Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan and Environmental Assessment

              Draft Comprehensive
Conservation Plan and
Environmental Assessment
U.S. Fish & Wildlife Service
Crescent Lake
National Wildlife Refuge
CCPs provide long-term guidance for management decisions and
set forth goals, objectives, and strategies needed to accomplish
refuge purposes and identify the Service’s best estimate of future
needs. These plans detail program planning levels that are
sometimes substantially above current budget allocations and, as
such, are primarily for Service strategic planning and program
prioritization purposes. The plans do not constitute a commitment
for staffing increases, operational and maintenance increases, or
funding for future land acquisition.
CRESCENT LAKENATIONALWILDLIFE REFUGE
AUNIT OF THENATIONALWILDLIFE REFUGE SYSTEM
DRAFT
COMPREHENSIVE CONSERVATION PLAN
AND ENVIRONMENTAL ASSESSMENT
Prepared by
U.S. Fish & Wildlife Service
Crescent Lake National Wildlife Refuge
115 Railway Office Complex
Scottsbluff, NE 69363
Summary
Crescent Lake National Wildlife Refuge is located in Garden County on
the eastern edge of the Nebraska Panhandle. It lies on the southwestern
edge of the 19,300 square mile Nebraska Sandhills, the largest sand dune
area in the Western Hemisphere and one of the largest grass-stabilized
regions in the world. The Sandhills are characterized by rolling,
vegetated hills and inter-dunal valleys which are oriented in a northwest
to southeast direction. Many shallow lakes and marshes are interspersed
in the lower valleys. Native grasses predominate. Wildlife diversity,
except large ungulates and their predators, is relatively unchanged since
early settlement.
There are 21 wetland complexes on the Refuge totaling approximately
8,251 acres or about 18 percent of the total area. These wetlands are a
mixture of shallow lakes, marshes, seasonal wetlands, wet meadows and
a small stream resulting from Refuge management activities.
The Sandhills are within a wide transitional zone called the Mixed Grass
Prairie which lies between Tallgrass Prairie to the east and Short Grass
Prairie to the west. Although precipitation is typical of the semi-arid
Mixed Grass Prairie, the Sandhills are characterized by post-climax,
tallgrass species typical of a greater moisture regime (Oosting 1948;
Keeler, et al 1980).
The Nebraska Sandhills are one of the few large native prairie areas in
the United States that have not been substantially converted to
farmland or otherwise modified. Thus, most of the plant and animal
species present when settlement began are still present today.
This is a 15-year Plan, but only the goals will remain static. Objectives
and strategies are based on present knowledge and reflect known needs.
They may change, as may specific management actions, as knowledge
and needs change. Public involvement will be sought for any significant
amendments.
It is also important to understand that individual objectives cannot be
taken out of context. It is the mixture of objectives that will produce the
desired results. Generally speaking, on Crescent Lake Refuge, where
the legal mandate is to serve as a “refuge and breeding ground for birds
and other wild animals,” habitat is managed to support or produce birds
and other wildlife. However, because it is the habitat over which wildlife
managers have most control, a clear understanding must also occur of
the kinds and amounts of habitat needed to support that wildlife. Public
use and environmental education are also important functions of the
Refuge. Thus, it is important to know what kinds and how much public
use can be allowed and remain compatible with the wildlife purposes and
objectives.
The main goals of the CCP are:
Endangered, Threatened, and Candidate Species
■ Goal: Contribute to the preservation and restoration of endangered
flora and fauna that are or were endemic to the Crescent Lake
Refuge area.
Upland Habitat
■ Goal: Preserve, restore, and enhance the ecological diversity of
indigenous flora and fauna of the physiographic region described as
the Sandhills Prairie.
Wilderness
■ Goal: Preserve, restore, and enhance the ecological diversity of
indigenous flora and fauna of the physiographic region described as
the Sandhills Prairie, while maintaining and enhancing the
wilderness quality.
