on percentage changes

applied to 1985 estimates (USDI Fish and Wildlife Service and USDC Bureau of the Census 1993;

USDI Fish and Wildlife Service and USDC Bureau of the Census 1997). aTrend for nonconsumptive

participants was provided by Richard Aiken (pers. comm., USDI Fish and Wildlife Service, 1997).

bTrends in nonconsumptive days have not been adjusted for differences in survey methodology.

1950 1960 1970 1980 1990 2000

Year

0

100

200

300

400

500

Days of participation (thousands)

Total hunters

Small

game

Big game

Migratory bird

Nonconsumptive

1950 1960 1970 1980 1990 2000

Year

0

5

10

15

20

25

30

35

Persons (millions)

Small game

Total

hunters

Big game

Migratory bird

Nonconsumptive

a. b.

a

b
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999 61

Wildlife Resource Trends in the United States Flather, Brady, and Knowles

Table 16--Regional trends in the number of hunters and nonconsumptive users 16 years old and older (USDI Fish and Wildlife 

Service and USDC Bureau of the Census 1997). 

Big game Small game Migratory bird Nonconsumptive 

Region 1991 1996 Change (%) 1991 1996 Change (%) 1991 1996 Change (%) 1991 1996 Change (%) 

 ------------------------------------------------------------------------------------thousands---------------------------------------------------------------------------------------------- 

Total U.S. 

(% of population) 

10,745 

(5.7) 

11,288 

(5.6) 

543 (5.1) 7,642 

(4.0) 

6,945 

(3.4) 

-697 (-9.1) 3,009 

(1.6) 

3,073 

(1.5) 

64 (2.1) 29,999 

(15.8) 

23,652 

(11.7) 

-6,347 (-21.2) 

North 5,790 

(6.7) 

5,879 

(6.6) 

89 (1.5) 4,025 

(4.6) 

3,586 

(4.1) 

-439 (-10.9) 892 

(1.0) 

1,040 

(1.2) 

148 (16.6) 14,344 

(16.6) 

11,043 

(12.5) 

-3,301 (-23.0) 

South 3,648 

(6.2) 

4,041 

(6.2) 

393 (10.8) 2,574 

(4.3) 

2,262 

(3.5) 

-312 (-12.1) 1,494 

(2.5) 

1,493 

(2.3) 

-1 (-<1) 7,635 

(12.9) 

6,441 

(10.0) 

-1,194 (-15.6) 

Rocky Mountain 1,405 

(9.9) 

1,544 

(9.6) 

139 (9.9) 968 

(6.8) 

1,010 

(6.3) 

42 (4.3) 417 

(2.9) 

289 

(1.8) 

128 (-30.7) 2,951 

(20.8) 

2.488 

(15.4) 

-463 (-15.7) 

Pacific Coast 691 

(2.3) 

865 

(2.7) 

174 (25.2) 428 

(1.5) 

533 

(1.7) 

105 (24.5) 331 

(1.1) 

386 

(1.2) 

55 (16.6) 5,034 

(17.1) 

3,648 

(11.5) 

-1,386 (-27.5) 

Note: Detail does not add to total because of multiple responses. U.S. totals include responses from participants residing in the District of Columbia. 

remained relatively stable, while the number of days

spent hunting has declined by about 11% from 1975 to

1996 (figure 35 on facing page). Trends in total hunting,

however, hide the diverse trends associated with the type

of hunting. Participation in big game hunting has increased in every survey period since 1955. Over the entire

40 year period that the surveys have been conducted, the

number of big game hunters has increased by more than

210%. The number of days spent hunting big game has

increased at an even greater rate with more than a 570%

increase since 1955. The number of days devoted to

hunting big game species has increased to the point where

more days are spent hunting big game than any other

category of hunting. In contrast, the number of small

game hunters has declined at a nearly constant rate since

the mid-1970s. The number of persons participating in

and the number of days spent hunting small game have

both declined by nearly 40% from 1975 to 1996. Over the

same time period, there has been a similar proportionate

decline in migratory game bird hunters (-45%) and days

of participation (-37%); however, the most recent survey

period indicates slightly increasing participation levels in

migratory bird hunting.

Regional trends in the number of hunters were obtained by summing state-level estimates for those states

comprising each RPA Assessment region. Because statelevel numbers have not been adjusted for differences in

survey design, we were only able to examine the 1991 and

1996 surveys that share a common methodology. Shortterm regional hunter trends were consistent with the

national trends in most cases (table 16). Exceptions include small game hunters in the West and migratory bird

hunters in the Rocky Mountain region. The number of

small game hunters increased in both the Rocky Mountain and Pacific Coast regions, despite substantial national declines in small game hunters. The increased

number of small game hunters in the Rocky Mountains,

however, did not keep pace with overall population

growth resulting in a declining proportion of the population participating from 6.8 to 6.3%. Migratory game bird

hunters in the Rocky Mountain Region declined by 31%

compared to a 2% gain nationally.

Many factors influence hunting participation rates,

including wildlife population status, the availability of

places to hunt, human demographics, and socioeconomics.

The participation trends observed are consistent with

those expected given our previous review of population

status. The two most commonly sought big game species

are deer (95% of all big game hunters hunt deer) and wild

turkey (19% of big game hunters) (USDI Fish and Wildlife

Service and USDC Bureau of the Census 1997). The

populations of these species have been increasing substantially over the last 20 years. Conversely, many of the

species sought by small game hunters have been declining in some regions, which may discourage participation.

Changes in populations of harvested species, however,

do not explain entirely the trends in hunting participation. In 1996, 51% of all hunters hunted only on private

land, 17% hunted only on public land, and 30% hunted on

both public and private land (USDI Fish and Wildlife

Service and USDC Bureau of the Census 1997). Given the

importance of private land to hunters, access to private

lands has the potential to affect participation in hunting.

However, only 2.5% of hunters in 1996 who would have

liked to have hunted more indicated that access or too few

places to hunt was a constraint (USDI Fish and Wildlife
62 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999

Flather, Brady, and Knowles Wildlife Resource Trends in the United States

Service and USDC Bureau of the Census 1997). Far more

common reasons for not being able to hunt as much as one

would like were “family or work obligations” (66%) and

“not enough time” (29%). Lack of leisure time appears to

be a more influential factor in hunting participation rates

than restricted access. One must recognize, however, that

the reasons given for not participating more in hunting

only address the perspectives of those persons who hunted

in 1996; it does not provide insights into why people who

would like to hunt did not hunt at all in 1996.

