Appendix G: Biological Assessment 

Appendix G: Biological Assessment 

G.1 INRODUCTION 

The following is the biological assessment (BA), and cover letters to the USDI Fish and 

Wildlife Service, for Terrestrial Wildlife Species for the Custer National Forest Sioux 

Travel Management Final Environmental Impact Statement.

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Appendix G: Biological Assessment 

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Appendix G: Biological Assessment 

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Appendix G: Biological Assessment 

BIOLOGICAL ASSESSMENT 

FOR 

TERRESTRIAL WILDLIFE SPECIES 

Sioux Travel Management 

Sioux Ranger District 

Custer National Forest

Prepared By: 

____/s/ Thomas Whitford ________ ________9/3/2008_____ 

Thomas Whitford – Forest Biologist Date 

Reviewed By: 

_____/s/ Mark Slacks ___________ ________9/8/2008_____ 

Mark Slacks – Environmental Coordinator Date 

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Appendix G: Biological Assessment 

SUMMARY

Determination of Effects

Implementation of the proposed Federal action would be a may affect but is not likely to 

adversely affect the Black-footed Ferret. 

Consultation Requirements

In accordance with the Endangered Species Act (ESA), its implementation regulations, 

and FSM 2671.4, the Custer National Forest is required to request written concurrence 

from the United States Fish and Wildlife Service (FWS) with respect to determinations of 

potential effects on Black-footed Ferrets on this area of the Forest. 

Need For Re-Assessment Based on Changed Conditions

The Biological Assessment findings are based on best available data and scientific 

information available. A revised Biological Assessment must be prepared if: (1) new 

information reveals affects which may impact threatened, endangered, and proposed 

species or their habitats in a manner or to an extent not considered in this assessment; (2) 

the proposed action is subsequently modified in a manner that causes an affect which was 

not considered in this assessment; or (3) a new species is listed or habitat identified which 

may be affected by this action. 

INTRODUCTION

The purpose of this Biological Assessment is to review the possible effects of the 

proposed federal action on threatened, endangered, and proposed species and their 

habitats. Threatened, endangered, and proposed species are managed under the authority 

of the Federal Endangered Species Act (PL 93-205, as amended) and the National Forest 

Management Act (PL 94-588). Under provisions of the Endangered Species Act (ESA), 

Federal agencies shall use their authorities to carry out programs for the conservation of 

listed species, and shall insure any action authorized, funded, or implemented by the 

agency is not likely to: (1) adversely affect listed species or designated critical habitat; (2) 

jeopardize the continued existence of proposed species; or (3) adversely modify proposed 

critical habitat (16 USC 1536). 

This biological assessment analyses the potential effects of the proposed action on all 

threatened, endangered, and proposed species known or suspected to occur in the 

proposed action influence area (Table 1). This species list was verified in March 2008 

(US Fish and Wildlife Service 2008). 

Table 1. Threatened, Endangered, and Proposed Species Known or Suspected to Occur 

Within the Influence Area of the Proposed Action. 

Species Status Occurrence 

Black-footed Ferret (Mustela nigripes) Endangered Not Present 

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Appendix G: Biological Assessment 

The bald eagle was determined to be recovered and was delisted effective August 8, 

2007. Consultation on effects of proposed Federal actions on this species is therefore no 

longer required. Verbal concurrence with the effects determination for Black-footed 

Ferret was received from Lou Hanebury of the U.S. Fish and Wildlife Service on July 24, 

2008. Copies of this BA will be sent to the USFWS Montana State Office and South 

Dakota State Office for written concurrence. 

PROPOSED PROJECT

The Sioux Ranger District of the Custer National Forest proposes to designate a system 

of roads and trails on the District for motorized public use. The Proposed Action consists 

of designating a system of motorized routes that provides the public with motorized 

recreation opportunities, while addressing resource concerns, recreation opportunity 

concerns, and/or reducing the potential for vandalism of improvements. Each system and 

non-system route was evaluated based on administrative, utilization (including 

recreation), resource, and protection needs and concerns to determine the disposition of 

the route. In compliance with the 2005 Motorized Travel Rule guidance, this alternative 

does not include designation of any routes for which the Forest Service does not have a 

legal right-of-way for public use. 

In general, primary travelways included in this alternative would be designated as roads, 

or where appropriate, as mixed motorized use roads, and all other routes would be 

designated as motorized trails or mixed motorized use roads. 

A season of use would be designated on certain routes to provide increased opportunities 

for, and quality of, non-motorized hunting experiences. 

