Conservation Buffer Distance Estimates for Greater SageGrouse—A Review

By Daniel J. Manier, Zachary H. Bowen, Matthew L. Brooks, Michael L. Casazza, Peter S. Coates, Patricia A. Deibert, 

Steven E. Hanser, and Douglas H. Johnson

Open-File Report 2014–1239

U.S. Department of the Interior

U.S. Geological Survey
ii

U.S. Department of the Interior

SALLY JEWEL, Secretary

U.S. Geological Survey

Suzette M. Kimball, Acting Director

U.S. Geological Survey, Reston, Virginia: 2014

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Suggested citation:

Manier, D.J., Bowen, Z.H., Brooks, M.L., Casazza, M.L., Coates, P.S., Deibert, P.A., Hanser, S.E., and Johnson, D.H., 

2014, Conservation buffer distance estimates for Greater Sage-Grouse—A review: U.S. Geological Survey Open-File 

Report 2014–1239, 14 p., http://dx.doi.org/10.3133/ofr20141239.

ISSN 2331-1258 (online)

Any use of trade, product, or firm names is for descriptive purposes only and does not imply 

endorsement by the U.S. Government.

Although this report is in the public domain, permission must be secured from the individual 

copyright owners to reproduce any copyrighted material contained within this report.
iii

Contents

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

Analytical Realities and Additional Background............................................................................................................. 2

Surface Disturbance ...................................................................................................................................................... 3

Linear Features ............................................................................................................................................................. 5

Energy Development ..................................................................................................................................................... 7

Tall Structures ............................................................................................................................................................... 8

Low Structures............................................................................................................................................................... 9

Activities (Without Habitat Loss).................................................................................................................................... 9

References Cited..........................................................................................................................................................10

Table

Table 1. Lek buffer-distance estimates for six categories of anthropogenic land use and activity ......................... 14
iv

Conversion Factors

Inch/Pound to SI

Multiply By To obtain

Length

foot (ft) 0.3048 meter (m)

mile (mi) 1.609 kilometer (km)

yard (yd) 0.9144 meter (m)

Area

acre 4,047 square meter (m2)

acre 0.4047 hectare (ha)

acre 0.004047 square kilometer (km2)

section (640 acres or 1 square mile) 259.0 square hectometer (hm2) 

square mile (mi2) 259.0 hectare (ha)

square mile (mi2) 2.590 square kilometer (km2) 

SI to Inch/Pound

Multiply By To obtain

Length

meter (m) 3.281 foot (ft) 

kilometer (km) 0.6214 mile (mi)

meter (m) 1.094 yard (yd) 

Area

square meter (m2) 0.0002471 acre 

hectare (ha) 2.471 acre

square kilometer (km2) 247.1 acre

square hectometer (hm2) 0.003861 section (640 acres or 1 square mile)

hectare (ha) 0.003861 square mile (mi2) 

square kilometer (km2) 0.3861 square mile (mi2)
1

Conservation Buffer Distance Estimates for Greater SageGrouse—A Review 

By Daniel J. Manier, Zachary H. Bowen, Matthew L. Brooks, Michael L. Casazza, Peter S. Coates, Patricia A. 

Deibert, Steven E. Hanser, and Douglas H. Johnson

Introduction

This report was prepared at the request 

of the U.S. Department of the Interior and is a 

compilation and summary of published 

scientific studies that evaluate the influence of 

anthropogenic activities and infrastructure on

Greater Sage-Grouse (Centrocercus 

urophasianus; hereafter, sage-grouse)

populations. The purpose of this report is to 

provide a convenient reference for land 

managers and others who are working to 

develop biologically relevant and 

socioeconomically practical buffer distances 

around sage-grouse habitats. The framework for 

this summary includes (1) addressing the 

potential effects of anthropogenic land use and

disturbances on sage-grouse populations, (2) 

providing ecologically based interpretations of 

evidence from the scientific literature, and (3) 

informing implementation of conservation 

buffers around sage-grouse communal breeding 

locations—known as leks.