Increasing costs associated with hunting also may be

reducing participation. In 1991, a total of 572,000 hunters

owned or leased land for hunting and spent on average

$5,267 per hunter (USDI Fish and Wildlife Service and

USDC Bureau of the Census 1993). The number of hunters

with expenditures for owning or leasing land grew to 1.4

million in 1996 (a 2.5 fold increase), yet the average

amount spent declined to $2,203 per hunter (USDI Fish

and Wildlife Service and USDC Bureau of the Census

1997). Trends observed for private land user fees show a

different pattern. Like those that bought or leased land for

hunting, the number of persons that paid private land

users-fees increased from 703,000 hunters in 1991, to

930,000 hunters in 1996. Unlike owning and leasing land,

the fees paid for private land access doubled from 1991 to

1996 (each hunter spent an average of $173 in 1991 compared to $348 in 1996). Clearly the number of hunters that

own, lease, or pay private access fees for hunting purposes has increased dramatically in the last five years.

Figure 36. Projected indexed trends (1995=100) in hunting

and nonconsumptive wildlife activities from 1995 to 2050

(Bowker and others 1999).

Table 17—Regional projections of participation in hunting

and nonconsumptive wildlife recreation from 1995 to 2050.

Estimates reflect the percent change over the 55-year period

(Bowker and others 1999).

Rocky Pacific

Activity North South Mountain Coast

Days of wildlife viewing 76 120 94 114

Wildlife viewing participants 40 86 70 77

Days of hunting 12 -30 22 -19

Hunting participants -1 -36 20 -36

Whether these costs are becoming prohibitive, and therefore reducing hunting participation rates, will require

further research. It is interesting to note, however, that

only 7% of those who hunted in 1996, and would have

liked to have hunted more, cited cost as a constraint

(USDI Fish and Wildlife Service and USDC Bureau of the

Census 1997).

In an effort to understand some of the demographic

and socioeconomic factors that influence a person’s decision on whether to participate in hunting, Bowker and

others (1999) developed empirical models of participation and recreation intensity (i.e., days of participation).

They found that the factors most associated with hunting

behavior were gender, race, and population density.

Males, whites, and persons living in rural settings are

more likely to hunt than females, nonwhites, or persons

living in areas with high population densities. Bowker

and others (1999) used these empirically estimated relationships to project hunting participation to the year 2050

based on projections of demographic and socioeconomic

model variables. Projected number of hunters and days of

hunting (figure 36) do not indicate any major deviation

from the historical trends observed in the last 15 years.

The number of hunters is expected to decline slightly

(11% decline from 1995 to 2050), a decline that is attributed to the increasing proportion of nonwhites in the

population, increasing human populations, and the associated decline in rural residents. The number of days

spent hunting by participants is projected to remain

relatively stable over the projection period (figure 36).

Regional projections do vary around the national pattern (table 17). The number of hunters is expected to

increase by 20% in the Rocky Mountain region, to remain

stable in the North, and to decline by 36% in the South and

Pacific Coast regions (Bowker and others 1999). The

number of days spent hunting is expected to increase in

both the Rocky Mountains and the North (22% and 12%,

respectively), and to decline in the South and Pacific

Coast (-30% and -19%, respectively).

1990 2000 2010 2020 2030 2040 2050

Year

50

75

100

125

150

175

200

225

Index

Days of wildlife viewing

Wildlife viewing participants

Days of hunting

Hunting participants
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999 63

Wildlife Resource Trends in the United States Flather, Brady, and Knowles

Nonconsumptive Wildlife Recreation

The number of people who take trips for the primary

purpose of viewing, feeding, or photographing wildlife is

substantial. In 1996, nearly 24 million people participated

in what is now being called wildlife watching (USDI Fish

and Wildlife Service and USDC Bureau of the Census

1997). Most nonconsumptive wildlife recreation involves

the simple observation of wildlife (97%). Substantially

fewer individuals photograph (51%) or feed (42%) wildlife on trips away from their residence. Recent historical

participation trends in this activity, however, appear to

contradict the conventional wisdom that nonconsumptive

activities dependent upon wildlife are becoming more

popular among U.S. citizens (Duffus and Dearden 1990).

Although the number of persons and days of participation increased through the 1980s, participation in this

activity appears to have declined substantially since 1991.

From 1991 to 1996, the number of nonresidential (activities taking place away from the residence) wildlife watchers declined by 21% and the number of days spent viewing wildlife away from the home declined by 8% (figure

35). Although it is more common to participate in

nonconsumptive recreation than to hunt, the rate of decline

in wildlife watching exceeds that of all types of hunting.

Trends by Assessment region also indicate declining

participation in wildlife viewing (table 16), but the magnitude of the decline does vary. The South and the Rocky

Mountain regions showed the least decline in the number

of persons participating in wildlife watching (both declined by nearly 16%). The North declined at a rate similar

to the national trend (-23%), while the Pacific Coast region

declined at the greatest rate (-27%). The reasons for these

declines is unknown but may be related to some of the

same issues that affect participation in consumptive recreational activities, namely a reduction in leisure time

available to devote to wildlife watching (see Goodale

1991; Schor 1991).

Projections of participation in nonconsumptive wildlife recreation indicate that wildlife watching is expected

to gain in popularity in the future. Both the number of

persons participating in wildlife viewing and the number

of days devoted to wildlife observation are expected to

increase substantially by 2050 (Bowker and others 1999).

The number of participants is projected to increase by

61%, while the number of days is projected to increase by

97% (figure 36). Gender (more women participate than

men) and age (greater participation among older age

classes) were significant predictors of participation in

wildlife viewing activities. The aging of the U.S. population over the next several decades is the main reason this

activity is expected to gain in popularity. Regional participation projections indicate that the South and Pacific

Coast are expected to see the greatest gains in the popularity of wildlife watching (table 17).

A comparison of recent participation trends and participation projections reveals a discrepancy between what

has occurred in the recent past and the expected future

with respect to nonconsumptive wildlife recreation. An

explanation for this discrepancy is likely multifaceted.

The historical trends and participation projections are

based on two different survey methodologies that vary in

their definition of nonconsumptive wildlife recreation.16

In addition, the recreation projections reported here were

based on cross-sectional (i.e., for one point in time) patterns of association between participation in various activities, and demographic and socioeconomic factors. As

a result, information concerning recent historical participation patterns are not factored into the projection modeling approach. Regardless of the reason, this discrepancy highlights the need for further research on what

motivates people to participate in nonconsumptive wildlife recreation activities.

Trapping

Although most persons participating in trapping do so

primarily for sport and wildlife appreciation rather than

income (USDI Fish and Wildlife Service 1988; Siemer and

others 1994), we discuss trapping as a commercial venture given that pelts are sold in the marketplace regardless of the personal motivations for participating in this

activity.

From 1970 to 1995, the number of trapping licenses sold

has peaked twice—once during the period 1979-1981 and

again in 1987, both at about 400,000 licenses (figure 37).

