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Scope
This assessment examines the biology, ecology,
conservation, and management of the long-billed
curlew with specific reference to the geographic and
ecological characteristics of the USFS Rocky Mountain
Region. Although some of the literature on the species
originates from field investigation outside the region,
this document places that literature in the ecological
and social context of Region 2. Similarly, this
assessment is concerned with reproductive behavior,
population dynamics, and other characteristics of
long-billed curlew in the context of the current
environment. The evolutionary environment of the
species is considered in conducting the syntheses, but
placed in a current context.
In producing the assessment, I reviewed refereed
literature, non-refereed publications, research reports,
and data accumulated by resource management
agencies. Not all publications on long-billed curlew
are referenced in the assessment, nor were all published
materials considered equally reliable. The assessment
emphasizes refereed literature because this is the
accepted standard in science. Non-refereed publications
or reports were used when refereed information was
unavailable, but these were regarded with greater
skepticism. Unpublished data (e.g., Natural Heritage
Program records) were important in estimating the
geographic distribution of this species. These data
required special attention because of the diversity of
persons and methods used in their collection.
Treatment of Uncertainty
Science represents a rigorous, systematic
approach to obtaining knowledge. Competing ideas
regarding how the world works are measured against
observations. However, because our descriptions of
the world are always incomplete and our observations
are limited, science focuses on approaches for dealing
with uncertainty. A commonly accepted approach to
science is based on a progression of critical experiments
to develop strong inference (Platt 1964). However, it
is difficult to conduct experiments that produce clean
results in the ecological sciences. Often, we must rely
on observations, inference, good thinking, and models
to guide our understanding of ecological relations. In
this assessment, I note the strength of evidence for
particular ideas, and describe alternative explanations
where appropriate.
Publication of Assessment on the World
Wide Web
To facilitate the use of species conservation
assessments, they are being published on the Region 2
World Wide Web site (http://www.fs.fed.us/r2/projects/
scp). Placing the documents on the Web makes them
available to agency managers and biologists, and the
public more rapidly than publishing them as reports.
More importantly, Web publication will facilitate
updating and revising the assessments, which will
be accomplished based on protocols established by
Region 2.
Peer Review
In keeping with the standards of scientific
publication, assessments developed for the Species
Conservation Project have been externally peer reviewed
prior to their release on the Web. This assessment was
reviewed through a process administered by the Society
for Conservation Biology, which chose two recognized
experts (on this or related taxa) to provide critical input
on the manuscript.
M
ANAGEMENT
S
TATUS AND
N
ATURAL
H
ISTORY
Management Status
Long-billed curlews are endemic breeding birds
of the mixed-grass and shortgrass prairies of the Great
Plains. Although the species is not federally listed or
a candidate for listing under the Endangered Species
Act, a decline in abundance on both the breeding
and wintering grounds, has lead to the following
conservation status rankings:
v
Natural Heritage Program (NHP) global rank
of G5 (globally secure, but indication of long-
term population declines)
v
USDA Forest Service Region 2 Sensitive
Species
v
Bureau of Land Management sensitive
species rankings of 1 (under status review
by U.S. Fish and Wildlife Service) and 3
(typically small and dispersed populations)
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v
U.S. Fish and Wildlife Service (USFWS)
Bird of Conservation Concern throughout
its breeding and wintering ranges (ranked
nationally in USFWS Regions 1, 2, 4, and 6,
and in all Bird Conservation Regions where
the species occurs) (U.S. Fish and Wildlife
Service 2002)
v
Partners in Flight (PIF) Species Assessment
Breeding Scores of 20 (moderately high
priority) and 24 (significant declines) for
the Wyoming Basin and Central Shortgrass
Prairie physiographic areas (S86 and S36),
respectively
v
PIF priority bird species in northern shortgrass
prairie (Wyoming, Montana; physiographic
area 39), central shortgrass prairie (Colorado;
physiographic area 36), Pecos and Staked
Plains (eastern New Mexico, western Texas;
physiographic area 55), central mixed-grass
prairie (Nebraska; physiographic area 34),
Columbia Plateau shrubsteppe (Washington,
Oregon, Idaho; physiographic area 89),
Basin and Range (Nevada, western Utah,
southeastern Idaho; physiographic area 80),
and Level 1 species in need of conservation
action (Wyoming)
v
Wyoming NHP rank of S3B (rare or local,
or restricted range) and Wyoming Species of
Concern
v
Colorado NHP rank of S2B/SZN (breeding
populations state imperiled) and a Colorado
Division of Wildlife Species of Special
Concern
v
listed as vulnerable in Canada (De Smet
1992)
v
categorized as “highly imperiled” in U.S.
Shorebird Conservation Plan (Brown et al.
2000).
Existing Regulatory Mechanisms,
Management Plans, and Conservation
Strategies
Laws, regulations, and management direction
Although the long-billed curlew is on the Region
2 Regional Forester’s Sensitive Species List, there are
no existing legal mechanisms, management plans,
or conservation strategies that apply specifically to
this species. It does receive protection under several
laws, including the Migratory Bird Treaty Act (1918),
the National Forest Management Act (1976), and the
Neotropical Migratory Bird Conservation Act (2000).
The Migratory Bird Treaty Act prohibits, with certain
exceptions, the pursuit, hunting, capture, killing, taking,
sale, purchase, transport, receipt for shipment, or export
of any migratory bird, or the nest or eggs of such
birds (16 U.S.C. 703; http://laws.fws.gov/lawsdigest/
migtrea.html). Furthermore, treaties formed because
of the Act require the federal government to protect
ecosystems of special importance to migratory birds
against pollution, detrimental alterations, and other
environmental degradations.
The National Forest Management Act and its
implementing regulations and policies require the
USFS to sustain habitats that support healthy, well-
distributed populations of native and desired non-native
plant and animal species on National Forest System
lands. Legally required activities include monitoring
population trends of management indicator species
in relationship to habitat change, determining effects
of management practices, monitoring the effects of
oil and gas development and off-road vehicles, and
maintaining biological diversity. By policy, sensitive
species designation is a tool to help ensure that species
with identifiable viability concerns are conserved.
The Neotropical Bird Conservation Act provides
grants to U.S., Latin American, and Caribbean
organizations for the conservation of birds that breed in
the United States and winter south of the U.S.-Mexico
border. It encourages habitat protection, education,
research, monitoring, and the long-term protection
of Neotropical migratory birds (http://laws.fws.gov/
lawsdigest/neotrop.html).
The standards and guidelines of the Forest
Service Government Performance Results Act ensure
that resources are managed in a sustainable manner. The
National Environmental Policy Act requires agencies
to specify environmentally preferable alternatives in
land use management planning. Additional laws with
which USFS management plans must comply are the
Endangered Species, Clean Water, Clean Air, Mineral
Leasing, Federal Onshore Oil and Gas Leasing Reform,
and Mining and Minerals Policy acts; all are potentially
relevant to long-billed curlew conservation.
National monitoring and conservation-related
programs relevant to the long-billed curlew include
the North American Breeding Bird Survey (BBS),