We do not make specific management 

recommendations but instead provide 

summarized information, citations, and 

interpretation of findings available in scientific 

literature. We also recognize that because of 

variation in populations, habitats, development 

patterns, social context, and other factors, for a 

particular disturbance type, there is no single 

distance that is an appropriate buffer for all 

populations and habitats across the sage-grouse 

range. Thus, we report values for distances upon 

which protective, conservation buffers might be 

based, in conjunction with other considerations

(table 1). We present this information for six 

categories of land use or disturbance typically 

found in land-use plans which are representative 

of the level of definition available in the 

scientific literature: surface disturbance 

(multiple causes; immediate and cumulative 

influences); linear features (roads); energy 

development (oil, gas, wind, and solar); tall 

structures (electrical, communication, and 

meteorological); low structures (fences and

buildings); and activities (noise and related 

disruptions). Minimum and maximum distances 

for observed effects found in the scientific 

literature, as well as a distance range for 

possible conservation buffers based on 

interpretation of multiple sources, expert 

knowledge of the authors regarding affected 

areas, and the distribution of birds around leks

are provided for each of the six categories (table 

1). These interpreted values for buffer distances 

are an attempt to balance the extent of protected

areas with multiple land-use requirements using 

estimates of the distribution of sage-grouse 

habitat. Conservation efforts may then focus on 

the overlap between potential effect zone and 

important habitats. We provide a brief 

discussion of some of the most relevant 

literature for each category. References 

associated with the minimum and maximum 

values in table 1 are identified in the References 

Cited section with corresponding symbols.

Distances in this report reflect radii 

around lek locations because these locations are 

typically (although not universally) known, and 
2

management plans often refer to these locations. 

Lek sites are most representative of breeding 

habitats, but their locations are focal points 

within populations, and as such, protective 

buffers around lek sites can offer a useful

solution for identifying and conserving seasonal 

habitats required by sage-grouse throughout

their life cycle. However, knowledge of local 

and regional patterns of seasonal habitat use 

may improve conservation of those important 

areas, especially regarding the distribution and 

utilization of nonbreeding season habitats 

(which may be underrepresented in lek-based 

designations).

Analytical Realities and Additional 

Background

Understanding the effects of multiple 

human land uses on sage-grouse and their 

habitats is complicated by the combination of

environmental, ecological, and socioeconomic

conditions across the species range, which

includes parts of 11 U.S. States and 2 Canadian 

Provinces in western North America. Responses 

of individual birds and populations, coupled 

with variability in land-use patterns and habitat 

conditions, add variation in research results. 

This variability presents a challenge for land 

managers and planners seeking to use research

results to guide management and plan for sagegrouse conservation measures.

Variability between sage-grouse 

populations and their responses to different 

types of infrastructure can be substantial across 

the species’ range. Our interpretations attempt 

to encompass variability in populations (for 

example, migratory versus nonmigratory) and 

rangewide response patterns of sage-grouse to 

various human activities. Logical and 

scientifically justifiable departures from the 

“typical response,” based on local data and 

other factors, may be warranted when 

implementing buffer protections or density 

limits in parts of the species’ range. 

Natural movement behaviors of sagegrouse have been documented by multiple 

studies that provide direct evidence of inter- and 

intraseasonal movements from a few kilometers 

(km) (nonmigratory populations; Berry and 

Eng, 1985; Connelly and others, 2004) to 20–30

km or more (Connelly and others, 2004; Fedy

and others, 2012; Tack and others, 2012). An 

influential, telemetry-based, tracking project in 

central Montana indicated more than 90 percent 

of breeding season movements by male grouse 

were within 1.3 km (0.8 mi) of a lek and 76 

percent were within 1 km of a lek (0.6 mi; 

Wallestad and Schladweiler, 1974). The 1-km 

(0.6-mi) buffer used in many management 

efforts was based upon this research. More 

recent analyses have indicated that 90–95

percent of habitat use at the population level 

was focused within approximately 8 km (5

miles [mi]) of several California and Nevada lek 

sites (Coates and others, 2013), and 95 percent

of all nests were located within approximately 5

km (3.1 mi) of leks. Holloran and Anderson 

(2005) found that 64 percent of nests in 

Wyoming occurred within 5 km (3.1 mi) of 

leks, suggesting considerable protection of 

sage-grouse within these proximate habitats. In 

contrast, home ranges as large as 2,975 km2

(1,149 mi2

) have been documented (Connelly

and others, 2000, 2004) in some portions of the 

species’ range. These larger distances suggest 

that for some populations, the minimum 

distance inferred here (5 km [3.1 mi]) from leks 

may be insufficient to protect nesting and other 

seasonal habitats. Based on the collective 

information reviewed for this study,

conservation practices that address habitats 

falling within the interpreted distances may be 

expected to protect as much as 75 percent

(Doherty and others, 2010) to 95 percent

(Coates and others, 2013) of local population’s

habitat utilization.