Although many trappers participate for recreational reasons, their participation is affected by pelt prices (figure

37). Peak license sales occurred following a rapid increase

in pelt prices (measured as the average across all species).

From 1978 to 1979, and from 1986 to 1987, average prices

rose in excess of 75%. After a period of relative high

license sales in the mid- to late-1980s, participation in

trapping has declined by nearly 60% from the peak in

1987. Concurrent with the drop in participation, average

pelt prices also dropped by 50%. The number of trappers

and average pelt price has remained relatively stable

during the 1990s at about 160,000 license holders and an

average pelt price of just over $20. An impending European Union ban on imported furs from animals caught in

leghold traps has the potential to further reduce price and

participation in trapping.17

16 M. Bowker, pers. comm., USDA, Forest Service, Southern

Research Station, 1998.

17 Unpublished report, Southwick Associates. 1993. An economic profile of the U.S. fur industry. Report on file at the Rocky

Mountain Research Station.
64 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999

Flather, Brady, and Knowles Wildlife Resource Trends in the United States

The relationship between pelt prices and participation

was also observed in a study of New York fur trappers by

Siemer and others (1994). They found that nature appreciation was the strongest motivation to trap and that

obtaining an income ranked low as a motivational factor.

However, among inactive trappers, which constitutes

about half of the license holders, low pelt prices were

cited as the most important factor explaining their

inactivity.

Regional patterns in trappers and price do not show

strong deviation from national trends (figure 37). Because

nearly half of all trappers reside in the North, the trends

observed in the North are most consistent with those

observed nationally. Peak prices in pelts that occurred in

the late-1970s was primarily an eastern phenomenon,

while the peak prices that occurred in the late-1980s is

attributed to prices observed in the western United

States.

Wildlife-Associated Recreation on National

Forest System Lands

Public lands in general, and National Forest System

(NFS) lands in particular, provide diverse opportunities

to wildlife recreationists. The National Forest System

comprises 191 million acres on 156 National Forests and

19 National Grasslands. Although concentrated among

western states, these lands are well distributed throughout the country. Because NFS lands are widely distributed (nearly all U.S. residents live within 300 miles of NFS

land [Hunt 1988]), they represent a valuable network for

supporting wildlife-associated recreational opportunities.

In 1996 nearly 50% of all hunters spent some time on

public lands and 30% of hunting days were devoted

entirely, or in part, to hunting on public lands (USDI Fish

and Wildlife Service and USDC Bureau of the Census

Figure 37. National and regional trends in trapping licenses and average pelt prices from 1971 to 1995 (R.G. Frederick, pers.

comm., Department of Experimental Statistics, Louisiana State University, 1997).

Pacific Coast

Rocky Mountain

North

South

National:

'70 '75 '80 '85 '90 '95

Year

0

50

100

150

200

250 Licenses (thousands) '70 '75 '80 '85 '90 '95

Year

0

50

100

150

200

250 Licenses (thousands)

'70 '75 '80 '85 '90 '95

Year

0

50

100

150

200

250 Licenses (thousands)

'70 '75 '80 '85 '90 '95

Year

0

50

100

150

200

250 Licenses (thousands)

'70 '75 '80 '85 '90 '95

Year

0

100

200

300

400

500 Licenses (thousands)

'70 '75 '80 '85 '90 '95

Year

0

20

40

60

80

100

120 Average price (1995 dollars)

'70 '75 '80 '85 '90 '95

Year

0

20

40

60

80

100

120 Average price (1995 dollars)

'70 '75 '80 '85 '90 '95

Year

0

20

40

60

80

100

120 Average price (1995 dollars)

'70 '75 '80 '85 '90 '95

Year

0

20

40

60

80

100

120 Average price (1995 dollars)

'70 '75 '80 '85 '90 '95

Year

0

20

40

60

80

100

120 Average price (1995 dollars)a
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999 65

Wildlife Resource Trends in the United States Flather, Brady, and Knowles

Table 18--Summary of participation and economic impact of hunting and nonconsumptive wildlife recreation on National 

Forest System lands in 1996 (Maharaj and Carpentera

 and USDI Fish and Wildlife Service and USDC Bureau of the Census 

1997). 

Hunting Nonconsumptive 

Region 

Days on National 

Forest System lands 

(x1,000) 

% of totalb

days 

Retail sales 

(x 1,000 dollars) 

Expenditures 

per person per day 

(dollars) 

Days on National 

Forest System lands 

(x1,000) 

% of Totalb

Days 

Retail sales 

(x 1,000 dollars) 

Expenditures 

per person per day 

(dollars) 

Total U.S. 27,797 10.8 2,111,387 76 53,014 16.9 2,135,445 40 

North 9,205 8.1 501,459 54 14,801 10.9 406,768 27 

South 7,338 7.2 469,551 64 13,584 16.6 594,755 44 

Rocky Mountain 6,366 25.5 646,518 102 11,696 26.9 554,918 47 

Pacific Coast 4,887 27.5 493,860 101 12,932 25.0 579,005 45 

a

Unpublished report, Maharaj, V.; Carpenter, J. 1999. 1996 economic impact of fishing, hunting, and wildlife-related recreation on National Forest lands. 

Report prepared by American Sportfishing Association for the USDA Forest Service’s Wildlife, Fish, and Rare Plants Staff. Washington, DC. b

Estimate of the percentage of days that are spent recreating on National Forest System lands relative to the total number of days spent hunting or participating 

in nonresidential nonconsumptive wildlife recreation. 

1997). In a recent examination of the 1996 National Survey

of Fishing, Hunting, and Wildlife-Associated Recreation,

Maharaj and Carpenter18 estimated that more than 10% of

the days spent hunting were spent on National Forest

lands—a percentage that varied from a low of just over

7% in the South to a high of 27.5% in the Pacific Coast

(table 18). Furthermore, hunting on National Forests was

estimated to generate about 2.1 billion dollars in retail

sales, with hunters spending an average of $76 per person

per day (table 18).

The proportion of nonresidential nonconsumptive wildlife recreationists that visited publics lands is much greater

than hunters. In 1996, nearly 85% of wildlife-watching

participants recreated on public land (USDI Fish and

Wildlife Service and USDC Bureau of the Census 1997).

Maharaj and Carpenter18 also observed an increased proportion of nonconsumptive wildlife participant on NFS

lands relative to hunters. In 1996 nearly 17% of the total

days spent viewing wildlife took place on National Forests with a low of nearly 11% in the North and a high of

nearly 27% in the Rocky Mountains (table 18). Although

the total retail sales attributed to wildlife viewing on

National Forests is about the same as that estimated for

hunters (2.1 billion dollars), the average expenditure per

participant per day was lower ($40) (table 18).