Wetland Habitat
■ Goal: Maintain natural and artificially managed permanent and
semipermanent wetlands to provide habitat for migratory waterfowl,
shorebirds, wading birds, and associated wetland-dependent species.
Fish and Wildlife
■ Goal: Preserve, restore, and enhance the ecological diversity and
abundance of migratory birds and other indigenous fish and wildlife
with emphasis on grassland-dependent species.
Interpretation and Recreation
■ Goal: Provide visitors an opportunity to enjoy, learn about and
utilize fish and wildlife in a setting that emphasizes an undisturbed
natural environment and minimum human interaction.
Community Involvement / Support Systems
■ Goal: Interact with communities and organizations to create
mutually beneficial partnerships.
Meadowlark © Cindie Brunner
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Table of Contents
Purpose and Vision . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
I. Introduction / Background
Purpose of a Comprehensive Conservation Plan . . . . . . . . . . . . . . . . 2
Refuge History - an Overview
Establishment and Administration . . . . . . . . . . . . . . . . . . . . . . . . 2
Wildlife and Habitat Management . . . . . . . . . . . . . . . . . . . . . . . . . 6
Cultural Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Public Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
The National Wildlife Refuge System
Mission and Goals and Guiding Principles . . . . . . . . . . . . . . . . . . . . . 10
Fish and Wildlife Service Mission . . . . . . . . . . . . . . . . . . . . . . . . 10
National Wildlife Refuge System Mission . . . . . . . . . . . . . . . . . 10
National Wildlife Refuge System Goals . . . . . . . . . . . . . . . . . . . 11
Legal and Policy Guidance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Existing Partnerships . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
II. Planning Process
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Planning Assumptions and Limitations
Proposed Wilderness and Research Natural Areas . . . . . . . . . 13
Planning Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Wilderness Proposal and Research Natural Areas . . . . . . . . . . 14
Endangered Species . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Public Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Hunting and Fishing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Invasive Species . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Bison Reintroduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Lands of Interest . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Staffing and Funding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
III. Refuge and Resource Descriptions
Socio-economic Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Geographic / Ecosystem Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Climate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Soils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Geology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Refuge Resources
Water and Wetlands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Vegetation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Vegetative Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Endangered Plants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Plant Species of Management Concern . . . . . . . . . . . . . . . . 23
Wildlife . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Endangered and Threatened Species . . . . . . . . . . . . . . . . . . 23
Birds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Mammals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Amphibians and Reptiles . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Fish . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Cultural Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Public Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
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IV. Refuge Goals, Objectives, and Strategies
Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Endangered, Threatened and Candidate Species . . . . . . . . . . . . . . . 32
Special Places . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Upland Habitat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Wilderness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Wetland Habitat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Fish and Wildlife . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Public Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Cultural Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Lands and Facilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Community Involvement / Support Systems . . . . . . . . . . . . . . . . . . . 60
Lands of Interest . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
V. Implementation and Monitoring
Funding and Personnel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Refuge Management Policies and Guidelines . . . . . . . . . . . . . . . . . . 63
Partnership Opportunities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Monitoring and Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Plan Amendment and Revision . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Environmental Assessment . . . . . . . . . . . . . . . . . . . . . . EA-65
Appendices
A. Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
B. Literature Cited / References . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
C. Legal and Policy Guidance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
D. Operations and Maintenance Needs . . . . . . . . . . . . . . . . . . . . . . . 97
E. Compatibility Determinations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
F. Crescent Lake NWR Species List . . . . . . . . . . . . . . . . . . . . . . . 102
G. Minimum Tools for Wilderness Management . . . . . . . . . . . . . . 109
H. Species of Special Interest . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
I. Step-down Management Plans . . . . . . . . . . . . . . . . . . . . . . . . . . 110
J. Section 7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
K. List of Preparers / Review Team . . . . . . . . . . . . . . . . . . . . . . . . 111
L. Mailing List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
Maps
1. Vicinity Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Base Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3. Region 6 Ecosystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4. Vegetative Habitat Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5. Public Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Figures
Figure 1. Penstemon Populations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Figure 2. Average Peak Waterfowl Populations by Species During
Fall Migration, 1985-95 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Figure 3. 1997-1999 Raptor Breeding Survey Results . . . . . . . . . . 26
Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002 1
Purpose and Vision
Legal Purpose
Crescent Lake National Wildlife Refuge was established on March 16,
1931, by Executive Order 5597 which defined the legal purpose as an
area “. . . reserved and set apart . . . as a refuge and breeding ground for
birds and wild animals.”
