Endangered and Threatened Wildlife and Plants; 12-Month Finding on a Petition to List Sprague's Pipit as Endangered or Threatened Throughout Its Range, 56028-56050 [2010-22967]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 75, Number 178 (Wednesday, September 15, 2010)]
[Proposed Rules]
[Pages 56028-56050]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2010-22967]



[[Page 56028]]

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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R6-ES-2009-0081]
[MO 92210-0-0008]


Endangered and Threatened Wildlife and Plants; 12-Month Finding 
on a Petition to List Sprague's Pipit as Endangered or Threatened 
Throughout Its Range

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of 12-month petition finding.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a 
12-month finding on a petition to list the Sprague's pipit (Anthus 
spragueii) as endangered or threatened and to designate critical 
habitat under the Endangered Species Act of 1973, as amended (ESA). 
After review of all available scientific and commercial information, we 
find that listing the Sprague's pipit as endangered or threatened is 
warranted. However, listing the Sprague's pipit is currently precluded 
by higher priority actions to amend the Lists of Endangered and 
Threatened Wildlife and Plants. Upon publication of this 12-month 
petition finding, we will add the Sprague's pipit to our candidate 
species list. We will develop a proposed rule to list Sprague's pipit 
as our priorities allow. We will make any determination on critical 
habitat during development of the proposed listing rule. In the interim 
period, we will address the status of the candidate taxon through our 
annual Candidate Notice of Review (CNOR).

DATES: The finding announced in this document was made on September 15, 
2010.

ADDRESSES: This finding is available on the Internet at https://www.regulations.gov at Docket Number FWS-R6-ES-2009-0081. Supporting 
documentation we used in preparing this finding is available for public 
inspection, by appointment, during normal business hours at the U.S. 
Fish and Wildlife Service, North Dakota Field Office, 3425 Miriam 
Avenue, Bismarck, ND 58501. Please submit any new information, 
materials, comments, or questions concerning this finding to the above 
street address.

FOR FURTHER INFORMATION CONTACT: Jeffrey Towner, Field Supervisor, 
North Dakota Field Office (see ADDRESSES); by telephone at 701-250-
4481; by facsimile at 701-355-8513; or by postal mail to: 3425 Miriam 
Ave. Bismarck, ND 58501. If you use a telecommunications device for the 
deaf (TDD), please call the Federal Information Relay Service (FIRS) at 
800-877-8339.

SUPPLEMENTARY INFORMATION:

Background

    Section 4(b)(3)(B) of the ESA (16 U.S.C. 1531 et seq.) requires 
that, for any petition to revise the Federal Lists of Threatened and 
Endangered Wildlife and Plants that contains substantial scientific or 
commercial information that listing a species may be warranted, we make 
a finding within 12 months of the date of receipt of the petition. In 
this finding, we determine whether the petitioned action is: (a) Not 
warranted, (b) warranted, or (c) warranted, but immediate proposal of a 
regulation implementing the petitioned action is precluded by other 
pending proposals to determine whether species are endangered or 
threatened, and expeditious progress is being made to add or remove 
qualified species from the Federal Lists of Endangered and Threatened 
Wildlife and Plants. Section 4(b)(3)(C) of the ESA requires that we 
treat a petition for which the requested action is found to be 
warranted but precluded as though resubmitted on the date of such 
finding, that is, requiring a subsequent finding to be made within 12 
months. We must publish these 12-month findings in the Federal 
Register.

Previous Federal Actions

    On October 10, 2008, we received a petition dated October 9, 2008, 
from WildEarth Guardians, requesting that we list the Sprague's pipit 
as endangered or threatened under the ESA and designate critical 
habitat. Included in the petition was supporting information regarding 
the species' taxonomy and ecology, historical and current distribution, 
present status, and actual and potential causes of decline. We 
acknowledged the receipt of the petition in a letter to WildEarth 
Guardians, dated December 5, 2008. In that letter, we also stated that 
an emergency regulation temporarily listing the species under section 
4(b)(7) of the ESA was not necessary. We also stated that we planned to 
complete the 90-day finding for this species in Fiscal Year (Fiscal 
Year) 2009. On January 28, 2009, we received a 60-day notice of intent 
(NOI) to sue from the petitioner stating that the Service was in 
violation of the ESA by failing to take action under section 4(b)(3)(A) 
of the ESA. On August 20, 2009, the petitioner filed a complaint on the 
Service's failure to complete the 90-day finding.
    We published the 90-day finding in the Federal Register on December 
3, 2009 (74 FR 63337). On May 19, 2010, the Service and WildEarth 
Guardians entered into a settlement agreement. According to the 
agreement, the Service will submit a 12-month finding to the Federal 
Register on or before September 10, 2010. This notice constitutes the 
12-month finding on the October 9, 2008, petition to list the Sprague's 
pipit as endangered or threatened.

Species Information

Taxonomy and Species Description
    The Sprague's pipit is a small passerine of the family 
Motacillidae, genus Anthus, endemic to the Northern Great Plains 
(Robbins and Dale 1999, p. 1). It was first described by Audubon (1844, 
pp. 334-336). It is one of the few bird species endemic to the North 
American prairie. The closest living relative is believed to be the 
yellowish pipit (A. lutescens) of South America (Robbins and Dale 1999, 
p. 9).
    The Sprague's pipit is about 10 to 15 centimeters (cm) (3.9 to 5.9 
inches (in.)) in length, and weighs 22 to 26 grams (g) (0.8 to 0.9 of 
an ounce (oz)), with buff and blackish streaking on the crown, nape, 
and underparts. Males and females are similar in appearance. The 
Sprague's pipit has a plain buffy face with a large eye-ring. The bill 
is relatively short, slender, and straight, with a blackish upper 
mandible. The lower mandible is pale with a blackish tip. The wings and 
tail have two indistinct wing-bars, and the outer retrices (tail 
feathers) are mostly white (Robbins and Dale 1999, p. 3-4). Juveniles 
are slightly smaller, but similar to adults, with black spotting rather 
than streaking (Robbins and Dale 1999, p. 3).
Habitat Description and Characteristics
    Sprague's pipits are strongly tied to native prairie (land which 
has never been plowed) throughout their life cycle (Owens and Myres 
1973, pp. 705, 708; Davis 2004, pp. 1138-1139; Dechant et al. 1998, pp. 
1-2; Dieni et al. 2003, p. 31; McMaster et al. 2005, p. 219). They are 
rarely observed in cropland (Koper et al. 2009, p. 1987; Owens and 
Myres 1973, pp. 697, 707; Igl et al. 2008, pp. 280, 284) or land in the 
Conservation Reserve Program (a program whereby marginal farmland is 
planted primarily with grasses) (Higgins et al. 2002, pp. 46-47). 
Sprague's pipits will use nonnative planted grassland (Higgins et al. 
2002, pp. 46-47; Dechant et al. 1998, p. 3; Dohms 2009, pp. 77-78, 88). 
Vegetation structure may be a better predictor of occurrence than 
species