Designation of motorized trails under this alternative is intended to: 1) expand 

opportunities for motorized recreation opportunities, and 2) more accurately describe the 

characteristics and nature of these routes. In other words, these routes do not display 

characteristics associated with roads, such as surfacing, engineering, and prescribed 

clearing widths. They are in many cases very primitive. 

All routes currently exist on the ground and are either currently in the National Forest 

System or are unauthorized (non-system) routes. A total of 505 miles of routes were 

considered by the analysis. A total of 303 miles of routes would be designated for public 

motorized use. Another 141 miles would remain available for administrative use only. 

No cross-country travel areas or construction of new routes is proposed. The proposed 

action does not include winter over-the-snow activity. 

SPECIES ASSESSMENT

Regulatory Framework – Black-footed Ferret 

The black-footed ferret was listed as a federally endangered species under the 

Endangered Species Act (ESA) in March 1967. The recovery plan for the black-footed 

ferret (USFWS 1988) established the national recovery objectives where are to: increase 

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the captive population of ferrets to 200 breeding adults by 1991; establish a prebreeding 

census population of 1,500 free-ranging breeding adults in 10 or more different 

populations with no fewer than 30 breeding adults in each population by the year 2010; 

and encourage the widest possible distribution of reintroduced animals throughout their 

historic range (Federal Register 1996). So far, reintroduction attempts have occurred in 

Wyoming, Montana, South Dakota, Colorado, and Utah. In January 2002, the 

Conservation Plan for Black-tailed and White-tailed Prairie Dogs in Montana was 

approved and implemented in Montana (MTFWP 2002). The overall goal of the plan is 

to “provide for management of prairie dogs populations and habitats to ensure long-term 

viability of prairie dogs and associated species” which included black-footed ferrets 

(MTFWP 2002). In 2002 an annual rule regulating prairie dog shooting on public lands 

was implemented by the State where prairie dogs could not be shot on public lands from 

March 1 thru May 31. The no shooting rule was permanently remanded in 2007 so 

prairie dog shooting on most public land remains open. On January 24, 2008, the U.S. 

Fish and Wildlife Service reintroduced 8 black-footed ferrets on the Northern Cheyenne 

Indian Reservation. The nearest release site was about 80 miles from the Sioux Ranger 

District in Montana and over 100 miles from the closest release site in South Dakota 

(Cheyenne River Indian Reservation). 

Affected Environment – Black-footed ferret 

Black-footed ferrets are intimately tied to prairie dog colonies throughout their range. 

Research from ferret-occupied prairie dog colonies indicates that the most important 

attribute of ferret habitat is the distribution and abundance of prairie dogs. Ferrets are 

therefore limited to the same open habitat used by prairie dogs: grasslands, steppe, and 

shrub steppe (MTNHP 2008). To support a viable population of ferrets, a prairie dog 

colony complex of 2500-3000 ha (6,200-7,400 acres) composed of individual colonies at 

least 12 ha (30 acres) in size, with the majority 50 ha (125 acres) or larger, is needed 

(Forrest et al., 1985, p. 28). Miller et. al. (1996) found that females with young have 

never been found on prairie dog colonies less than 49 ha (121 acres). No black-footed 

ferrets have been documented on the Ranger District since the 1930s. 

Currently there is one known active black-tailed prairie dog (Cynomys ludovicianus) 

colony (< 1 acre) on the Sioux Ranger District. The distribution of prairie dog colonies 

and acreages on adjacent lands is unknown but is thought to be limited based on the 

Conservation Plan for Black-tailed and White-tailed Prairie Dogs in Montana (2002). 

The colony acreage on NFS lands is grossly inadequate to support black-footed ferrets. 

As of August 12, 2004 the USFWS removed the black-tailed prairie dog as a candidate 

for listing under the Endangered Species Act. The black-tailed prairie dog is considered 

as a USFS Northern Region Sensitive species. 

 

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Appendix G: Biological Assessment 

ENVIRONMENTAL CONSEQUENCES – THREATENED AND ENDANGERED 

SPECIES: BLACK-FOOTED FERRET 

Direct and Indirect Effects – Black-footed Ferret 

The presence of roads and trails represents a direct loss of habitat that has already 

occurred, and their use can pose a direct threat of black-footed ferret mortality from 

vehicles. However, black-footed ferrets not know to occur in the area and the project 

area does not support an adequate preybase to support ferrets. Indirectly, the impacts of 

roads include increased access for prairie dog shooters that could have a negative impact 

on prey density. 