It is important to understand this legal purpose, particularly because it
includes all wild animals, not just migratory birds. It is the hub around
which planning, management actions, and compatibility determinations
revolve.
Vision
“I am the grass; I cover all . . .
“I am the grass
Let me work”
- Carl Sandberg (Grass)
A sea of grass in a sea of grass, Crescent Lake National Wildlife Refuge
was established primarily for the concentration of native prairie and
associated wetlands which, together, attract a wide variety of wildlife,
particularly migratory birds. But, like all national wildlife refuges,
Crescent Lake Refuge is not an island, independent of what goes on
around it. It is part of larger and dynamic social, economic and biological
communities, communities that also affect wildlife that use the Refuge.
Unlike many Refuges, however, surrounding land use, principally cattle
grazing, is relatively stable, public use is relatively low, and there are
few threats from the outside.
Thus, we envision a Refuge about the same size it is now, the purpose of
which is to maintain in perpetuity a representative sample of the native
prairie and wildlife associated with this part of the Nebraska Sandhills.
We see habitat in excellent condition, fewer exotic plants, and a healthy
and growing population of blowout penstemon, an endangered plant. We
see a visiting public which values the solitude and for which relatively
few but high quality learning and recreational facilities are available. We
see about half of the Refuge as a National Wilderness Area which
supports bison, a species not present in the area in a wild state for over
100 years. We see the Refuge doing its part to support migratory birds
enjoyed by people in States up and down the Central Flyway. We see
active partnerships with surrounding landowners to help them maintain
habitat on private lands while engaged in sustained, profitable
agriculture. We see the Refuge as a contributing part of the Nebraska
Sandhills.
2 Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002
I. Introduction /Background
Purpose of a Comprehensive Conservation Plan
The National Wildlife Refuge System Improvement Act of 1997 requires
that Comprehensive Conservation Plans (CCP) be prepared for each unit
of the National Wildlife Refuge System, and that the public be involved
in preparing and revising these plans.
Comprehensive planning creates an opportunity to meet with neighbors,
customers, and other agencies to identify and discuss natural resource
issues and help ensure the plan meets the changing needs of wildlife and
people. This Plan discusses history, goals and objectives, and the general
direction refuge management will take over the next 15 years. For a
complete discussion of the planning process, refer to the “Draft Planning
Policy Pursuant to the National Wildlife Refuge System Improvement
Act of 1997” (copies available at the Refuge Headquarters).
Refuge History - an Overview
Establishment and Administration
The 45,849-acre Crescent Lake National Wildlife Refuge (Refuge),
established in 1931, is located 28 miles north of Oshkosh, Nebraska in
Garden County at the southwestern end of the Nebraska Sandhills (Map
1). It is administered by the U.S. Fish & Wildlife Service (Service) as
part of the Crescent Lake/North Platte National Wildlife Refuge
Complex, and is within the Central Flyway. The Complex headquarters
is 100 miles to the west in the City of Scottsbluff.
The initial Refuge was 36,920 acres, acquired primarily from one large
ranch. Additional lands were acquired between 1932 and 1937. Most
lands were acquired or exchanged under the authority of the Migratory
Bird Conservation Act (45 Stat. 1222). About 2,566 acres were acquired
under the Resettlement Administration (Executive Order 7027, April 30,
1935), a drought and depression relief program.