Habitat condition, composition, 

structure, and distribution are important 

potential modifiers of the effect of human 

infrastructure and activities on sage-grouse 
3

populations (Dinkins and others, 2014; Walters 

and others, 2014). The distribution of sagebrush 

(Artemisia spp.) is a well-known biological and 

statistical predictor of sage-grouse response to 

their environment (for example, Connelly and 

others, 2004; Aldridge and Boyce, 2007; Hagen

and others, 2007; National Technical Team,

Sage Grouse, 2011; Wisdom and others, 2011;

Kirol and others, 2012; Beck and others, 2014; 

Smith and others, 2014). Differences among 

sagebrush communities within a population 

range may also affect the impact of 

infrastructure. For example, primary 

productivity of sites is typically greater in 

mountain big sagebrush (A. tridendata ssp. 

vaseyana) communities than Wyoming big 

sagebrush (A. t. ssp. wyomingensis) 

communities (Davies and Bates, 2010).

Sage-grouse depend on sagebrush, so 

buffer protections may be most effective when 

focused on avoidance of disturbance to 

sagebrush that provides the keystone to sagegrouse habitat. Important sage-grouse habitats

include those with >40 percent sagebrush 

landcover (within 5 km [3.1 mi] radial 

assessment area; Knick and others, 2013), 

sagebrush patch sizes greater than 1 km2 (0.4

mi2) (Aldridge and Boyce, 2007), and plot-level 

composition of approximately 10–30 percent

sagebrush cover and >15 percent grasses and 

forbs (Connelly and others, 2004; Stiver and 

others, 2006). Avoidance of activities that 

increase distance between sagebrush patches or 

that impose barriers to dispersal could also help 

maintain populations (Wisdom and others,

2011; Knick and Hanser, 2011).

Various protection measures have been 

developed and implemented, including 

complete closure of important habitats, distance 

buffers that restrict disturbing activities within 

designated distances, and developmentdisturbance density limits within habitats (for 

examples see, “Policy and Rules for 

Development” at http://utahcbcp.org/htm/tallstructure-info). Timing restrictions have also 

commonly been employed at lek sites, primarily 

to reduce disturbance to breeding sage-grouse.

Although specific details and implementation of 

these different approaches have varied, each 

approach has the ability (alone or in concert 

with others) to protect important habitats, 

sustain populations, and support multiple-use 

demands for public lands. As such, local and 

regional differences in design and 

implementation of conservation plans should be 

assessed with explicit attention to the details 

and cumulative impact of a suite of actions,

including but not limited to the buffer distances,

which are the focus of this report. 

Surface Disturbance 

Surface disturbance represents a

combination of human activities that alter or 

remove the natural vegetation community on a 

site. Isolating the potential effects of human 

land-use patterns on sage-grouse is challenging 

because causal factors are frequently 

interrelated and interactive (for example roads 

and distribution lines or roads and well pads) 

making a general discussion of “development 

effects” necessary. In cases where better 

discrimination is available, those specific types 

of surface disturbances are addressed in the 

following sections. The values in this section 

reflect a nondiscriminatory understanding of the 

independent and interactive and cumulative 

effects of activities that remove sagebrush cover 

and other natural vegetation, and often include 

continual and (or) intermittent activities, such as 

running motors and pumps, vehicle visits, and 

equipment servicing. The collective influence of 

human activity on the landscape, often referred 

to as the human footprint (Leu and others,

2008), has been associated with negative trends 

in sage-grouse lek counts (Johnson and others,

2011) and population persistence (Aldridge and 

others, 2008; Wisdom and others, 2011). A 

multiscale assessment of factors associated with 

lek abandonment between 1965 and 2007 found 

that the level of the human footprint within 5

km (3.1 mi) of the lek was negatively associated 
4

with lek persistence (Knick and Hanser, 2011). 