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composition (Davis 2004, pp. 1135, 1137).
    Native grassland is disturbance dependant. Without disturbance, the 
vegetative species mix changes, and grasslands are ultimately overgrown 
with woody vegetation (Grant et al. 2004, p. 808) unsuitable for 
Sprague's pipits. Historical sources of disturbance were fire or 
grazing by bison. With fires being less prevalent on the prairie, 
current sources of disturbance are generally mowing or grazing by 
cattle. While Sprague's pipits prefer areas that are regularly 
disturbed (Askins et al. 2007, p. 21; Madden 1996, pp. 48-59), their 
preference for vegetation of intermediate height means that they will 
not use a mowed or burned area until the vegetation has had a chance to 
grow, which may be late in the following growing season, or may take 
several seasons (Dechant et al. 1998, pp. 1-2; Kantrud 1981, p. 414). 
The frequency of disturbance required for habitat maintenance depends 
on how quickly the grasses grow following a disturbance event, with 
precipitation rates being a major driver. For example, pre-colonial 
fire return rates are estimated to be approximately 6 years in North 
Dakota, but 10 to 26 years in Montana and other relatively dry portions 
of the range (Askins et al. 2007, pp. 20-21). After bison grazed an 
area, they may not have returned for 1 to 8 years (Askins et al. 2007, 
p. 21).
Breeding Range and Habitat
    The breeding range is described as throughout North Dakota, except 
for the easternmost counties; northern and central Montana east of the 
Rocky Mountains; northern portions of South Dakota; and northwestern 
Minnesota. In Canada, Sprague's pipits breed in southeastern Alberta, 
the southern half of Saskatchewan, and in southwest Manitoba (Robbins 
and Dale 1999, p. 5).
    During the breeding season, Sprague's pipits prefer large patches 
of native grassland with a minimum size requirement thought to be 
approximately 145 ha (358.3 ac) (range 69 to 314 ha (170 to 776 ac)) 
(Davis 2004, p. 1134). They were not observed in areas smaller than 29 
ha (71.6 acres) (Davis 2004, p. 1134). While they have been reported to 
be less abundant in or absent from grassland that has been planted 
(Madden 1996, p. 104), recent research suggests that nesting success in 
planted grassland is similar to nesting success in native habitat 
(Dohms 2009, pp. 41-81). Preferred grass height has varied between 
studies, but is estimated to be between 10 and 30 cm (4 and 12 in.) 
(Dieni and Jones 2003, p. 390; Madden et al. 2000, p. 382; Sutter 1997, 
pp. 464-466). They will use nonnative planted grassland if the 
vegetative structure is suitable, but strongly prefer native prairie 
(Dechant et al. 1998, pp. 1, 4). The species prefers to breed in well-
drained, open grasslands and avoids grasslands with excessive shrubs 
(Desmond et al. 2005, p. 442; Grant et al. 2004, p. 812; Sutter 1997, 
p. 464).
    Sprague's pipits can be found in lightly to moderately grazed areas 
(Dechant et al. 1998, p. 4), but in North Dakota, a greater abundance 
of Sprague's pipits have been reported from moderately to heavily 
grazed areas (Kantrud 1981, p. 414). However, these descriptions are 
relative; vegetation described as lightly grazed in one study may be 
called heavily grazed in another (Madden et al. 2000, p. 388). The 
species is rarely found in cultivated areas (Owens and Myres 1973, p. 
705). They may avoid roads, trails, and habitat edges (Dale et al. 
2009, pp. 194, 200; Koper et al. 2009, pp. 1293-1295; Linnen 2008, p. 
1; Sutter et al. 2000, p. 114).
Migration and Wintering Range and Habitat
    The Sprague's pipit's wintering range includes south-central and 
southeast Arizona, Texas, southern Oklahoma, southern Arkansas, 
northwest Mississippi, southern Louisiana, and northern Mexico. There 
have been migration sightings in Michigan, western Ontario, Ohio, 
Massachusetts, and Gulf and Atlantic States from Mississippi east and 
north to South Carolina. Sprague's pipits also have been sighted in 
California during fall migration (Robbins and Dale 1999, p. 6).
    Migration and wintering ecology are poorly known, but migrating and 
wintering Sprague's pipits are found in both densely and sparsely 
vegetated grassland, and pastures (Desmond et al. 2005, p. 442; Emlen 
1972, p. 324). They are rarely found in fallow cropland (Wells 2007, p. 
297). Sprague's pipits exhibit a strong preference for grassland 
habitat during the winter and an avoidance of areas with too much shrub 
encroachment (Desmond et al. 2005, p. 442). Their use of an area is 
dependent on habitat conditions. On their wintering grounds, after a 
wet year, when grass is denser, Sprague's pipits were dense, compared 
with few individuals in the same areas after dry years when grasses 
were sparse (Dieni et al. 2003, p. 31; Maci[acute]as-Duarte et al. 
2009, p. 869). They are not found in the narrow strips of grassland 
remaining along agricultural field borders (Desmond et al. 2005, p. 
448). In migration, they may be found near or on trails and roads or 
near water (Maher 1973, p. 20), and they have been sighted in sunflower 
fields (Hagy et al. 2007, p. 66).
    It has been estimated that only about 2.5 percent of the entire 
Chihuahuan desert region, an ecosystem extending across the border 
between the United States and Mexico entirely within the wintering 
range of the Sprague's pipit, is protected, mostly on the U.S. side 
(Desmond et al. 2005, p. 449).
Feeding Habits
    Sprague's pipits eat a wide variety of insects during the breeding 
season and a very small percentage of seeds (1 to 2 percent) (Maher 
1974, pp. 5, 32, 58).
Breeding Phenology
    Male Sprague's pipits have a territorial flight display that takes 
place high in the air and that can last up to 3 hours (Robbins 1998, 
pp. 435-436). Sprague's pipits are very secretive around the nest 
itself, sometimes not flushing until a searcher is extremely close 
(Jones and Dieni 2007, p. 123). When returning to the nest, they can 
land several meters away and run to the nest through the grass (Jones 
and Dieni 2007, p. 123).
    Nests are generally constructed in areas of relatively dense cover, 
low forb density, and little bare ground (Sutter 1997, p. 462). The 
nest is usually dome-shaped; is constructed from woven grasses; and is 
generally at the end of a covered, sharply curved runway up to 15 cm 
(5.9 in.) long which may serve as heat-stress protection (Sutter 1997, 
p. 467; Dechant et al. 1998, p. 2). The female lays four to five eggs 
(Allen 1951, p. 379; Maher 1973, p. 25), which she incubates for 11 to 
17 days (Davis 2009, pp. 265, 267). Females may do most or all of the 
incubation (Sutter et al. 1996, p. 695), but both parents may feed the 
young (Dohms and Davis 2009, p. 826). Parental care likely continues 
well past fledging (Harris 1933, p. 92; Sutter et al. 1996, p. 695). 
The female will renest if the first nest fails, and some females have 
been documented successfully nesting two times during one breeding 
season (Sutter et al. 1996, p. 694; Davis 2009, p. 265). Long intervals 
between renesting attempts suggest that the rate of renesting is low 
(Sutter et al. 1996, p. 694). However, breeding pairs may only produce 
an average of 1.5 clutches per year (Sutter et al. 1996, p. 694). Males 
were documented to be polygamous (have two females on two nests at the 
same time), but the rate of polygyny is unknown (Dohms and Davis 2009, 
pp. 826, 828).