The Nebraska Sandhills were settled largely as a result of the Kincaid
Act of 1904, a modification of the Homestead Act to allow settlers 640
acres in “less productive” areas. As a result, a homestead existed in
almost every meadow. However, 640 acres was not a viable farm/ranch
unit in the Sandhills, and land was soon consolidated into larger units.
Today, the Sandhills are home to some of the largest ranches in the
country. Because of the large acreage required to support economically
viable units, Garden County is among the least densely populated areas
in the continental United States. Most of the Refuge location names
originated from the early homesteaders.
Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002 3
Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002 5
The earliest government actions on the Refuge were tree plantings and
small construction projects by the Civilian Conservation Corps (CCC)
and the Works Projects Administration (WPA). The CCC built several
buildings still in use today at the Refuge headquarters. The WPA built
roads, fences, and other facilities, such as the fire tower and buildings, at
the headquarters site.
Initially, the staff at Crescent Lake Refuge was also responsible for the
2,909-acre North Platte Refuge, 100 miles to the west. The latter was not
staffed until 1990 when the Crescent Lake/North Platte National
Wildlife Refuge Complex was officially formed. The Complex
headquarters was moved to Scottsbluff in 1993.
All lands around the Refuge are in private ownership except for a small
ranch on the west boundary, purchased in 1984 by The Nature
Conservancy for preservation of the blowout penstemon (an endangered
plant). The only other public land in Garden County is Ash Hollow State
Historical Park, 50 miles to the southeast. In March 2000, media
entrepreneur Ted Turner purchased a large ranch adjacent to the east
boundary of the Refuge; plans for this area are not yet known, although
Mr. Turner has placed bison on holdings in Nebraska, Montana, and
other states.
Because of its remote location, the Refuge must provide housing for
employees. Currently, housing is available for five permanent and four
temporary employees. Four service and equipment storage buildings,
together with the residences, are clustered in a compact headquarters
area (Map 2). Additional equipment storage and two buildings are
located across the county road about one-half mile to the east.
6 Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002
Wildlife and Habitat Management
Special Places In 1972, a 24,502-acre area was proposed for inclusion in
the National Wilderness Preservation System (Map 2). Although
Congress has not acted on the proposal, no development has occurred in
the area since 1972.
Two Research Natural Areas were established in 1955 by a Director’s
Order and included on the National List of Research Areas (Map 2). The
Goose Lake RNA (940 acres) has not been grazed, hayed, or
intentionally burned since 1948. The Hackberry Lake RNA (172 acres)
has not been disturbed since 1951, except for a 60-acre spring burn in
1983 and a short duration spring graze in 1988.
Populations Management Direct populations management consisted
primarily of providing sanctuary and controlling predators. Predator
control was a significant management activity until 1994, when is was
suspended due to staffing limitations and modest results. Public trapping
has occurred sporadically. It ended in 1954 when it became economically
unfeasible, was revived in the 1980s, but again faded out with low fur
prices.
Wetland Management The Refuge has about 8,250 acres of wetlands;
there are no permanent natural streams. Manipulation of water levels is
possible only on nine lakes and has been used to control shoreline
vegetation and create open shoreline for migratory birds. Pothole
blasting occurred in the late 1960s to create additional waterfowl
breeding habitat; results were limited and the effort was discontinued
after a few years. Natural filling of wetlands and invasion of phragmites,
an exotic plant, are emerging problems.
Upland Management The agreement for purchase of the original 36,920
acres allowed previous owners to continue to graze at no cost for 10
years. The only restriction was that no more than 4,000 cattle could be on
the Refuge at any one time. By the end of the 10 years, most of the
Refuge was seriously overgrazed. During World War II, the Refuge was
leased to surrounding ranches for cattle grazing to help meet wartime
needs. Although the stocking rate then was half that on surrounding
commercial lands, Refuge grasslands made little recovery. After the
War, grazing gradually declined.