Agricultural activities, including tilling, 

seeding, and other highly managed activities,

are a component of the human footprint and 

clearly fall into the category of surface 

disturbance (removal of native vegetation);

however, agriculture is a special case because,

although agriculture occupies large areas with 

transformed conditions, these lands are typically 

privately owned and the habitat value of 

agricultural areas is not zero because these lands 

can provide cover and forage for some 

populations in some seasons (Fischer and 

others, 1996). For example, sage-grouse have 

been known to use agricultural lands in late 

summer and early spring (Fischer and others,

1996). Though we found no direct evidence for 

spacing recommendations between agricultural 

lands and leks or other sage-grouse habitat, the 

conversion of sagebrush to agriculture within a 

landscape has been shown to lead to decreased 

abundance of sage-grouse in many portions of 

their range (Swenson and others, 1987; Smith

and others, 2005; Aldridge and Boyce, 2007;

Aldridge and others, 2008). A potential 

mechanism for this decrease in abundances, 

besides the direct loss of habitat, is the 

association of generalist predators (Common 

Raven [Corvus corax] and Black-billed Magpie 

[Pica hudsonia]) with agricultural infrastructure 

(Vander Haegen and others, 2002) and 

subsequent predation on sage-grouse (Connelly

and others, 2004; Coates and Delehanty, 2010). 

Estimated distance effects were 

translated to a 5- to 8-km (3.1- to 5-mi) radius

around each lek to describe a possible 

conservation buffer area (interpreted range)

based on interpretation of two principal factors:

the potential effect area and the potential 

distribution of habitat use within affected areas.

The need for protection of populations that are 

not well understood requires some 

generalization, and this distance range is 

proposed because research suggests that a 

majority of sage-grouse distributions and 

movements (within and between seasons) occur 

within this range (for example, Berry and Eng,

1985; Lyon and Anderson, 2003; Holloran and 

Anderson, 2005; Walker and others, 2007; 

Aldridge and others, 2008; Knick and others,

2011; Naugle and others, 2011; Coates and 

others, 2013). Importantly, due to variability 

among individuals and populations, some 

individuals in most populations (migratory and 

nonmigratory) may move greater distances than 

those included in the buffer, but specific 

protections cannot, practically, be determined 

for all individuals and all behavioral patterns. 

Although leks are generally recognized as the 

center of breeding and nesting habitats, recent 

utilization distribution analyses have helped to 

refine understanding of sage-grouse habitat-use

patterns throughout the year. Based on this 

approach, Coates and others (2013) suggested 

that an 8-km (5-mi) protection area centered on 

an active lek location should encompass the 

seasonal movements and habitat use of 90–95

percent of sage-grouse associated with the lek. 

Longer distance movements are not always 

explicitly protected in this context, and habitats 

associated with previously unidentified leks 

may not be protected. However, final settling 

locations for more mobile individuals may be 

associated with quality habitats protected by 

buffers around adjacent lek sites. Furthermore, 

buffer distances beyond 8 km (5 mi) result in a 

decreasing benefit (cost-benefit trade-off) of 

increasing protection in areas that are less 

commonly used by sage-grouse. Without 

population-specific information regarding the 

location of habitats and movement of birds, 

which may be utilized when available (for an 

example see, Colorado Greater Sage-grouse 

Steering Committee, 2008), this generalized

protection area (circular buffer around active 

leks with radius of 8 km [5mi]) offers a 

practical tool for determining important habitat 

areas. (Note: the Colorado Plan [Colorado 

Greater Sage-grouse Steering Committee, 2008]

recommended a 6.4-km [4-mi] circular buffer,

which may be well suited for those populations 

and falls within the range identified here.)
5

Importantly, similar results and interpretations 

to those derived from California and Nevada 

populations (Coates and others, 2013) were 

attained from the eastern portion of sage-grouse 

range; namely, Holloran and Anderson (2005) 

reported 64 percent of monitored nests fell 

within 5 km (3.1 mi) of a lek, and response to 

industrial development (decreased nesting rates 

and success rates) was observable to distances 

between 5 and 10 km (3.1–6.2 mi) from a lek

suggesting that similar buffer distances are as 

relevant in Wyoming as in the Great Basin. In 

Utah, approximately 90 percent of nests (not all 

movements) were located within 5 km (3 mi) of 

a lek and threshold distance increased with 

greater contiguity of habitats. The smallest

effect distance (3.2 km [2 mi] from a lek) 

described by Naugle and others (2011) was 

previously described and tested in field research 

by Holloran and Anderson (2005) and Walker

and others (2007); these studies were designed 

to evaluate the effectiveness of existing 

stipulations. However, recent evaluation of 

different effect areas (Gregory and Beck, 2014) 

suggested significant immediate effects on lek 

attendance with one well pad within 2 km (1.2

mi) of a lek and time-lagged effects due to

industrial development within 10 km (6.2 mi) of 

a lek indicating a habitat within the 8 km (5 mi)

identified here may still experience an influence 

of development on some landscapes. Although 

considerable protections would be afforded by 

using a greater buffer distance from leks, 

research has indicated population effects are 

variable, and the cumulative effect of 

development may extend across the landscape

many kilometers (>10 km [6 mi]) beyond the 

immediately affected areas. Diminishing gain

analysis (Coates and others, 2013) suggested

that sustained gains from habitat protection 

(based on percent of highly used areas protected 

versus total area protected) diminished after 8

km (5 mi)(radius) from leks, which helped to 

establish a ceiling on interpretations for habitat 

buffers seeking to maximize conservation 

benefits and minimize impacts on land uses.