[[Page 56030]]

Population Trend Information
    Due to its cryptic coloring and secretive nature, the Sprague's 
pipit has been described as ``one of the least known birds in North 
America'' (Robbins and Dale 1999, p. 1), and range-wide surveys for the 
species have not been conducted. The population from 1990-1999 was 
estimated at approximately 870,000, based on extrapolation of Breeding 
Bird Survey (BBS) data (Blancher et al. 2007, p. 27; Rich et al. 2004, 
p. 18). The population has continued to decline since that time (Sauer 
et al. 2008, p. 13). The species was described as abundant in the late 
1800s in the upper Missouri River basin (Coues 1874, p. 42; Seton 1890, 
p. 626). More recent long-term estimates of Sprague's pipit abundance 
are derived from the BBS, a long-term, large-scale survey of North 
American birds that began in 1966. The BBS is generally conducted by 
observers driving on roads along established routes, with stops every 
half-mile to sample for birds. Because Sprague's pipits avoid roads 
(Sutter et al. 2000, p. 114), roadside surveys may not be the best 
measure of abundance of Sprague's pipits (Sutter et al. 2000, pp. 113-
114). Nonetheless, the methods of the BBS have been consistent through 
time, and are the best available information for the breeding range at 
this time. The trend analysis suggests that the population is in steep 
decline (Peterjohn and Sauer 1999, p. 32), with an estimated 80-percent 
decrease from 1966 through 2007 in the U.S. and Canadian breeding range 
(approximately 3.9 percent annually) (Sauer et al. 2008, p. 8). The 
annual population decline shows some slight variation, but the long-
term trend is consistently negative (95-percent confidence interval -
5.6 to -2.2) (Sauer et al. 2008, pp. 5-6, 8). Assuming that the 
population was approximately 870,000 in 1995 (the mid-point between 
1990 and 1999 (Rich et al. 2004, p. 18)), and the population continues 
to decline at 3.9 percent annually, the population would have declined 
to approximately 479,000 by 2010. By 2060, the population could drop to 
66,000, and in 100 years, by 2110, the population could decline to 
8,970. However, this estimate involves a number of assumptions. The 
original population estimate comes from the BBS data and is 
characterized as ``beige,'' indicating that the 95-percent confidence 
limit around the average is within 20 percent of the average itself 
(Blancher et al. 2007, p. 22). Additionally, this assumes that the 
population will continue to decline in a linear fashion.
    In addition to BBS surveys, the Canadian Wildlife Service conducts 
a Grassland Bird Monitoring program (GBM) using the same methodology as 
the BBS. GBM surveys are conducted along roads in areas within the 
mixed-grass prairie ecosystem where grassland is still common (Dale et 
al. 2005, entire; Environment Canada 2008, pp. 3-4). The GBM survey 
shows an even sharper decline of 10.5 percent annually from 1996-2004 
in the core area of Sprague's pipit's habitat in Canada (Environment 
Canada 2008, pp. iii, 3-4). The GBM program decline compares with a 
1.8-percent decline for the same period from the BBS data (Environment 
Canada 2008, pp. iii, 3-4). Since the GBM survey is conducted in 
habitat that should be optimal for Sprague's pipits in Canada, it 
indicates a serious decline in species abundance (Environment Canada 
2008, p. 4).
    The Christmas Bird Count (CBC) represents the only long-term data 
set that we are aware of that includes wintering information for the 
Sprague's pipit. The CBC is an annual count performed around the end of 
December in which volunteers observe birds in 15-mile-radius ``count 
circles.'' The Sprague's pipit CBC data from the winters of 1966/1967 
through 2005/2006 (a 40-year span) were analyzed following the methods 
described in Link et al. (2006, entire) (Niven 2010, pers. comm.). The 
40-year trend data for Sprague's pipit shows an annual decline for 
Texas (2.54 percent), Louisiana (6.21 percent), Mississippi (10.21 
percent), and Arkansas (9.27 percent). The data from Oklahoma, New 
Mexico, Arizona, Florida, and California indicated an uncertain or 
stable trend (Niven 2010, pers. comm.). California and Florida are 
outside of the described range, and the number of sightings was quite 
low, presumably representing a few birds straying off of their normal 
migration routes or wintering areas. Oklahoma is part of the migration 
route, so sightings there in December may be somewhat varied, depending 
on annual weather conditions. Overall, the 40-year trend showed a 
median declining population of approximately 3.23 percent annually and 
a 73.1-percent decline for the entire time period (Niven 2010, pers. 
comm.). These estimates are fairly consistent with the decline observed 
on the breeding grounds, indicating that the observed decline is real, 
rather than an artifact of the sampling technique.
    Sprague's pipit is included on a number of Federal, State, and 
nongovernmental organization lists as a sensitive species. Sprague's 
pipit is listed in the Birds of Conservation Concern, a list of bird 
species (beyond those already federally listed as threatened or 
endangered) in greatest need of conservation action. The list is 
derived from three bird conservation plans: the Partners in Flight 
North American Landbird Conservation Plan, the United States Shorebird 
Conservation Plan, and the North American Waterbird Conservation Plan 
(Service 2008, pp. iii, 1, 27, 28-34, 35, 37, 41 50- 53, 58, 60, 63, 
67, 76, 85). Sprague's pipits' status is listed as vulnerable on the 
International Union of Conservation Networks Red List (Birdlife 
International 2008, p. 1). It has a NatureServe Global Rank of G4, 
indicating that the population is apparently secure (NatureServe 2009, 
p. 1). The species is ranked as yellow on the Audubon 2007 watch list, 
indicating that it is either declining or rare. Species on the Audubon 
watch list typically are species of national conservation concern 
(Audubon 2007, p. 2). Partners in Flight also has placed Sprague's 
pipit on its watch list, indicating that the species is a species of 
conservation concern at the global scale, a species in need of 
management action, and a high priority candidate for rapid status 
assessment (Rich et al. 2004, p. 18).
    Several states have identified the Sprague's pipit as a sensitive 
species in their State wildlife action plans, including Arizona, 
Louisiana, Minnesota, Montana, New Mexico, North Dakota, South Dakota, 
and Texas (Arizona Game and Fish Department 2010, p. 3; Louisiana 
Department of Wildlife and Fisheries 2005, p. 6; Minnesota Department 
of Natural Resources 2010, p. 1; Montana Fish, Wildlife and Parks 2010, 
p. 2; New Mexico Game and Fish 2010, p. 4; North Dakota Game and Fish 
Department 2010, p. 3; South Dakota Game, Fish, and Parks 2010, p. 3; 
Texas Parks and Wildlife 2005, p. 6). The criteria used to determine 
which species are listed as species of greatest conservation concern 
varies by State, but generally include known information about 
population trends on a State, regional, and national level; the 
importance of the State in the species' range; and often rankings on 
national lists (for example Natureserve and the Audubon watch list 
(NatureServe 2009, p. 1; Audubon 2007, p. 2)).

Summary of Information Pertaining to the Five Factors

    Section 4 of the ESA (16 U.S.C. 1533) and implementing regulations 
(50 CFR 424) set forth procedures for adding species to the Federal 
Lists of Endangered and Threatened Wildlife and Plants. Under section 
4(a)(1) of the ESA, a species may be determined to be

[[Page 56031]]

endangered or threatened based on any of the following five factors:
    (A) The present or threatened destruction, modification, or 
curtailment of its habitat or range;
    (B) Overutilization for commercial, recreational, scientific, or 
educational purposes;
    (C) Disease or predation;
    (D) The inadequacy of existing regulatory mechanisms; or
    (E) Other natural or manmade factors affecting its continued 
existence.
    In considering what factors might constitute threats, we must look 
beyond the exposure of the species to the factor to determine whether 
the species responds to the factor in a way that causes actual impacts 
to the species. If there is exposure and the species responds 
negatively, the factor may be a threat and we then attempt to determine 
how significant a threat it is. If the threat is significant, it may 
drive or contribute to the risk of extinction of the species such that 
the species warrants listing as endangered or threatened as those terms 
are defined by the ESA.

Factor A. Present or Threatened Destruction, Modification, or 
Curtailment of the Habitat or Range.