Conclusions

Our purpose here was to review recent trends in

wildlife resources, including habitats, populations, harvests, and users. The motivation for this review stems

ultimately from the legislated requirements specified in

the RPA. However, resource management philosophies

are undergoing a period of introspection and considerable thought is being directed toward the question of how

to incorporate sustainability concepts into resource management decisions (Lubchenco and others 1991; Costanza

and others 1992; Levin 1993; Holdgate 1994). Therefore,

we have also been motivated to present resource trend

information that is relevant to evaluations of sustainable management and ecosystem health. Clearly, a comprehensive evaluation of sustainability cannot be accomplished by looking only at wildlife resources. However,

because human land use activities affect the amount,

distribution, and quality of habitat, which affects the

distribution and abundance of animals, trends in wildlife

resource attributes do appear to reflect some properties of

ecosystem health.

Because wildlife resources are diverse, synthesis of our

resource trends is burdensome owing to the sheer number of habitat, species, and user groups discussed. Consequently, it is difficult to evaluate how the findings from

this report collectively relate to resource sustainability.

What is needed is an organizing framework around which

to summarize the results we present. That framework

18 Unpublished report, Maharaj, V.; Carpenter, J. 1999. 1996

economic impact of fishing, hunting, and wildlife-related recreation on National Forest lands. Report prepared by American

Sportfishing Association for the USDA Forest Service’s Wildlife,

Fish, and Rare Plants Staff. Washington, DC.
66 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999

Flather, Brady, and Knowles Wildlife Resource Trends in the United States

would include identifying a set of resource indicators that

would signal the health of wildlife resources. International efforts, coordinated by the United Nations, have

been initiated to develop a set of criteria and indicators for

the conservation and sustainable management of forest

ecosystems. As reviewed in Coulombe (1995), the United

States is currently participating in such an effort directed

at temperate and boreal forests through what is referred

to as the “Montreal Process.” An initial set of sustainability indicators was specified and agreed to by participating Montreal Process countries in a formal document

entitled the “Santiago Declaration” (so named because

agreement was reached at a meeting in Santiago, Chili, in

February 1995). Although the Santiago Declaration has

proposed an initial set of indicators for temperate and

boreal forests, the actual set of indicators that will be

monitored will vary from country to country and will

change based on scientific review. One of the difficulties

in indicator development is that the concepts of sustainability and ecosystem health lack strict definition. There

is little agreement on the set of measurable indicators that

will permit an unambiguous evaluation of whether human activities are diminishing system health or sustainability (Lélé and Norgaard 1996).

In the absence of a recognized set of wildlife indicators,

we have organized our findings around three, albeit ad

hoc, categories of resource condition. For each wildlife

resource attribute (i.e., habitat, population, harvest, and

users), we list those findings that we felt were indicative

of a favorable, uncertain, or unfavorable resource condition. Although many definitions of system health and

sustainability have been proposed (Dovers and Handmer

1993; Bertollo 1998), there is little consensus on those

evaluation criteria that would allow these concepts to be

implemented in resource planning (Gatto 1995; Lélé and

Norgaard 1996). In the absence of operational definitions

of system health and sustainability, our assignment of a

particular resource trend to a condition category was

necessarily subjective. An “unfavorable” resource condition was defined as those cases where recent historical

trends indicated severe rarity (of habitat or species) caused

by human activities or a trajectory toward rarity. We

defined historical resource trends as “favorable” if

they were recovering from an unfavorable state or if

current resource status was meeting long-term goals as

specified by managers. “Uncertain” resource conditions involved those where the empirical basis for

evaluating national and regional trends was inadequate

or there were conflicting resource trends that prevented assignment to either the favorable or degraded

condition classes.

In light of these resource condition definitions, the

“user of wildlife resources” attribute warrants some remarks. Humanity is a component of ecosystem structure

and function. In fact, most ecosystem dynamics cannot be

understood without accounting for human activities

(Vitousek and others 1997). Consequently, trends in human uses of wildlife can indicate if wildlife habitat or

populations are sufficient to meet human demands or if

there are shifts in how wildlife resources are valued by

the public. This can affect the economies of human

communities that offer wildlife-related goods and services to the public, which affects how land is used (e.g.,

intensive agriculture vs. natural area) and the focus of

wildlife management (e.g., hunting vs. wildlife observation).

A summary of how we interpreted recent wildlife

resource trends with respect to our resource condition

classes is provided in table 19. Notable favorable resource

trends include the stability of forest habitats in general;

recent gains in forested wetlands; recent improvement in

wildlife habitats associated with agriculture due to the

CRP; increases in big game, waterfowl, and some small

game species; breeding bird populations in general; and

participation in big game hunting. Unfavorable resource

situations that warrant management focus include an

imbalance in the mix of forest cover and age classes; the

high number of endangered rangeland ecosystems; wetland habitats; some small game and migratory game bird

populations; grassland nesting birds; and the increasing

number of species being added to the threatened and

endangered species list. Uncertain resource conditions

often were related to inadequate inventories including

rangeland condition; amphibian and furbearer population status; and mammalian small game species. Other

resource trends that we considered uncertain include

recent gains in agricultural and wetland habitats attributable to agricultural programs that may not continue in the

future; overabundance of certain big game and waterfowl

populations; declining participation in hunting and trapping; and trends in wildlife viewing, which has declined

recently but is projected to increase greatly in the

future.

Managing wildlife resources can become only more

challenging in the future as a growing human population

competes for the ecosystem goods and services that are

provided by forest and rangelands. Because the Forest

Service has resource stewardship responsibility for a

substantial portion of the nation’s land base (191 million

acres), it has the opportunity to shape the wildlife resource situation on National Forests and Grasslands in

the future. This opportunity also extends to cooperative

assistance programs on private lands and to the promotion of research within and outside the agency. This

Assessment has tried to provide a technical and objective

basis for identifying wildlife resource issues that should

be considered in the Forest Service’s strategic planning

process.
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999 67

Wildlife Resource Trends in the United States Flather, Brady, and Knowles

Table 19--Summary of wildlife resource attribute status. Numbers appearing parenthetically are a page number index. 

Resource condition 

Resource 

attribute Favorable Uncertain Unfavorable 

Habitat Forest area has remained 

stable for the past several 

decades. Commercial forest 

land has declined, but this was 

caused by conversion to special 

uses including wildlife habitat 

protection areas (4, 6). Most of 

this conversion occurred in the 

Rocky Mountain and Pacific 

Coast regions. 

Use of rangelands by livestock 

appears to be declining (12), but 

it does vary by Assessment 

region. Cattle numbers have 

increased in the Rocky 

Mountains and South since the 

last Assessment (12). 

Agricultural habitat quality

has increased recently due to 

the enrollment of highly erodible 

cropland into the Conservation 

Reserve Program (CRP)--with 

much of this conversion 

occurring in the Rocky Mountain 

region (4-5, 14, 17). 