Although the Refuge has largely recovered from overgrazing in the past,
grazing remains an important tool. Today, native prairie management
consists of a combination of rest, grazing, and prescribed burning.
Prescribed burning was first used as a management tool in 1984 and has
obvious limitations in this sea of grass; about 500 acres are planned for
burning annually.
Noxious weeds are a ubiquitous problem, and the Refuge is no exception.
Fortunately, surrounding private lands are well-managed and the
problem is limited to Canada thistle. Leafy spurge was eradicated from
the Refuge in 1994.
There are about 80 acres of trees on the Refuge, most of which were
planted by the CCC in the 1930s. Trees add diversity; however, with the
exception of cottonwoods and willows, they are not a normal part of the
Sandhills Prairie. There is no active management and the acreage is
steadily declining through natural mortality.
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Cultural Resources
Historic, archaeological, and paleontological resources are protected by
Federal laws. No formal, systematic cultural resource surveys have been
conducted on the Refuge. The buildings constructed by the CCC or WPA
are more than 50 years old and qualify for preservation.
Public Use
Recreation and Education Portions of the Refuge have always been open
for hunting, fishing, wildlife observation, and general nature-oriented
activities. A Special Use Permits can be used to allow the public to trap.
The Refuge is isolated (Oshkosh, population 1,100, is the nearest town
and 28 miles away) and accessible by few and relatively rough roads.
This isolation limits the number of visitors but is an important and
desirable quality for most who do come. Public use averages about 8,000
visitors per year.
Facilities were always minimal and, even today, are limited to one auto
tour route, two graveled boat ramps, two fishing piers, a public rest
room, modest interpretive displays at the headquarters, and kiosks at
the entrances.
Originally, Refuge lakes did not contain sport fish. Today, three lakes
support sport fisheries which are used by over 5,000 anglers annually.
The Nebraska Game and Parks Commission (NGPC) manages sport
fisheries with concurrence of the refuge manager.
Hunting has always occurred on the Refuge and has grown to about 600
visits per year.
Economic Use As mentioned above, the Refuge was heavily grazed until
the mid-1940s. Since about 1970, grazing has been considered a tool for
wildlife management and the amount of grazing declined as grassland
improved and native prairie conditions were restored. The current
practice of grazing the meadows 1 year out of 6 and the uplands 1 year
out of 20 was initiated in 1993. In the past, as many as 20 permittees
grazed cattle on the Refuge annually and the amount of grazing
exceeded 24,000 animal unit months (AUMs). Today, only 3 to 5
permittees use the Refuge in any given year and grazing is limited to
about 2,500 AUMs. Grazing fees are established through competitive
bidding and are lower than those in much of the Sandhills because
Refuge grazing areas are difficult to access.
10 Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002
The National Wildlife Refuge System
Mission and Goals and Guiding Principles
The National Wildlife Refuge System (Refuge System) is the world’s
largest collection of lands set aside specifically for wildlife. The first unit
of the System, a 3-acre pelican and heron rookery in Florida, was created
in 1903 by President Theodore Roosevelt. Today, the System includes
nearly 540 national wildlife refuges, thousands of small wetlands and
other special management areas encompassing more than 95 million
acres and located in all 50 States and a number of U.S. Territories.
The Refuge System provides habitat for endangered species, migratory
birds, species of management concern (see Glossary and Appendix H)
and other “trust resources” for which the Federal government is
ultimately responsible. It also provides habitat for resident wildlife and
offers wildlife-dependent recreation for over 34 million visitors annually.
Fish and Wildlife Service Mission
“To work with others to conserve, protect, and enhance fish and
wildlife and plants and their habitats for the continuing benefit
of the American people.”