Habitat Conversion
    Thirty percent of prairie habitat in the Great Plains and Canada 
remains from pre-colonial times (Samson et al. 2004, p. 7), but as 
discussed below, the amount of suitable habitat remaining in the 
Sprague's pipit's range is much lower. Land conversion is accelerating 
in native prairie, with a conversion rate faster than the estimated 
conversion rate of rainforests in the Amazon (Stephens et al. 2008, pp. 
1326-1327). Much of the land conversion is from native prairie to 
agricultural uses.. A Government Accountability Office report on 
agricultural conversion documented the continued conversion of native 
prairie to cropland, particularly in the Northern Plains of Montana, 
North Dakota, and South Dakota (Government Accountability Office 2007, 
pp. 4, 12, 15). A number of factors that encourage farmers to convert 
native prairie were identified, including; higher crop prices, 
especially for corn; farm payment programs that increase expected 
cropland profitability without increasing risk; the advent of 
herbicide-ready crops, and no-till farming methods, which allow farmers 
to plant directly into native prairie. The Northern Plains is 
identified as an area with continued conversion of native grassland 
(Government Accountability Office 2007, p. 4). From 2005 through 2007 
(the most recent year data was available), approximately 94,400 ha 
(233,000 acres) of virgin prairie was broken for the first time, or 
approximately 32,000 ha (78,000 acres) annually (Stephens 2010, pers. 
comm.).
    To determine the amount of potentially suitable habitat remaining 
within the Sprague's pipit's range, we performed a Geographic 
Information System (GIS) analysis for the U.S. portion of the breeding 
range (Loesch 2010, pers. comm.). We based the breeding range on data 
from the BBS in the U.S. range, and included cover types which were 
classified as grassland, pastureland, prairie, or temporary wetland 
(Loesch 2010, pers. comm.). From these data, we determined that 
approximately 2.1 percent of the total area (10 million ha [25 million 
ac]) in the Sprague's pipit's U.S. breeding range as defined by the BBS 
remains in suitable habitat, with most of the historic range converted 
to other uses. Nonsuitable land cover types within the Sprague's 
pipit's range include urban areas, transportation infrastructure, 
barren areas, cropland, forest, tree rows, shrublands, water, and 
wetland areas. Researchers predict that native grassland will continue 
to be converted, and the rate of conversion may increase (Fargione et 
al. 2009, p. 769; Stephens et al. 2008 p. 1328). Prairie habitat loss 
in the Missouri River Coteau is estimated to be approximately 0.4 
percent annually (Stephens et al. 2008, pp. 1320, 1327). Even in areas 
that remain in native prairie, historic and current land management, 
including increased stocking levels, fencing, augmentation of water 
sources (which concentrate animals, making overgrazing more likely), 
and fire suppression, have all changed the grassland ecology and 
species mix (Knopf 1994, pp. 248-250; Weltzin et al. 1997, pp. 758-
760). The changes in the grassland ecosystem have led to a steep 
decline in many grassland bird species, including the Sprague's pipit 
(Knopf 1994, pp. 251-254; Grant et al. 2004, p. 812; Lueders et al. 
2006, pp. 602-604).
    As in the United States, most of the native grasslands in Canada 
have been converted to other uses, which are largely not suitable for 
nesting of the Sprague's pipit (Environment Canada 2008, p. 6). 
Analysis done with imagery taken around 2000 suggested that 
approximately 94 percent of the species' range has been lost in Canada 
(Dale 2010, pers. comm.). Of the approximately 20 million ha (49.4 
million ac) remaining as grassland in the Sprague's pipit's range in 
Canada, 15 to 20 percent (3 to 4 million ha (7.4 to 9.9 million ac)) 
remains in patches large enough to support breeding territories (Dale 
2010, pers. comm.).
    Prairie conversion is continuing, and is expected to continue 
(Fargione et al. 2009, p. 775; Stephens et al. 2008, pp. 1320, 1325). 
Because of the decreased amount of suitable native prairie remaining 
throughout the United States and Canada, the continued conversion of 
native prairie to other land uses, and the altered management regime in 
the native prairie that remains, we conclude that ongoing habitat loss 
and land conversion is a significant threat (i.e., a threat that, alone 
or in combination with other factors, is causing the species to be in 
danger of extinction, now or in the foreseeable future) to Sprague's 
pipit throughout its range.
Grazing
    Grazing is a major driver in the prairie ecosystem. An appropriate 
level of grazing can help to maintain the prairie habitat, while too 
much or too little may make the habitat unsuitable for Sprague's 
pipits. Much of the prairie is now grazed more uniformly than it was in 
pre-colonial times and is often overgrazed, leading to a decline in 
species diversity and an increase in woody structure (since cattle do 
not eat woody vegetation, it has a competitive advantage over grass if 
some other mechanism is not used to remove trees and shrubs) (Walker et 
al. 1981, pp. 478-481; Towne et al. 2005, pp. 1550-1558). Additionally, 
cattle have replaced bison as the primary herbivore in Sprague's pipit 
habitat. Substituting cattle for bison does not necessarily lead to a 
change in grassland vegetation. A study comparing native prairie 
stocked with moderate levels of cattle to native prairie stocked with 
moderate levels of bison determined that, while there were some 
differences in the grazing habits of the two species, after 10 years 
the plant diversity and plant density in the two areas were similar 
(Towne et al. 2005, pp. 1552-1558). The authors suggest that the 
vegetation differences that many studies find between native prairie 
grazed by cattle and native prairie grazed by bison are due to 
different herd management practices and grazing intensity, rather than 
an inherent difference in the effect of the two herbivore species on 
vegetation (Towne et al. 2005, p. 1558). Ranchers often allow cattle to 
graze at high densities compared to the historic grazing densities of 
bison, which leads to a greater probability of overgrazing in 
grasslands (Towne et al. 2005, p. 1558). However, one study (Lueders et 
al. 2006, p. 602) noted that Sprague's pipits were more common on areas 
grazed by cattle than areas grazed by bison. The

[[Page 56032]]