Erosion rates have declined 

over the last decade nationally 

and in all Assessment regions 

(16). 

No net loss of wetlands in the 

Rocky Mountain region from 

1982 to 1992 (18) and an 

increase of forested wetlands

in the North (18). 

Forest cover types and age 

classes have shifted over time 

(7-9). Such shifts will benefit 

some species and harm others. 

Although rangeland area has 

declined recently (4, 9), there is 

a general lack of data that 

permitted an evaluation of range 

condition (9). Much of the 

decline in rangeland area has 

occurred in the South and 

Rocky Mountains (5). 

Land that has remained as 

cultivated cropland appears to 

be used more intensively. Farm 

size, nutrient inputs, and 

pesticide use have all increased 

(14-15), but there is little direct 

evidence concerning the 

impacts of these changes on 

wildlife at the national level. 

Wetland habitats have been 

lost at a declining rate because 

of agricultural programs (17-18). 

Whether those wetlands 

associated with agricultural 

lands uses will remain as 

wetlands in the future is 

uncertain and depends on the 

provisions of future Farm Bills 

and the economy. 

Forest cover type conversions 

that are of particular concern in 

the East are the loss of early 

successional (aspen-birch) and 

young age classes in the North, 

and the loss of pine and 

bottomland hardwoods in the 

South (7, 9). In the West, forest 

cover types that have declined 

by more than 25 percent include 

western white pine, larch, 

ponderosa pine, lodgepole pine, 

and redwood (7). 

There is a disproportionately 

high number of rangeland

ecosystems that are considered 

endangered including tall grass 

prairie and savanna habitats (9, 

12). 

More than half of the wetlands

that were present at colonial 

times have been lost (17). 

Although the rate of loss has 

declined over the last decade, 

wetlands continue to be 

converted, with much of the loss 

occurring in the South (18). 

Urban development has 

become the primary agent of 

wetland conversion (18-19). 

Forested wetlands declined in 

the South by 51,000 acres (18). 

Population/harvest Many big game species have 

shown increases in both 

population and harvests since 

the last Assessment (21, 23). 

Notable among these are deer, 

elk, wild turkey, black bear, and 

pronghorn. 

Some small game species, 

including ring-necked pheasant 

and cottontail, show some 

evidence of population 

increases that may be 

attributable to the CRP (25). 

Deer populations may be 

overabundant in some portions 

of their range (particularly the 

North) and represents an 

important issue that is now 

receiving management focus 

(22-23). 

Deer and wild turkey in the 

Rocky Mountain region show 

recent evidence of potential 

population and harvest declines 

(21, 23-24). 

Small game populations and 

harvests for those species 

associated with grassland, early 

successional, and farmland 

habitats have declined (25-28, 

29-30). Of particular concern 

are the trends in northern 

bobwhite (25, 29-30). 
68 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999

Flather, Brady, and Knowles Wildlife Resource Trends in the United States

Table 19 (Cont'd.). 

Resource condition 

Resource 

attribute Favorable Uncertain Unfavorable 

Population/harvest 

(Cont'd.) 

Trends in duck populations 

have increased substantially 

since the last Assessment (31). 

Populations of 6 of the 10 

principal duck species exceed 

those established for long-term 

planning (31-32). 

Duck harvests have shown 

recent gains, particularly in the 

Mississippi flyway (32-33). 

Nearly 80 percent of goose and 

swan populations are either 

increasing or stable (33). There 

have been record numbers of 

geese harvested since 1993--a 

pattern driven by the harvest 

levels in the Central and 

Mississippi flyways (34). 

About 75 percent of all 

breeding birds monitored had 

stable or increasing trends (44). 

The North had the greatest 

proportion of species with 

increasing trends (44). 

Mammalian small game

species are not monitored well, 

making it difficult to assess 

population status of these 

species (25-26). 

Small game species associated 

with forest habitats, including 

squirrel and forest grouse, show 

mixed trends (25). 

Recent increases in goose

populations may be exceeding 

the capacity of the breeding 

habitat (34). 

Mourning dove population 

trends have shown slight 

declines nationally (35). 

Population trends in furbearers

are not monitored well (39) and 

harvest appears to be driven by 

pelt price rather than population 

status (39). Thus it is difficult to 

evaluate the status of furbearer 

populations. 

There is preliminary evidence 

that the CRP may have 

increased grassland nesting 

bird populations in the Rocky 

Mountain region (44-45). 

There are numerous accounts 

of local declines in amphibian

populations, but in the absence 

of a national inventory it is 

difficult to assess the status of 

amphibian populations 

nationally (51-54). 

Populations of northern pintail

are a notable exception to duck 

population status. Populations 

have continued to decline and 

are now more than 70 percent 

below populations observed in 

the mid-1950s (31). 

Harvests of Canada geese in 

the Pacific flyway have 

remained stable while harvests 

in the Atlantic flyways have 

declined in the last decade (34). 

The only two populations of 

Canada geese with declining 

populations are the dusky and 

Atlantic populations, which 

occur in the Pacific and Atlantic 

flyways, respectively (33). 

In the Western management 

unit, mourning dove

populations have been declining 

at an average annual rate of 2.4 

percent since 1966 (35), and 

harvests have declined by more 

than 30 percent since the early 

1970s (38). 

Woodcock population indices 

appear to be declining at a 

more accelerated rate (37), and 

harvests have declined by more 

than 60 percent in the Eastern 

and Central management units 

(38). 

Grassland nesting birds as a 

group showed a high proportion 

(44 percent) of species with 

declining trends (44). More than 

70 percent of grassland 

nesting birds in the North and 

South have had long-term 

declines (45). 

Case studies of bird 

communities in the eastern 

United States indicate that 

landscapes under intensive land 

use (i.e., urban and agriculture) 

tended to have lower bird 

community integrity (48-49), a 

higher proportion of rare 

species (49), a higher 

proportion of 
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999 69

Wildlife Resource Trends in the United States Flather, Brady, and Knowles

Table 19 (Cont'd.) 

Resource condition 

Resource 

attribute Favorable Uncertain Unfavorable 

Population/harvest 

(Cont'd.) 

exotic individuals (50), and 

more variable species 

composition (i.e., high local 

extinction rates) (50-51) than 

landscape that supported 

greater amounts of natural 

vegetation. 

The rate at which species have 

been listed as threatened and 

endangered has increased 

greatly in the last 10 years (54-

55. Endangered species are 

concentrated along coastal 

areas, the arid Southwest, and 

the southern Appalachians (56-

58). 

Users of wildlife 

resources 

Participation in big game 

hunting has increased greatly 

since the mid-1950s (61). The 

greatest proportional gains in 

big game hunting from 1991 to 

1996 occurred in the Pacific 

Coast (+24 percent), followed 

by the South (+11 percent), and 

the Rocky Mountain region 

(+10 percent) (61). 