Linear Features

Roads, especially active roads such as 

collectors, major haul, and service roads, as well

as county, State, and Federal highways, create 

many of the same “aversion” factors described 

previously that are related to traffic noise on 

roadways and interactions with infrastructure 

associated with corridors (such as fences, poles, 

and towers). One potential mechanism behind 

road-aversion behavior by sage-grouse could be 

the intermittent noise produced by passing 

traffic. Blickley and others (2012) discovered 

that noise-disturbance simulations that 

mimicked intermittent sources (road noise), or 

separately, drilling noises (continuous),

generated a significant reduction in lek 

attendance of sage-grouse (73-percent reduction 

with road noise, 29 percent with drilling noise). 

Most planning related to linear features

applies to new construction, that is, avoidance 

of placing new roads or transmission lines in 

important habitats, but existing roads might also 

be addressed by considering seasonal closures, 

or removal, of roads within protective buffer 

areas. Fragmentation of habitats related to the 

network of roads and other linear features 

(potential for cumulative effects) may have 

negative effects on sage-grouse populations by 

reducing and fragmenting sagebrush habitat. 

When compared to extirpated leks, occupied 

leks have twice the cover of sagebrush (46

percent versus 24 percent) and ten times larger

average sagebrush patches (4,173 hectares [ha]

[10,310 acres] versus 481 ha [1,190 acres])

(Wisdom and others, 2011). However, it is 

important to recognize that previous 

assessments of relations between sage-grouse 

distributions and roads include a combination of 

positive and negative relations (Johnson and 

others, 2011), and local effects may be 

restricted to visible (or audible) range.

Correlations between the distribution of roads

with the distribution of quality sagebrush 

habitats (due to moderate topographic relief), 

interactions between influence of roads and 
6

infrastructure with topography and habitat 

conditions (visibility and audibility), and 

differences in traffic volumes may all contribute 

to population effects on sage-grouse; not all 

roads have the same effect (Carpenter and 

others, 2010; Dinkins and others, 2014).

Because roads and other linear features can 

have different effects on sage-grouse behavior, 

regional models of distributions and population 

dynamics have attempted to capture some 

differences; for example, roads closer to lek 

locations and other seasonal habitats may have 

greater effects than those occurring farther from 

important habitats (Hanser and others, 2011). 

Effects of pipelines and powerline corridors 

were tested but were not found to have clear, 

rangewide effects on lek trends (Johnson and 

others, 2011). However, it has become evident 

that interactions and co-location of linear 

features (for example, power distribution lines 

along roads and railroads) can make separation 

of effects difficult (Walters and others, 2014); 

power lines are addressed in a following section 

(Tall Structures).

Because of general concerns about 

habitat fragmentation and loss due to 

transportation networks, rangewide assessment 

of the effects of distributed human features, 

including road proximity (distance) and density,

on trends in sage-grouse populations (based on 

lek counts), were conducted (Johnson and 

others, 2011). Incremental effects of 

accumulating length of roads in proximity to 

leks were apparent rangewide, although limited 

to major roads (State and Federal highways and 

interstates). This effect was demonstrated by 

decreasing lek counts when there were more 

than 5 km (3.1 mi) of Federal or State highway 

within 5 km (3.1 mi) of leks and when more 

than 20 km (12.4 mi) of highway occurs within 

an 18-km (11.2-mi) window (Johnson and 

others, 2011). Regional assessments (sagegrouse management zones, MZs; see Stiver and 

others, 2006) indicated downward trends in 

northern Great Basin (MZ4 and a portion of 

MZ5) populations when road density within 

5-km (3.1-mi) radius of lek exceeded 30 km 

(18.6 mi). In Great Plains populations (MZ1), 

lek trends declined within a 10 km (6.2 mi)