management regimes (i.e., fire regimes, grazing densities) and sampling 
intensities of studies conducted on the two areas were quite disparate, 
precluding firm conclusions.
    While improperly timed or overly heavy or light grazing negatively 
impacts Sprague's pipits' ability to use an area, we do not believe 
that grazing is a major threat to Sprague's pipits. While some areas 
are undoubtedly poorly managed, we believe this is a local rather than 
a rangewide problem. There is not enough information at this time to 
determine conclusively how grazing or substituting cattle for bison 
throughout much of the range impacts the Sprague's pipit, but from the 
available information, we do not believe that grazing is a significant 
threat to the species.
Fire
    Like grazing, fire is a major driver on the prairie ecosystem. 
While there are still some controlled and wild prairie burns, fire is 
no longer a widespread regular phenomenon as it was in pre-colonial 
times. Fire suppression has allowed suites of plants, especially woody 
species, to flourish (Knopf 1994, p. 251; Samson et al. 1998, p. 11). 
Fire suppression since European settlement throughout the Sprague's 
pipit's range has impacted the composition and structure of native 
prairie, favoring the incursion of trees and shrubs in areas that were 
previously grassland (Knopf 1994, p. 251). This change of structure 
negatively impacts Sprague's pipits, which avoid trees and are 
negatively associated with shrub cover on both their breeding and 
wintering grounds (Desmond et al. 2005, p. 442; Grant et al. 2004; p. 
812; Sutter 1997, p. 464). Eliminating fire from the landscape has 
likely changed the overall composition of the prairie (Towne et al. 
2005, pp. 1557-1558). Trees and shrubs can be controlled to some extent 
through grazing or eliminated by regular mowing, although these 
management practices may result in selection for yet another suite of 
grassland plant species (Owens and Myres 1973, pp. 700-701).
    The lack of widespread fire in current prairie management has 
contributed to land conversion to landcover types not suitable for the 
pipit. Some form of disturbance is necessary to maintain the grassland 
ecosystem, and grazing and mowing are generally used today. While the 
lack of widespread fires as a management technique has led to changes 
in the grassland ecosystem, we believe that other methods of habitat 
maintenance are substituting for the role that fire historically 
played, albeit while selecting for a different suite of grassland 
species. We do not have information to suggest that the change in fire 
regime is a significant threat to the species.
Mowing
    Like grazing and fire, mowing is a management technique that can be 
used as a source of disturbance to prevent woody species from invading 
into grassland habitat. However, mowing (i.e., haying) in the breeding 
range could negatively impact Sprague's pipits by directly destroying 
nests, eggs, nestlings, and young fledglings, and by reducing the 
amount of nesting habitat available in the short term. Nest success of 
ground-nesting birds is already low, with an estimated 70 percent of 
nests destroyed by predators (Davis 2003, p. 119). While Sprague's 
pipits occasionally will renest if the first nest fails or if nestlings 
from the first clutch fledge early enough in the season, long intervals 
between nesting attempts suggest that renesting is relatively uncommon 
(Sutter et al. 1996, p. 694). Thus, early mowing can negatively impact 
reproductive success for the year. Even mowing done later in the season 
after chicks have fledged may impact the availability of breeding 
habitat the following year because Sprague's pipits will not use areas 
with short grass until later in the season when the grass has grown, 
possibly due to dense revegetation and the lack of litter (Dechant et 
al. 1998, p. 3; Owens and Myres 1973, p. 708; Kantrud 1981, p. 414). On 
the other hand, as noted above, mowing can improve Sprague's pipit 
habitat in the long term by removing trees and shrubs (Owens and Myres 
1973, p. 700).
    There is not sufficient information available about the extent, 
timing, and frequency of mowing throughout the species' range to make 
firm conclusions about how much of a threat mowing poses. Since mowing 
can play both a positive and negative role in the maintenance of 
Sprague's pipit habitat, the impacts of mowing are mixed. In some parts 
of the range where large portions of the remaining grasslands are mowed 
annually or grass growth is slow or both, mowing may be negatively 
impacting the population. However, at this time, we do not have 
information to indicate that mowing is a significant threat to the 
species rangewide.
Habitat Fragmentation on the Breeding Grounds
    Whereas direct conversion of native prairie results in an obvious 
loss of habitat, fragmentation of the remaining native prairie can make 
large portions of otherwise suitable habitat unusable for nesting 
Sprague's pipits. A number of studies have found that Sprague's pipits 
appear to avoid non-grassland features in the landscape, including 
roads, trails, oil wells, croplands, woody vegetation, and wetlands 
(Dale et al. 2009, pp. 194, 200; Koper et al. 2009, pp. 1287, 1293, 
1294, 1296; Greer 2009, p. 65; Linnen 2008, pp. 1, 9-11, 15; Sutter et 
al. 2000, pp. 112-114). The extent to which Sprague's pipits avoids 
roads varies between studies. One study found that of 46 mapped 
Sprague's pipit territories, only 5 (11 percent) crossed a trail or 
pipeline (in Dale et al. 2009, p. 200). However, other studies found 
that Sprague's pipits avoid roads but not trails, presumably because of 
the difference in structure in the road right-of-way (Sutter et al. 
2000, p. 110), and one study did not document avoidance of roads, 
although it did document avoidance of other changes in habitat 
structure (Koper et al. 2009, pp. 1287, 1293). Sprague's pipits may be 
particularly sensitive to habitat fragmentation because their high 
flight display affords them a wide view of the area, and thus they may 
select their territories based on landscape, rather than site-specific 
features (Koper et al. 2009, p. 1298).
    The effect of a non-grassland feature (e.g., shrubs, trees, roads, 
human-made structures) in the landscape can be much larger than its 
actual footprint. Sprague's pipits are sensitive to patch size (i.e., 
the amount of contiguous native grassland available (Davis 2004, pp. 
1134, 1135-1137; Davis et al. 2006, pp. 812-814; Greer 2009, p. 65)), 
and they avoid edges between grassland and other habitat features that 
are structurally different than grassland (Davis 2004, p. 1134; Koper 
et al. 2009, pp. 1287, 1293-1296). Sprague's pipits were not found in 
patches less than 29 ha (71.7 ac), and the minimum size requirement is 
thought to be 145 ha (358.3 ac) (range 69 to 314 ha (170 to 776 ac)) 
(Davis 2004, p. 1134), with even larger patches preferred (Davis 2004, 
pp. 1134-1135, 1138; Greer 2009, p. 65).
    The shape of the patch also is important. Since Sprague's pipits 
have been shown to avoid edges (Linnen 2008, pp. 1, 9-11, 15), 
grassland areas with a low edge-to-area ratio provide optimal habitat 
(Davis 2004, pp. 1139-1140). Thus, a linear patch may not be suitable 
for a Sprague's pipit's territory, even if it is sufficiently large. 
Koper et al. (2009, p. 1295) noted that conversion of one quarter 
section (64 ha (158 ac)) in the middle of a grassland patch reduced the 
utility of an additional 612 ha (1,512 ac) of grassland.
    Because of the Sprague's pipit's selection for relatively large 
grassland

[[Page 56033]]

areas and avoidance of edges, habitat fragmentation is a threat 
throughout the population's breeding range. As more roads, oil and gas 
development, wind farms, and other features are constructed in the 
Northern Great Plains, the fragmentation of the native prairie is 
expected to increase, further decreasing the amount of suitable habitat 
in large enough patches to be used by breeding pairs.
    In order to determine the potential cumulative impact of human 
features on Sprague's pipits, we performed a GIS analysis. We used the 
BBS to map the breeding distribution of the species. The BBS uses 
inverse distancing to smooth the data by using route relative abundance 
to estimate presence beyond the end of a survey road (Sauer et al. 
2008, pp. 17-19). We overlaid layers of suitable Sprague's pipit 
habitat, the road system, permitted oil and gas wells, and existing 
wind towers in the U.S. breeding range. Since GIS information regarding 
the location of the roads constructed by the energy companies to access 
their wells or towers was not available, we estimated new road 
construction by having the GIS program measure the shortest distance 
from the nearest road to the energy feature (Loesch 2010, pers. comm.). 
Topography may preclude building a road following the most direct 
route, so this is a conservative estimate of the miles of new roads 
constructed. We buffered the roads, wind towers, and oil and gas well 
pads by 350 m (1148 ft) based on an estimate of Sprague's pipits' 
avoidance of oil pads and associated roads (Linnen 2008, pp. 1, 9-11).
    As noted above, approximately 2 percent of the U.S. breeding range 
remains in a habitat type that is potentially suitable for Sprague's 
pipit nesting. When we overlaid current and approximated roads, oil and 
gas wells, and wind development, the amount of suitable habitat in 
patches larger than 145 ha (358.3 ac), described as the minimum size 
requirement for breeding Sprague's pipits (Davis 2004, p. 1134), 
declined to 1.55 percent of the historic breeding range (Figure 1) 
(Loesch 2010, pers. comm.). If we include habitat patches 29 ha (71.6 
ac) or larger, the smallest patch size where Sprague's pipits were 
observed (Davis 2004, p. 1134), the amount of potentially suitable 
habitat increases marginally to 1.86 percent of the historic breeding 
range in the United States (Loesch 2010, pers. comm.). If energy 
development continues as projected, the amount of suitable habitat will 
decline even further.
    FIGURE 1: Current grassland habitat patches for Sprague's pipits of 
145 ha (358.3 ac) or larger in areas of the north-central United States 
where the species has been encountered by the BBS (Loesch 2010, pers. 
comm.).