The number of migratory 

game bird hunters has 

declined substantially since the 

mid-1970s but shows evidence 

of rebounding during the 1990s 

(61). 

Hunting in general is declining 

in popularity (60-61). This trend 

appears to be caused by the 

dramatic decline in the number 

of small game hunters (61). 

This trend may reflect a decline 

in wildlife populations or a shift 

in recreational preferences. 

The number of trappers has 

declined substantially since the 

last Assessment and may be 

affected further by international 

agreements concerning the use 

of leghold traps (63). It is 

unclear whether this trend 

reflects a decline in furbearer 

resources or a change in 

human preferences. 

Participation in wildlife 

viewing has shown evidence of 

declining participation during 

the 1990s (63). The decline 

was greatest in the Pacific 

Coast and North (63). However, 

of all wildlife-dependent 

recreation activities, 

participation in nonconsumptive 

wildlife recreation is expected 

to increase at the greatest rate 

over the next 50 years (63). 
70 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999

Flather, Brady, and Knowles Wildlife Resource Trends in the United States

Acknowledgments

We would like to thank R. Max Peterson, Executive

Vice President of the International Association of Fish and

Wildlife Agencies, for coordinating our request to State

Wildlife Directors for population and harvest statistics on

selected game species. We are also grateful to the State

Wildlife Directors for their timely response and the comprehensive information provided by State agency biologists. We also thank John R. Sauer, USDI Geological

Survey, Biological Resources Division, Patuxent Wildlife

Research Center for providing us with an analysis of

recent trends in breeding bird populations. We appreciate the efforts of Rebecca G. Frederick, Department of

Experimental Statistics, Louisiana State University and R.

Greg Linscombe, Louisiana Department of Wildlife and

Fisheries in providing recent data on fur harvest statistics.

The manuscript benefited from reviews of earlier drafts

provided by: Bruce Marcot, Research Wildlife Biologist,

USDA Forest Service, Pacific Northwest Research Station; James E. Miller, President, The Wildlife Society;

Thomas M. Franklin, Wildlife Policy Director, The Wildlife Society; Richard L. Knight, Professor, Department of

Fishery and Wildlife Biology, Colorado State University;

Diane Eckles, Wetland Ecologist, Natural Resources Conservation Service; Noel Uri, Program Analyst, Natural

Resources Conservation Service; Dave Darr, Branch Chief,

Resource Valuation and Use Research, USDA Forest Service; and Linda Langner, Assessment Coordinator/Economist, Resource Program and Assessment, USDA Forest

Service.

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76 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999

Flather, Brady, and Knowles Wildlife Resource Trends in the United States

Plants

Alder, Red Alnus rubra

Ash Fraxinus spp.

Aspen Populus spp.

Beech Fagus grandifola

Birch Betula spp.

Cottonwood Populus spp.

Cypress Taxodium distichum

Elm Ulnus spp.

Fir Abies spp.

Fir, Douglas Pseudotsuga menziesii

Gum Nyssa spp., Liquidambar

 styraciflua

Hemlock Tsuga spp.

Hickory Carya spp.

Larch Larix spp.

Maple Acer spp.

Oak Quercus spp.

Oak, Live Quercus virginiana

Pine Pinus spp.

Pine, Jack Pinus banksiana

Pine, Loblolly Pinus taeda

Pine, Lodgepole Pinus contorta

Pine, Longleaf Pinus palustris

Pine, Ponderosa Pinus ponderosa

Pine, Red Pinus resinosa

Pine, Shortleaf Pinus echinata

Pine, Slash Pinus elliottii

Pine, Western White Pinus monticola

Pine, White Pinus strobus

Redcedar Juniperus virginianus

Redwood Sequoia sempervirens

Sagebrush, Big Basin Artemisia tridentata

 tritendata

Spruce Picea spp.

Spruce, Sitka Picea sitchensis

Birds

Bobwhite, Northern Colinus virginianus

Brant Branta bernicla

Canvasback Aythya valisineria

Chukar Alectoris chukar

Dove, Mourning Zenaida macroura

Gadwall Anas strepera

Goose, Canada Branta canadensis

Goose, Cackling Canada Branta canadensis minima

Goose, Dusky Canada Branta canadensis

 occidentalis

Goose, Greater White-fronted Anser albifrons

Goose, Ross’ Chen rossii

Goose, Snow Chen caerulescens

Grouse, Blue Dendropagus obscurus

Grouse, Ruffed Bonsa umbellus

Grouse, Sage Centrocercus

 urophasianus

Grouse, Sharp-tailed Pedioecetes phasianellus

Grouse, Spruce Canachites canadensis

Mallard Anas platyrhynchos

Partridge, Gray Perdix perdix

Pheasant, Ring-necked Phasianus colchicus

Pintail, Northern Anas acuta

Prairie-chicken, Greater Tympanuchus cupido

Prairie-chicken, Lesser Tympanuchus

 pallidicinctus

Quail, California Callipepla californica

Quail, Gambel’s Callipepla gambelii

Quail, Montezuma Cyrtonyx montezumae

Quail, Mountain Oreortyx pictus

Quail, Scaled Callipepla squamata

Redhead Aythya americana

Scaup Aythya spp.

Shoveler, Northern Anas clypeata

Swan, Tundra Cygnus columbianus

Teal, Blue-winged Anas discors

Teal, Green-winged Anas crecca

Turkey, Wild Meleagris gallopavo

Wigeon, American Mareca americana

Woodcock, American Scolopax minor

Mammals

Bear, Black Ursus americana

Beaver Castor canadensis

Bobcat Lynx rufus

Cottontail Sylvilagus spp.

Coyote Canis latrans

Deer Odocoileus spp.

Deer, Mule Odocoileus hemionus

Deer, White-tailed Odocoileus virginianus

Elk Cervus elaphus

Fox, Gray Urocyon cinereoargenteus

Fox, Red Vulpes vulpes

Hare Lepus spp.

Lynx Lynx canadensis

Mink Mustela vison

Muskrat Ondatra zibethicus

Pronghorn Antelocapra americana

Raccoon Procyon lotor

Squirrel Sciurus spp.

Appendix A: Scientific names of species mentioned in the text.