radius of a major road. It is important to note 

that many of the regional assessments did not 

indicate decreasing lek trends associated with 

the various size-classes of roads that were 

assessed (Johnson and others, 2011). In separate 

analyses in Wyoming, probability of sagegrouse habitat use (based on pellet-count 

surveys) declined around major roads (State and 

Federal highways and interstates) when 

assessed using a 1-km (0.6-mi) exponential 

decay function (exp(distance /–1km); Hanser and 

others, 2011). Assessment of lek trends in 

proximity to a large, interstate highway (I-80) 

indicated that all formerly recorded lek sites

within 2 km (1.25 mi) of the highway were 

unoccupied, and leks within 7.5 km (4.7 mi) of 

the highway had declining attendance (Connelly

and others, 2004). 

Radio-telemetry (Very High Frequency, 

VHF) studies are often used to help track and 

document animal movements and habitat use, 

and some have reflected affinity of sage-grouse 

to roads (for example, Carpenter and others,

2010; Dinkens and others, 2014). However, this

pattern may be due to search patterns employed 

by road-bound investigators (Fedy and others,

2014) or the distribution of roads across quality 

habitats in flat and lower elevation terrain

(Carpenter and others, 2010; Dinkins and 

others, 2014) as opposed to selection of roads as 

preferred habitats. Seasonal, Statewide habitat 

models in Wyoming indicated a difference in 

seasonal sensitivity to density of paved roads,

suggesting a decaying effects function 

approaching zero as distance approaches 3.2 km 

(2 mi) of leks (negative exponential) during the 

nesting and summer seasons, and a decay 

function approaching zero as distance 

approaches 1.5 km (0.9 mi) of leks during 

winter (Fedy and others, 2014). However, 

Dinkins and others (2014) found decreased risk 

of death for hens with increasing road density, 

but they also noted that the co-location of road 
7

distribution and quality habitat may have 

influenced this result. Although noise has been 

clearly demonstrated to influence sage-grouse 

(Blickley and others, 2012), the influence of 

individual roads or networks of roads on sagegrouse habitat use and demographic parameters 

remains a research need. This is a good example 

of the challenge associated with making clear 

interpretations of the effect area (and therefore, 

a definitive buffer distance) for these types of 

infrastructure. 

Energy Development

Research and applications addressing 

surface disturbances in sagebrush ecosystems 

have been commonly conducted in relation to 

energy development activities. Lands affected 

by these activities have been the focus of many 

studies investigating the effects of 

anthropogenic activities on sage-grouse 

behavior and population dynamics, so the 

previous section (Surface Disturbance) contains 

much of the information relevant here.

Direct impacts of energy development 

on sage-grouse habitats and populations, such as 

loss of sagebrush canopy or nest failure, have 

been estimated to occur within a 1.2-ha (3-acre) 

area of leks (radius: 62 m [68 yards]); indirect 

influences, such as habitat degradation or 

utilization displacement, have been estimated to 

extend out to 19 km (11.8 mi) from leks 

(Naugle and others, 2011). Regional analyses of 

well-density and distance effects (Johnson and 

others, 2011) suggested negative trends in 

populations (lek counts) when distance was less 

than 4 km (2.5 mi) to the nearest producing 

well; whereas density effects were evident 

rangewide based on decreasing population 

trends when greater than eight active wells 

occurred within 5 km (3.1 mi) of leks, or when 

more than 200 active wells occurred within 18

km (11 mi)of leks. In Wyoming, significant 

negative relations between use of seasonal 

habitats and well densities have been 

demonstrated. Fedy and others (2014) found a 

significant negative relation between well 

density and probability of sage-grouse habitat 

selection during nesting (3.2-km [2-mi] radius) 

and winter (6.44-km [4-mi] radius) seasons. In 

the Powder River Basin, wintering sage-grouse 

were negatively associated with increasing

coalbed natural gas well densities within a 2-km 

× 2-km (1.24-mi × 1.24-mi) window (Doherty 

and others 2008). Also, Gregory and Beck 

(2014) documented lek attendance decline when 

energy development averaged 0.7 well

pads/km2 (1.81 well pads/mi2

; using a 10-km ×

10-km [6.2-mi × 6.2-mi] assessment window) 

across multiple populations and different 

development patterns.

A key consideration, besides the impacts 

of the development footprint on habitat 

condition and predation potential, is the effect 

of intermittent noise on behavior (avoidance) as 

evident from work by Blickley and others 

(2012) who found decreased lek activity due to 

mimicked drilling and road noise produced at 

close range (volume level equivalent to a road 

or well 400 m [1300 ft] away). A precise 

distance for noise effects has not been 

determined, but this value likely varies 

depending on the source (equipment, vehicles) 

and the terrain.