[[Page 56034]]

[GRAPHIC] [TIFF OMITTED] TP15SE10.019

    A similar GIS analysis of remaining suitable breeding habitat in 
Canada, including oil and gas wells, roads, and trails leading to each 
well, determined that about 5.6 percent of the Canadian range is 
suitable (having a greater than 50 percent probability of occupancy) 
for Sprague's pipits (Dale 2010, pers. comm.). A similar estimate (5 to 
6 percent) was independently reached by another researcher also 
analyzing land cover data for the Canadian range (Davis 2010, pers. 
comm.).
    Our analysis shows that the remaining suitable habitat continues to 
be converted and fragmented, a trend that we expect to increase. With 
only 1.55 to 1.86 percent of the U.S. historic breeding habitat and 
only approximately 15 to 20 percent of the Canadian breeding habitat 
still suitable for Sprague's pipit nesting, the areas where birds can 
relocate to as more habitat becomes fragmented and unsuitable for 
Sprague's pipit nesting is drastically diminished. As development 
continues, we expect the potential area for Sprague's pipits to nest to 
decline further. The existing and ongoing fragmentation of suitable 
habitat makes the long-term observed decline of Sprague's pipit likely 
to continue into the future.
Energy Development
    Energy development (oil, gas, and wind) and associated roads and 
facilities increase the fragmentation of grassland habitat. Much of the 
Sprague's pipit's breeding range overlaps with major areas of oil and 
gas development, which have been increasing rapidly in some portions of 
the Sprague's pipit's range. In North Dakota, the number of drilling 
permits nearly doubled between 2007 and 2008, from 494 permits issued 
in 2007 to 946 in 2008 (North Dakota Petroleum Council 2009, p. 2). 
This trend is expected to increase; up to 1,850 wells could be drilled 
annually for a total of up to 19,860 additional wells in North Dakota 
over the next 20 years (North Dakota Department of Mineral Resources 
Undated, pp. 7-17). Oil officials anticipate that production will 
continue to expand at record levels (MacPherson 2010; entire). Much of 
the oil activity is occurring in areas of native prairie, a trend that 
we expect to continue (Loesch 2010, pers. comm). The Bakken formation 
that is currently being drilled lies entirely within the U.S. and 
Canadian breeding range (USGS 2008, p. 1; Robbins and Dale 1999, p. 5). 
Sprague's pipits avoid oil wells, staying up to 350 meters (m) (1148 
feet (ft)) away (Linnen 2008, pp. 1, 9-11), magnifying the effect of 
the well feature itself. Oil and gas wells, especially at high 
densities, decrease the amount of habitat available for breeding 
territories. We calculated that each well and associated road has 
impacted approximately 21 ha (51 acres), including the area that 
Sprague's pipits avoid (Loesch 2010, pers. comm.). Thus, an additional 
19,860 wells could impact 400,000 ha (1 million acres) just in the 
Sprague's pipit range in North Dakota.
    Each oil and gas well pad requires some amount of associated new 
road construction. As discussed above, there is evidence that Sprague's 
pipits avoid roads and trails on the breeding grounds (Linnen 2008, pp. 
1, 9-11; Dale et al. 2009, p. 200). Oil and gas development has been 
shown to double the density of roads on range lands (Naugle et al. 
2009, pp. 11, 46). In areas with ranching, tillage agriculture, and oil 
and gas development, 70 percent of the land was within 100 m (109 yards 
(yd)), and 85 percent of the land was within 200 m (218 yd), of a human 
feature (Naugle et al. 2009, p. 11). Researchers estimated that in 
those areas, every square km (0.39 square miles) of land may be both 
bounded by a road and bisected by a powerline (Naugle et al. 2009, p. 
11). With increased oil and gas development in much of the Sprague's 
pipit's range, this level of fragmentation is likely to be occurring 
over a large percentage of the range. As discussed above, habitat

[[Page 56035]]