Common name Scientific name Common name Scientific name
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999 77

Wildlife Resource Trends in the United States Flather, Brady, and Knowles

Appendix B: Land use and land cover changes on nonfederal lands from 1982 to 1992 for the nation and each RPA

Assessment region. Entries in each table reflect the acres (x 1,000) that were converted from the 1982 land type specified by

the rows, to the 1992 land type specified by the columns. For example, in the first row of Table B.1, there were 365.8 million

acres of cultivated cropland in 1982. More than 80% of those acres that were cultivated cropland in 1982 remained cultivated in

1992 (295.7 million acres). Of the 70.1 million acres of cultivated cropland that were converted to another land use in 1992,

30.2 million acres were converted to CRP, 18.5 million acres were converted to noncultivated cropland, 11.2 million acres were

converted to pasture, 3.1 million acres were converted to urban, 2.5 million acres were converted to forest, and 1.7 million acres

were converted to rangeland. 1982 (acres X 1,000) 1982 (acres X 1,000)

Table B.1—Land use changes from 1982 to 1992 in the United States (USDA Natural Resources Conservation Service 1994).

1992 (acres X 1,000)

Cult. Noncult.

cropland cropland Pasture Range Forest Misc. Urban Water Federal CRP Total

Cult. 295,704.3 18,503.1 11,247.3 1,677.4 2,500.8 1,781.2 3,139.7 363.4 751.2 30,180.7 365,849.1

Noncult. 14,536.1 32,163.0 3,518.8 413.5 632.7 487.9 996.8 62.0 256.6 1,635.8 54,703.2

Pasture 7,816.3 3,976.1 104,011.1 1,475.2 8,161.5 1,379.3 2,405.5 317.5 302.3 1,252.0 131,096.8

Range 4,484.8 1,194.1 2,416.1 391,513.9 1,523.7 1,095.4 2,107.9 348.1 3,301.4 755.3 408,740.7

Forest 1,135.4 311.8 2,838.4 1,136.1 379,138.3 1,160.9 5,558.2 462.7 1,968.7 134.8 393,845.3

Misc. 850.4 327.3 808.0 270.7 1,425.5 48,349.6 290.8 103.2 268.7 79.4 52,773.6

Urban 216.1 34.8 84.7 90.7 216.6 21.6 77,424.9 2.1 0.7 0.3 78,092.5

Water 112.8 40.8 99.2 260.7 180.3 53.2 5.5 47,203.9 12.4 1.1 47,969.9

Federal 323.2 219.7 191.2 1,965.2 657.5 195.5 16.4 0 401,037.2 0.6 404,606.5

Total 325,179.4 56,770.7 125,214.8 398,803.4 394,436.9 54,524.6 91,945.7 48,862.9 407,899.2 34,040.0 1.938x106

%a 16.8 2.9 6.5 20.6 20.4 2.8 4.8 2.5 21.0 1.8 100.1d

%Changeb -11.1 +3.8 -4.5 -2.4 +0.1 +3.3 +17.7 +1.9 +0.8 nac na

aPercent of the total land base in 1992

b

Percent change from 1982 to 1992

c

Not applicable

d

Does not sum to 100 because of rounding

Table B.2—Land use changes from 1982 to 1992 in the North region (USDA Natural Resources Conservation Service 1994).

1992 (acres X 1,000)

Cult. Noncult.

cropland cropland Pasture Range Forest Misc. Urban Water Federal CRP Total

Cult. 109,062.9 9,026.6 2,919.3 0 355.3 747.0 1,287.5 90.1 87.1 6,506.4 130,082.2

Noncult. 7,572.4 12,956.1 1,641.6 0 390.2 306.3 377.1 18.3 21.7 875.7 24,159.4

Pasture 3,528.4 2,255.2 34,037.2 3.0 3,698.3 712.3 714.6 74.2 58.7 604.2 45,686.1

Range 8.1 7.4 10.1 123.4 18.3 1.2 0.6 0 0 0 169.1

Forest 328.6 168.2 664.6 0 142,788.8 511.4 1,834.0 113.3 355.1 46.9 146,810.9

Misc. 414.3 192.1 301.5 0 699.5 15,474.7 81.0 5.0 8.0 38.3 17,214.4

Urban 103.3 18.3 30.5 0 77.3 6.7 30,939.9 0.5 0.4 0.3 31,177.2

Water 35.3 11.2 22.5 0 51.8 15.7 0.5 14,435.1 0.4 0 14,572.5

Federal 28.5 11.2 12.8 0 79.5 2.2 0 0 15,290.3 0 15,424.5

Total 121,081.8 24,646.3 39,640.1 126.4 148,159.0 17,777.5 35,235.2 14,736.5 15,821.7 8,071.8 425,296.3

%a 28.5 5.8 9.3 <0.1 34.8 4.2 8.2 3.4 3.7 1.9 99.8d

%Changeb -6.9 +2.0 -13.2 -25.2 +0.9 +3.3 +13.0 +1.1 +2.6 nac na

aPercent of the total land lease in 1992

bPercent change from 1982 to 1992

c

Not applicable

dDoes not sum to 100 because of rounding
78 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999

Flather, Brady, and Knowles Wildlife Resource Trends in the United States 1982 (acres X 1,000) 1982 (acres X 1,000)

Table B.3—Land use changes from 1982 to 1992 in the South region (USDA Natural Resources Conservation Service 1994).

1992 (acres X 1,000)

Cult. Noncult.

cropland cropland Pasture Range Forest Misc. Urban Water Federal CRP Total

Cult. 76,370.9 2,589.0 6,427.8 763.0 2,127.0 578.9 1,257.4 197.4 275.6 8,100.1 98,687.1

Noncult. 1,030.1 5,260.1 875.7 47.5 219.8 59.7 297.2 26.1 46.4 97.6 7,960.2

Pasture 2,467.2 762.6 53,872.5 958.3 4,291.0 501.6 1,360.8 216.1 141.7 373.0 64,944.8

Range 1,041.2 153.8 1,520.4 110,074.3 758.5 296.7 941.7 204.3 202.1 218.1 115,411.1

Forest 769.1 124.6 2,100.4 140.3 168,902.5 534.2 3,189.7 309.1 766.8 84.4 176,921.1

Misc. 169.1 45.0 436.7 88.2 673.0 12,104.5 106.2 75.4 42.6 13.2 13,753.9

Urban 33.2 4.5 40.7 9.1 117.3 4.1 28,536.5 0 0.3 0 28,745.7

Water 30.0 5.4 49.1 50.1 107.7 17.4 3.1 20,148.5 5.5 1.1 20,417.9

Federal 19.0 3.6 32.8 4.3 137.6 0.6 0 0 24,492.8 0 24,690.7

Total 81,929.8 8,948.6 65,356.1 112,135.1 177,334.4 14,097.7 35,692.6 21,176.9 25,973.8 8,887.5 551,532.5

%a 14.9 1.6 11.8 20.3 32.1 2.6 6.5 3.9 4.7 1.6 100.0

%Changeb -17.0 +12.4 +0.6 -2.8 +0.2 +2.5 +24.2 +3.7 +5.2 nac na

aPercent of the total land base in 1992

bPercent change from 1982 to 1992

c

Not applicable

Table B.4—Land use changes from 1982 to 1992 in the Rocky Mountain region (USDA Natural Resources Conservation Service

1994).