Less information is available about the 

effects of renewable energy development, such 

as wind-turbine arrays, on sage-grouse. LeBeau

and others (2014) monitored effects during 

breeding season (95 nests and 31 broods) and 

found a linear decline of 7.1 percent in nest 

failure and 38 percent in brood failure with each 

1-km (0.6-mi) increase in distance from wind 

energy infrastructure (less effect with greater 

distance). Changes in mortality were not 

attributed to direct collisions but to increased 

predation. It is notable that one study on prairie 

chickens (a related galliform, Tympanuchus 

cupido) found increased nest success rates 

adjacent to recent wind-energy facilities 

(Winder and others, 2014).

Suggestions that sage-grouse 

instinctively avoid wind turbines (tall 
8

structures) to avoid predators are debated 

because of the difficulty in directly connecting 

predation risk to infrastructure, which often 

includes a combination of features (Walters and 

others, 2014). A further discussion of this topic 

is contained in the Tall Structures section 

below. It is notable that use of wind turbines as 

perches has not been documented. 

Tall Structures 

It is important to recognize that the 

effect of tall structures remains debated, and this 

category contains a wide array of infrastructure 

including poles that support lights, telephone

and electrical distribution, communication 

towers, meteorological towers, and high-tension 

transmission towers. Determining effects of 

these structures has remained difficult due to 

limited research and confounding effects (for 

example, towers and transmission lines are 

typically associated with other development 

infrastructure; Messmer and others, 2013; 

Walters and others, 2014). Lacking precise 

information regarding the influence of tall

structures on the foraging behavior of corvids 

and raptors, management plans have adopted 

similar buffer distances to other infrastructure, 

for example a 1-km (0.6-mi) buffer of 

avoidance around lek sites. The general 

assumption is that these structures offer 

opportunities for increased predator use and 

thereby generate aversion behaviors among prey 

species (that is, sage-grouse); however, other 

effects, such as electro-magnetic radiation, have 

not been eliminated, and effects on predation 

rates have not been confirmed (Messmer and 

others, 2013). Habitat alteration, akin to other 

linear features (see previous section), may also 

be considered an important component of 

interactions between powerline corridors and 

sage-grouse populations. The 1-km (0.6-mi)

buffer indicated here (table 1) was based upon 

Wallestad and Schladweiler (1974) who 

observed that more than 90 percent of breeding 

season movements by male grouse were within 

1.3 km (0.8 mi) of a lek (76 percent of 

movements occurred within 1 km [0.6 mi]).

Subsequently, Connelly and others (2000, p. 

977) suggested, "avoid building powerlines and 

other tall structures that provide perch sites for 

raptors within 3 km of seasonal habitats... lines 

should be buried or posts modified to prevent 

use as perches...” Recent research has added 

important information to previous speculations 

and estimations, specifying concentrated 

foraging behaviors by common ravens (a 

common predator of sage-grouse nests) at 2.2

km (1.4 mi) from electrical transmission towers 

with the observed foraging area extending out to 

11 km (6.8 mi; Coates, and others, 2014a). 

According to estimates, the greatest potential 

impact on sage-grouse nests occurs within 570

m (0.35 mi) of structures (Howe and others,

2014). Negative trends in lek counts were 

associated with increasing number of 

communication towers within 18km of leks 

range wide (Johnson and others 2011). Johnson

and others (2011) also documented negative 

trends in lek counts for Great Plains populations 

within 20 km (12.4 mi) of a power transmission 

line or when the linear density of powerlines 

within 5 km (3.1 mi) of leks was greater than 10

km (6.2 mi)—notably, affected areas may be 

greater in these habitats (compared to other 

intermountain communities) because visibility 

is often greater in gentle terrain.

Although considerable attention has 

been paid to the influence of tall structures 

(both anthropogenic and trees) on the quality of 

sage-grouse habitat (for example, Connelly and 

others, 2000; Connelly and others, 2004; Stiver

and others, 2006; National Technical Team,

Sage-Grouse, 2011; Manier and others, 2013),

solid evidence that sage-grouse instinctively 

avoid tall structures to avoid predators remains

debated because of the difficulty in connecting 

predation risk to various combinations of 

infrastructure (Walters and others, 2014). 