fragmentation is one of the major threats facing the species.
    Wind energy development has been increasing rapidly in recent 
years, with increases of more than 45 percent in 2007, and more than 50 
percent in 2008 (Manville 2009, p. 1). Like oil development, wind 
projects built in native grassland fragment the habitat with turbines, 
towers, roads, transmission infrastructure, and associated facilities. 
We estimate that each turbine and associated road impacts approximately 
34.5 ha (85.3 acres) of land, including an area around the road that 
Sprague's pipits avoid (Linnen 2008, p. 9-10; Loesch 2010, pers. 
comm.). However, because most turbines are placed close enough together 
for the avoidance areas to overlap, we calculated the impact of each 
individual turbine to be less, approximately 16.4 ha (40.5 acres) per 
turbine on average. To date, we estimate that 12,400 ha (30,522 ac) 
have been impacted by 752 wind turbines and associated roads within the 
Sprague's pipit U.S. range. We anticipate the number of wind farms to 
continue to increase dramatically throughout the species' range. For 
example, in North Dakota alone, we are aware of a plan to construct 
4,194 new turbines within the Sprague's pipit's range (Ellsworth 2010, 
pers. comm.). This proposed development has the potential to make 
69,200 to 145,000 ha (170,000 to 358,000 acres) of land unsuitable for 
pipit nesting, depending on how the turbines are spaced. This likely 
represents a fraction of potential habitat loss from wind energy 
development, because we typically are not informed of wind projects 
until sites are selected.
    North Dakota and South Dakota each have the potential wind-energy 
capacity of at least 4 mega-watts (MW) of wind power per km\2\, while 
Montana has been projected to have the potential for 3 to 4 MW of wind 
power per km\2\ (National Research Council 2007, p. 45). We calculated 
how much of the Sprague's pipit's U.S. range this amount of development 
may impact, using the following assumptions:
    1) Each turbine would provide 2 MW of power. Onshore turbines are 
constructed between 700 kW to 2.5 MW (American Wind Energy Association 
2010, p. 3), with most industrial projects that we are aware of in the 
1.5 MW range. However, wind industry is working toward developing 
larger turbines , so we believe that in the future turbine size is 
likely to be 2 MW or greater.
    2) Future wind projects would be constructed at approximately the 
same density as existing wind farms in these states, with the area of 
habitat that Sprague's pipits avoid from one turbine overlapping the 
avoidance area from another. We also assume that each turbine, road and 
associated area makes approximately 16.4 ha (40.5 acres) of habitat 
unsuitable for nesting.
    3) Turbines would be evenly distributed across the Sprague's pipit 
range in the U.S. This assumption is likely conservative in terms of 
effects to habitat because the areas with the highest wind potential in 
these states are largely within the remaining suitable prairie habitat. 
Major wind development is likely to occur in the remaining suitable 
Sprague's pipit habitat (U.S. Department of Energy 2010a, p. 1; Loesch, 
pers. comm. 2010).
    Using the above assumptions, we estimate that a minimum of 4.8 
million hectares (12 million acres) could become unsuitable for nesting 
within the range in North Dakota and a minimum of 2.1 million ha (5.1 
million acres) could become unsuitable in South Dakota, while in 
Montana from 6.6 to 8.8 million hectares (16.4 to 21.8 million acres) 
could be impacted. While full development of the wind potential in 
Sprague's pipit habitat is not likely, these figures indicate that even 
a fraction of full development could result in significant losses of 
Sprague's pipit habitat. This estimate only includes the impacts from 
the turbines and associated roads. The potential impacts from other 
associated infrastructure (e.g. power lines) is not known, but may 
impact the species (e.g. from power-line strikes). The areas with the 
highest wind potential often overlap with the areas of remaining native 
prairie, making it likely that wind development will focus on the 
remaining suitable Sprague's pipit habitat (U.S. Department of Energy 
2010a, p. 1; Loesch, pers. comm. 2010).
    There is some information suggesting that wind farms adversely 
impact grassland songbirds, a group that is already in decline (Casey 
2005, p. 4; Manville 2009, p. 1). The entire U.S. range of the 
Sprague's pipit is within an area with high potential for wind 
development (American Wind Energy Association 1991, p. 1; U.S. 
Department of Energy 2010a, p. 1). Thousands of acres of Sprague's 
pipit habitat have already been fragmented by wind development (Loesch 
2010, pers. comm.), a trend which is presumably consistent throughout 
the range as the number of wind farms increases (U.S. Department of 
Energy 2010b, entire). Thirty-three States and the District of Columbia 
have requirements or voluntary goals for renewable energy to make up a 
percentage of their energy needs, including North Dakota, South Dakota, 
Minnesota, and Montana (U.S. Department of Energy 2009, entire). 
Mandates for ``green'' energy in States without Sprague's pipits are 
likely to fuel increases in wind development in the Sprague's pipits' 
range because wind power generated in these wind-rich areas are 
generally transmitted out-of-State (e.g. Great River Energy 2010, p. 
1). We anticipate the number of turbines throughout the Sprague's pipit 
range to continue to dramatically increase.
    Oil and gas extraction is ongoing throughout much of the Sprague's 
pipit's range in Canada, and is expected to increase into the future 
(Dale 2010, pers. comm.). Similarly, wind development is increasing 
throughout the Canadian range of the Sprague's pipit (Canadian Wind 
Energy Association 2010, entire; Canadian Environmental Assessment 
Agency - Canadian Environmental Assessment Registry 2010, entire).
    Because of wide-scale energy development across the Sprague's 
pipits' range, we believe that oil, gas, and wind development 
represents a serious threat to the continued existence of the Sprague's 
pipit. Sprague's pipits avoid features in the landscape that are 
structurally different than grassland, so the construction of energy-
related structures negatively impacts the species' use of a wide area. 
The amount and extent of energy development has been increasing rapidly 
and is expected to continue to increase, so energy development will be 
an ongoing and increasing threat into the future.
Roads
    In addition to fragmenting the habitat, roads enable the spread of 
exotic species because vegetative propagules (parts that can sprout 
independently) can be inadvertently transported along roads, while the 
ground disturbance associated with road construction provides sites 
where propagules can readily germinate (Trombulak and Frissell 2000, p. 
24; Simmers 2006, p. 7). Furthermore, the dust and chemical runoff from 
roads allow only tolerant plant species to grow nearby, changing the 
plant composition even if the right-of-way were not actually disturbed 
and reseeded (Trombulak and Frissell 2000, p. 23). Even 20 years after 
reclamation, the nonnative seeds used on reclaimed roadbeds can still 
dominate the area (Simmers 2006, p. 24). These nonnative species spread 
into the nearby prairie, indicating that long-term impacts of road 
construction extend beyond the original footprint of the roadway 
(Simmers 2006, p. 24). Even if vehicles are cleaned before entering an 
area, they pick up nonnative seeds when visiting

[[Page 56036]]

infested sites, and carry them to newly disturbed areas, transporting 
nonnative species throughout the landscape (Dale et al. 2009, p. 195). 
In addition, as discussed under Factor C, roads serve as pathways for 
predators (Pitman et al. 2005, p. 1267). Thus, a secondary impact of 
habitat fragmentation may be an increase in predation.
    The increase in roads throughout the Sprague's pipit's range 
represents a serious and ongoing threat to the species. Because every 
new energy feature requires at least some new road construction, the 
impacts of energy development on the species are closely tied to the 
impacts of road development. Both further fragment the remaining 
suitable habitat, leaving remnant patches that may be too small for the 
nesting of Sprague's pipit. Roads negatively affect the structure and 
make-up of the prairie, and also make grassland habitat more accessible 
to predators, likely decreasing Sprague's pipits' reproductive success.
Migration and Wintering Habitat
    Although there have been few studies of non-breeding Sprague's 
pipits, Sprague's pipits appear to be strongly tied to native prairie 
habitat during the winter (Desmond et al. 2005, p. 442; Emlin 1972, p. 
324). They are occasionally observed in other habitat types, especially 
during migration (Maher 1973, p. 20; Robbins and Dale 1999, pp. 13-14). 
Several researchers have noted the rapid conversion rate to cropland 
and extremely limited area protected in the Chihuahuan desert region 
along the border between the United States and Mexico (Desmond et al. 
2005; pp. 448-449; Maci[acute]as-Duarte et al. 2009, p. 902; Manzano-
Fischer et al. 2006, p. 3820). In the Chihuahuan Desert Region (United 
States and Mexico), an estimated 7 percent of grassland habitat 
remained in 2005 (Desmond et al. 2005, pp. 439, 448). Between 2005 and 
2008, an estimated 30,000 ha (74,000 ac) of this grassland was 
converted (Macias-Duarte et al. 2009, p. 902). In many places where 
native grassland remains, a variety of factors have led to shrub 
encroachment, including overgrazing, elimination of prairie dogs, 
changes in stream flow and the water table due to irrigation, and 
changes in climate patterns (Desmond et al. 2005, p. 448; Manzano-
Fischer et al. 2006, p. 3820; Walker et al. 1981, p. 493). Reversing 
the pattern of woody species invasion is very difficult because once 
established, woody species tend to be stable in the landscape (Whitford 
et al. 2001, p. 9).
    Because Sprague's pipit's presence on the wintering grounds in a 
particular area is related to rainfall the previous year (Dieni et al. 
2003, p. 31; Maci[acute]as-Duarte 2009, p. 901), pipits move to 
different parts of the wintering range annually, with densities 
dependent on local conditions. Therefore, it is likely necessary for 
sufficient suitable habitat to be available throughout the wintering 
range so that areas that are too dry one year may be used when 
conditions improve but are poor elsewhere. With conversion of grassland 
habitat on the wintering grounds, the amount of suitable habitat 
available to Sprague's pipits is shrinking (Maci[acute]as-Duarte 2009, 
p. 896; Manzano-Fischer et al. 2006, p. 3820). Even grassland that is 
not actively converted is becoming unsuitable for Sprague's pipits due 
to widespread changes in grassland management and resulting changes in 
grassland structure. These changes are caused by overgrazing, shrub 
encroachment, and an increase in the biomass of annual grasses, among 
other causes (Drilling 2010, pp. 9-10; Manzano-Fischer et al. 2006, pp. 
3819-3821; Walker et al. 1981, pp. 473-474).
    The Sprague's pipit's wintering habitat has undergone widespread 
conversion to farmland and degradation from management changes since 
pre-colonial times. These changes are likely negatively impacting the 
Sprague's pipit population as a whole. As conversion and degradation 
continue, we expect wintering habitat to be more limiting. However, 
there have not been specific studies examining Sprague's pipits' 
habitat use during migration or on the wintering grounds, so it is not 
possible to determine if the changes to the migration and wintering 
grounds already constitute a threat to the species that may be placing 
the species at risk of extinction now or in the future. However, we 
think the magnitude of loss on the breeding grounds is sufficient to 
determine that the species is at risk of extinction now or in the 
future even in the absence of specific information on the wintering 
grounds.