1992 (acres X 1,000)

 Noncult.

cropland Cropland Pasture Range Forest Misc. Urban Water Federal CRP Total

Cult. 96,800.7 5,612.9 1,609.9 576.5 1.8 376.9 418.6 68.1 347.2 13,915.0 119,727.6

Noncult. 5,080.4 9,647.0 850.5 309.1 12.9 82.1 176.4 12.8 156.5 633.3 16,961.0

Pasture 1,583.4 780.7 12,262.3 399.5 43.2 76.7 178.2 20.0 67.3 270.8 15,682.1

Range 3,212.4 869.4 776.6 249,600.8 395.7 622.2 732.4 131.4 2,335.1 510.8 259,186.8

Forest 26.4 14.2 16.8 588.0 27,507.9 42.9 171.0 21.0 446.3 3.3 28,837.8

Misc. 229.2 66.3 49.4 156.3 33.0 14,495.5 61.7 7.8 137.9 27.9 15,265.0

Urban 70.2 10.0 11.0 73.4 13.9 1.9 11,116.6 1.6 0 0 11,298.6

Water 40.9 13.0 9.0 64.1 6.0 17.6 0 8,880.3 0.3 0 9,031.2

Federal 254.9 184.9 132.0 1,858.8 267.0 124.9 16.4 0 270,619.0 0.6 273,458.5

Total 107,298.5 17,198.4 15,717.5 253,626.5 28,281.4 15,840.7 12,871.3 9,143.0 274,109.6 15,361.7 749,448.6

%a 14.3 2.3 2.1 33.8 3.8 2.1 1.7 1.2 36.6 2.0 99.9d

%Changeb -10.4 +1.4 +0.2 -2.1 -1.9 +3.8 +13.9 +1.2 +0.2 nac na

aPercent of the total land lease in 1992

b

Percent change from 1982 to 1992

c

Not applicable

dDoes not sum to 100 because of rounding
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–33. 1999 79

Wildlife Resource Trends in the United States Flather, Brady, and Knowles 1982 (acres X 1,000)

Table B.5—Land use changes from 1982 to 1992 in the Pacific Coast region (USDA Natural Resources Conservation Service

1994).

1992 (acres X 1,000)

Cult. Noncult.

cropland cropland Pasture Range Forest Misc. Urban Water Federal CRP Total

Cult. 13,469.8 1,274.6 290.3 337.9 16.7 78.4 176.2 7.8 41.3 1,659.2 17,352.2

Noncult. 853.2 4,299.8 151.0 56.9 9.8 39.8 146.1 4.8 32.0 29.2 5,622.6

Pasture 237.3 177.6 3,839.1 114.4 129.0 88.7 151.9 7.2 34.6 4.0 4,783.8

Range 223.1 163.5 109.0 31,715.4 351.2 175.3 433.2 12.4 764.2 26.4 33,973.7

Forest 11.3 4.8 56.6 407.8 39,939.1 72.4 363.5 19.3 400.5 0.2 41,275.5

Misc. 37.8 23.9 20.4 26.2 20.0 6,274.9 41.9 15.0 80.2 0 6,540.3

Urban 9.4 2.0 2.5 8.2 8.1 8.9 6,831.9 0 0 0 6,871.0

Water 6.6 11.2 18.6 146.5 14.8 2.5 1.9 3,740.0 6.2 0 3,948.3

Federal 20.8 20.0 13.6 102.1 173.4 67.8 0 0 90,635.1 0 91,032.8

Total 14,869.3 5,977.4 4,501.1 32,915.4 40,662.1 6,808.7 8,146.6 3,806.5 91,994.1 1,719.0 211,400.2

%a 7.0 2.8 2.1 15.6 19.2 3.2 3.9 1.8 43.5 0.8 99.9d

%Changeb -14.3 +6.3 -5.9 -3.1 -1.5 +4.1 +18.6 -3.6 +1.1 nac na

aPercent of the total land lease in 1992

b

Percent change from 1982 to 1992

c

Not applicable

d

Does not sum to 100 because of rounding
The U.S. Department of Agriculture (USDA) prohibits discrimination in all its

programs and activities on the basis of race, color, national origin, gender, religion,

age, disability, political beliefs, sexual orientation, and marital or familial status.

(Not all prohibited bases apply to all programs.) Persons with disabilities who

require alternative means for communication of program information (Braille, large

print, audiotape, etc.) should contact USDA’s TARGET Center at 202-720-2600

(voice and TDD).

To file a complaint of discrimination, write USDA, Director, Office of Civil Rights,

Room 326-W, Whitten Building, 14th and Independence Avenue, SW, Washington,

DC 20250-9410 or call 202-720-5964 (voice or TDD). USDA is an equal opportunity provider and employer.

ROCKY MOUNTAIN RESEARCH STATION

RMRS

The Rocky Mountain Research Station develops scientific information and technology to improve management, protection, and use of

the forests and rangelands. Research is designed to meet the needs

of National Forest managers, Federal and State agencies, public and

private organizations, academic institutions, industry, and individuals.

Studies accelerate solutions to problems involving ecosystems,

range, forests, water, recreation, fire, resource inventory, land reclamation, community sustainability, forest engineering technology,

multiple use economics, wildlife and fish habitat, and forest insects

and diseases. Studies are conducted cooperatively, and applications

may be found worldwide.

Research Locations

Flagstaff, Arizona Reno, Nevada

Fort Collins, Colorado* Albuquerque, New Mexico

Boise, Idaho Rapid City, South Dakota

Moscow, Idaho Logan, Utah

Bozeman, Montana Ogden, Utah

Missoula, Montana Provo, Utah

Lincoln, Nebraska Laramie, Wyoming

*Station Headquarters, 240 West Prospect Road, Fort Collins, CO 80526
The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs

and activities on the basis of race, color, national origin, gender, religion, age, disability,

political beliefs, sexual orientation, and marital or family status. (Not all prohibited

bases apply to all programs.) Persons with disabilities who require alternative means for

communication of program information (Braille, large print, audiotape, etc.) should

contact USDA’s TARGET Center at (202) 720-2600 (voice and TDD).

To file a complaint of discrimination, write USDA, Director, Office of Civil Rights, Room

326-W, Whitten Building, 14th and Independence Avenue, SW, Washington, DC 20250-

9410 or call (202) 720-5964 (voice or TDD). USDA is an equal opportunity provider

and employer.
UNITED STATES DEPARTMENT OF AGRICULTURE

FOREST SERVICE

ROCKY MOUNTAIN RESEARCH STATION RMRS-GTR-33

GENERAL TECHNICAL REPORT

SEPTEMBER 1999