However some evidence exists; in Wyoming the 

risk of death for sage-grouse hens was greater 

near potential raptor perches (Dinkins and 
9

others, 2014), and in Idaho common raven 

abundance was greater near energy 

infrastructure (2.2 km [1.4 mi]; Coates and 

others 2014a,b). Coates and others (2014b)

found different effects of infrastructure on three 

species of raptor (Buteo spp.) and common 

ravens, with clear increases in raven abundance 

with infrastructure but less consistent results 

with raptors. Also, in Wyoming, common raven 

habitat use was greatest within 3 km (1.8 mi) of 

human activity centers, and raven occupancy 

was correlated with nest failure (Bui and others,

2010). These studies suggest a potential 

increase in predators of sage-grouse, in 

particular ravens, which may influence 

predation pressure more than raptors. 

Low Structures 

Collisions of flying sage-grouse with 

fences have been associated with mortality 

(Beck and others, 2006; Stevens and others,

2012a,b). Incidents were focused within 1.6–3.2

km (1–2 mi) of leks on flat to rolling terrain and 

fences with wide spacing of poles and (or) less

visible ‘t-posts’ (as opposed to wooden posts) 

(Stevens and others 2012a,b). Importantly, the 

effect of fences was apparently less in rougher 

terrain, presumably due to differences in flight 

behaviors in the birds. Marking fences helps 

flying grouse avoid these collisions; therefore, 

marking or removal of fences within 2 km (1.2

mi) of leks on flat or rolling terrain can reduce 

sage-grouse mortality associated with collisions.

In a review of previous research, including 

theses and reports, Connelly and others (2004, 

p. 4–2) described findings of Rogers (1964) 

who stated that only 5 percent of leks were 

found within 200 m (656 ft) of a building, 

which suggests structures, even without regular 

activity and (or) noise, may have produced 

aversion behavior in historic sage-grouse

populations. Recent research provides evidence 

that ravens forage at distances as far as 5.1 km 

(xx mi) from buildings in sagebrush 

environments (Coates and others, 2014a)

suggesting that a wide distribution of 

infrastructure that can supply nesting or resting 

sites for ravens could have negative effects on 

sage-grouse populations.

Activities (Without Habitat Loss)

Tests using recorded noises and wild 

sage-grouse populations (Blickley and others,

2012) suggest that loud noises transmitted at 

decibels (70 dB at 0 m; 40 dB at 100 m [328 ft])

to approximate a noise source 400 m (1300 ft) 

from leks caused decreased activity on leks. 

Though they did not test the range of potential 

noise volumes or activities (different noises)

associated with recreation or other 

(nonindustrial) activities, this research is our 

best evidence of the effect of noise (independent 

from infrastructure) on sage-grouse behavior. 

The upper limit (4.8 km [3 mi]) is the value 

being used by the State of Nevada for reducing 

noise effects on sage-grouse due to locations of 

geothermal energy facilities (Nevada 

Governor’s Sage-Grouse Conservation Team,

2010). Better understanding of the type, 

frequency, and volume of noise effects on sagegrouse behavior will enhance our ability to 

define effect areas.
10

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ISSN 2331-1258 (online)

http://dx.doi.org/10.3133/ofr20141239
14

Table 1. Lek buffer-distance estimates for six categories of anthropogenic land use and activity. Literature 

minimum and maximum values are distances for observed effects found in the scientific literature. Interpreted 

ranges indicate potential conservation buffer distances based on multiple sources. [Citations for literature minimum 

and maximum values are denoted using corresponding symbols in the References Cited section.]

Category Literature minimum Interpreted range (lower) Interpreted range (upper) Literature maximum

Surface disturbance 3.2km (2mi) * 5km (3.1mi) 8km (5mi) 20km (12.4mi) ◊

Linear features 400m (0.25mi) ‡ 5km (3.1mi) 8km (5mi) 18km (11.2mi) ◊

Energy development 3.2km (2mi) ǂ 5km (3.1mi) 8km (5mi) 20km (12.4mi) ◊

Tall structures 1km (0.6mi) ° 3.3km (2mi) 8km (5mi) 18km (11.2mi) ◊

Low structures 200 m (0.12 mi) § 2 km (1.2mi) 5.1 km (3.2mi) 5.1 km (3.2mi) «

Activities 400 m (0.12 mi) ‡ 400 m (0.12 mi) 4.8 km (3mi) 4.8 km (3mi) ψ