Effects Common to All Alternatives. Direct habitat loss would not increase under any 

alternative because construction of new routes is not proposed. None of the alternatives 

analyzed in detail propose increased access to potential black-footed ferret or black-tailed 

prairie dog habitat. All of the alternatives provide the same amount of access to the one 

active prairie dog town 

Vehicle-related black-footed ferret mortality is unlikely given the relatively low speeds 

and traffic volumes on National Forest system roads and the lack of ferrets and adequate 

habitat. 

No vegetation treatment is proposed with this analysis and the components of available 

habitat would not change. 

Alternative A, Alternative B and No Action Alternative. The availability of blackfooted ferret habitat would be effectively the same under Alternatives A, B, and the No 

Action. 

Cumulative Effects – Black-footed Ferret 

Based on the past and current vegetation management on the District, including timber 

harvest, livestock grazing, prescribed fire, the invasive species program, and other 

vegetation projects, grassland/shrub steppe vegetation conditions provide some habitat 

for black-footed ferret and their preferred prey species, black-tailed prairie dogs. The 

impacts of different types of dispersed recreation including the outfitter/guide program; 

hunting; recreational shooting; fire suppression; and the lands, minerals, and nonrecreation special use programs on the District have been minor. Given that anticipated 

direct and indirect effects to lynx and habitats from any of the alternatives is small, 

cumulative effects of past, present, and reasonably foreseeable future activities is also 

expected to be small. 

Consistency with Laws, Regulations, and Policy 

All alternatives are consistent with the laws, regulations, policy, and Federal, Regional, 

the Custer National Forest Management Plan, and State direction in Montana and South 

Dakota, and the Conservation Plan for Black-tailed and White-tailed Prairie dogs in 

Montana (2002). 

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Determination of Effects – Black-footed Ferret 

I have determined implementation of the proposed Federal Action would have NO 

EFFECT ON THE BLACK-FOOTED FERRET OR THEIR HABITAT. My 

determination is based on the following rationale: 1) black-footed ferrets are not know to 

occur in the area; 2) the project area does not support an adequate preybase to support 

ferrets; 3) the amount of occupied black-tailed prairie dog habitat will not grow to an 

adequate level in the near future; 4) direct habitat loss would not increase under any 

alternative because construction of new routes is not proposed; and 5) none of the 

alternatives propose increased access to potential black-footed ferret or black-tailed 

prairie dog habitat. I have also determined implementation of the proposed Federal 

Action MAY IMPACT INDIVIDUALS OR HABITAT BUT IS NOT LIKELY TO 

CAUSE A TREND TO FEDERAL LISTING OR LOSS OF VIABILITY FOR 

BLACK-TAILED PRAIRIE DOGS. My determination is based on the above rationale 

for ferrets along with the fact that prairie dogs will continue to be killed by recreational 

shooting until the States of Montana and South Dakota impose anti-shooting rules. 

Recommendations for Removing, Avoiding, or Compensating Adverse Effects 

None necessary. 

REFERENCES

Federal Register, Volume 61, Number 55, March 20, 1996. 50 CFR Part 17, Endangered 

and Threatened Wildlife and Plants: Establishment of a Nonessential 

Experimental Population of Black-footed Ferrets in Aubrey Valley, Arizona. 

Forrest, S.C., D.E. Biggins, L. Richardson, T.W Clark, T.M. Campbell III, K.A. 

Fagerstone, and E.T. Thorne. 1988. Population attributes for the black-footed 

ferret (Mustela nigripes) at Meeteetse, Wyoming, 1981-1985. J. Mamm. 

69(2):261-273. 

Miller, B., R.P. Reading, and S. Forrest. 1996. Prairie Night. Smithsonian Institute Press. 

Washington D.C. 320 pp. Cited in Montana Field Guide. 

(http://fieldguide.mt.gov/detail_AMAJF02040.aspx) 

MTFWP. 2002. Conservation Plan for Black-tailed and White-tailed Prairie Dogs in 

Montana. Montana Prairie Dog Working Group. 51 pp. 

MTNHP. 2008. Species of Concern Report. Montana Natural Heritage Program 

website. (http://nhp.nris.state.mt.us/SpeciesOfConcern/Default.aspx) 

USFWS. 1988. Black-footed Ferret Recovery Plan. U.S. Fish and Wildlife Service, 

Denver, CO. 154 pp. 

U.S. Fish and Wildlife Service. March 2008. 

http://www.fws.gov/montanafieldoffice/Endangered_Species/Listed_Species.html
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