Summary of Factor A

    The Sprague's pipit is a grassland obligate species that is 
sensitive to fragmentation and that requires relatively large grassland 
patches to form breeding territories. As identified above in our Factor 
A analysis, the native prairie habitat on which Sprague's pipits depend 
has been drastically altered since European settlement, with most of 
the native prairie converted to other uses. Habitat conversion, 
fragmentation, improperly timed mowing, and energy development and 
associated facilities are all contributing, individually and 
collectively, to the present and threatened destruction, modification, 
and curtailment of the habitat and range of the Sprague's pipit. Only 
approximately 1.55 to 1.86 percent of the breeding range remains in 
large enough patches to be used for breeding in the United States and 
only approximately 5 to 6 percent remains suitable in Canada. Land 
conversion and fragmentation of remaining grassland habitat are 
accelerating throughout the species' breeding range. Grassland on the 
wintering range also is rapidly being converted to uses not suitable 
for the species. We anticipate that conversion and fragmentation will 
continue to occur, and are likely to increase, on both the breeding and 
wintering range. As discussed above, the Sprague's pipit population is 
experiencing a long-term decline. As more habitat becomes unsuitable, 
we expect the population decline to continue or to accelerate.
    We have evaluated the best scientific and commercial information 
available regarding the present or threatened destruction, 
modification, or curtailment of the Sprague's pipit's habitat or range. 
Based on the current and ongoing habitat issues identified here, their 
synergistic effects, and their likely continuation in the future, we 
have determined that this factor poses a significant threat to the 
species.

Factor B. Overutilization for Commercial, Recreational, Scientific, or 
Educational Purposes.

    We are not aware of any commercial, recreational, or educational 
uses of the species. Sprague's pipit has not been extensively studied 
for scientific purposes (e.g., Robbins and Dale 1999, p. 1; Davis 2009, 
p. 265). A limited number of studies have involved close observation or 
handling of Sprague's pipit adults, nests, or young (e.g., Sutter et 
al. 1996, pp. 694-696; Davis 2003, pp. 119-128; Dieni and Jones 2003, 
pp. 388-389; Jones et al. 2007; Dohms and Davis 2009, pp. 826-830). 
Work involving radio-transmitter attachment on Sprague's pipit 
nestlings found no evidence that the devices impacted survival, 
although the transmitter may temporarily impact the birds' balance and 
movement (Davis and Fischer 2009, p. 199; Fischer et al. 2010, pp. 1, 
3-5).
    Most research that includes the Sprague's pipit relies on passive 
sampling (e.g., point counts) rather than active handling. The studies 
that involve active handling of adults, nestlings, or nests may impact 
the individuals involved, but are small enough in scale that they are 
unlikely to affect the population as a whole. Passive

[[Page 56037]]

sampling techniques are unlikely to have negative impacts on Sprague's 
pipits.

Summary of Factor B

    We do not have any evidence of risks to Sprague's pipits from 
overutilization for commercial, recreational, scientific, or 
educational purposes, and we have no reason to believe this factor will 
become a threat to the species in the future. Therefore, we find that 
overutilization for commercial, recreational, scientific, or 
educational purposes is not a significant threat to the Sprague's pipit 
now or in the foreseeable future.

Factor C. Disease or Predation.

Disease
    We are not aware of any information to indicate that disease poses 
a significant threat to Sprague's pipits at this time. The 
Intergovernmental Panel on Climate Change (IPCC) (2007, p. 51) suggests 
that the distribution of some disease vectors may change as a result of 
climate change. However, the Service currently has no information to 
suggest that any specific disease may become problematic to Sprague's 
pipit.
Predation
    Predation is thought to destroy up to 70 percent of grassland bird 
nests (Davis 2003, p. 119). The predation rate on Sprague's pipits may 
be lower due to their well-concealed nests and secretive behavior 
(Davis 2003, pp. 124; Davis and Sealy 2000, p. 223; Jones and Dieni 
2007, pp. 117-122). The species' tendency to choose taller vegetation 
and to build covered nests with a runway presumably is at least in part 
an attempt to avoid being seen by predators (Sutter 1997, p. 467), 
although a covered nest may not reduce predation (Jones and Dieni 2007, 
p. 123). Predation has been documented to be the main cause of 
mortality of nestling and fledgling Sprague's pipits (Davis and Fisher 
2009, entire).
    We do not believe that the natural level of predation presents a 
threat to the species. Rather, the predation risk for the Sprague's 
pipit may be unnaturally increased by the fragmentation of habitat 
discussed above under Factor A. Songbird predators tend to travel along 
habitat edges, avoiding prairie areas where escape is more difficult 
(Johnson and Temple 1990, p. 110). Birds that may nest near a habitat 
edge, such as a road, could experience lower nest success because they 
may be more likely to be parasitized by cowbirds (Davis 1994, p. i) and 
because roads may serve as travel routes for predators (Pitman et al. 
2005, p. 1267). The Sprague's pipit's preference for larger patches of 
unfragmented prairie may reduce their susceptibility to predation. 
However, as fewer large patches of grassland are available, predation 
risk to Sprague's pipits may increase.
Cowbird Parasitism
    Cowbird parasitism also leads to Sprague's pipit nest failures, 
because the cowbirds remove or damage host eggs and cowbird young out-
compete the hosts for resources (Davis 2003, pp. 119, 127). Limited 
evidence suggests that Sprague's pipit nests that are parasitized do 
not produce any pipit young (Davis and Sealy 2000, p. 226). Both nest 
predation and cowbird parasitism generally are higher in small remnant 
grassland plots near habitat edges (Johnson and Temple 1990, pp. 106, 
108; Davis 1994, p. i; Davis and Sealy 2000, p. 226), so the Sprague's 
pipit's preference for larger tracts of grassland, when these are 
available, may make the species less susceptible to cowbird parasitism 
than some other grassland species. As with predation, the continued 
loss and fragmentation of native grassland (see discussion under Factor 
A) means that the remaining habitat is more fragmented, likely leading 
to increased levels of cowbird parasitism and predation.
    We are concerned that continued landscape fragmentation will 
increase the effects of predation on this species, potentially 
resulting in a further reduction in Sprague's pipit productivity and 
abundance in the future. However, there is very limited information on 
the extent to which such effects might be occurring.

Summary of Factor C

    We do not find evidence that disease is currently impacting the 
Sprague's pipit, nor do we have information to indicate that disease 
outbreaks will increase in the future. We find that disease is not a 
threat to the Sprague's pipit now and is not expected to become so in 
the future. While the level of predation for all grassland birds is 
high, we do not have information at this time to suggest that predation 
or cowbird parasitism is impacting Sprague's pipits at a level that 
threatens the species. Because Sprague's pipits select large grassland 
patches for nesting, when larger habitat patches are available 
Sprague's pipits may be less susceptible to cowbird parasitism than 
other grassland species. However, the increased fragmentation of 
habitat, as discussed under Factor A, may lead to increased predation 
and cowbird parasitism, and we believe that predation may become a more 
serious factor affecting the species. However, at this time, based on 
the available information we conclude that disease or predation is a 
not significant threat to the spe