To fulfill this mission, Congress has charged the Service with conserving
and managing migratory birds, endangered species, anadromous and
interjurisdictional fish, and certain marine mammals. The Service carries
out these responsibilities through several functional entities, one of
which is the National Wildlife Refuge System.
National Wildlife Refuge System Mission
“To administer a national network of lands and waters for the
conservation, management, and where appropriate, restoration
of the fish, wildlife, and plant resources and their habitats
within the United States for the benefit of present and future
generations of Americans” (National Wildlife Refuge System
Improvement Act of 1997, Public Law 105-57).
Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002 11
National Wildlife Refuge System Goals
1. To fulfill our statutory duty to achieve refuge purpose(s) and further
the System mission.
2. Conserve, restore where appropriate, and enhance all species of fish,
wildlife, and plants that are endangered or threatened with
becoming endangered.
3. Perpetuate migratory bird, interjurisdictional fish, and marine
mammal populations.
4. Conserve a diversity of fish, wildlife, and plants.
5. Conserve and restore, where appropriate, representative ecosystems
of the United States, including the ecological processes
characteristic of those ecosystems.
6. To foster understanding and instill appreciation of fish, wildlife,
and plants, and their conservation, by providing the public with
safe, high-quality, and compatible wildlife-dependent public use.
Such use includes hunting, fishing, wildlife observation and
photography, and environmental education and interpretation.
While individual refuges are important in and of themselves, they are
even more important for their collective benefits as a network. Together,
national wildlife refuges form a network of lands spanning the entire
continent - supporting birds migrating from Alaska and Canada to the
southern States and points south, preserving trust resources, and
providing enjoyment for people throughout the United States and
neighboring countries. Together, they help prevent species from
becoming threatened or endangered by securing habitat in all or portions
of a species range. Thus, the network is critical - a deficiency in one
location may affect wildlife in other locations.
Legal and Policy Guidance
National wildlife refuges are guided by: The mission and goals of the
National Wildlife Refuge System; the legal purpose of the specific refuge
unit as described in the establishing legislation or executive orders;
International Treaties; Federal laws and regulations; and Service
policies. Key concepts and guidance for the System are included in the
National Wildlife Refuge System Administration Act of 1966, The
Refuge Recreation Act of 1962, Title 50 of the Code of Federal
Regulations, the Fish and Wildlife Service Manual, Executive Order
12996 (March 23, 1996) and, most recently, the National Wildlife Refuge
System Improvement Act of 1997. Appendix C contains a partial list of
Federal laws governing administration of the System.
Crescent Lake Refuge is also guided by a number of agreements with
other agencies and by the conditions presented in the Environmental
Assessment (following Draft CCP) and Compatibility Determinations
(Appendix E).
12 Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002
Important Concepts for Management of National Wildlife Refuges
Compatibility. “Compatibility” is an important legal concept. The
National Wildlife Refuge System Administration Act of 1966 allowed
public use of any area within the System, provided that such use was
“compatible” with the major purposes for which such areas were
established. The concept was further defined and strengthened by the
National Wildlife Refuge System Act of 1997. Thus, by law, all uses of
national wildlife refuges, including land management activities and
wildlife-dependent recreation, must be formally determined to be
“compatible.” A compatible use is defined as one that, in the professional
judgement of the refuge manager, will not materially interfere with or
detract from the fulfillment of the mission of the System or the purposes
of the refuge. Professional judgement is further defined as a determination
that is consistent with sound fish and wildlife management and
administration practices, available science, available resources (including
funding, personnel, facilities, and other infrastructure), and adherence
with applicable laws. See Appendix E for a synopsis of compatibility
determinations for the major uses allowed on Crescent Lake Refuge.
Wildlife as Priority. The National Wildlife Refuge System Improvement
Act of 1997 states that wildlife conservation is the priority of the System.
It amends the Refuge System Administration Act by including a unifying
mission for the System, a formal process for determining compatible
uses, and a requirement that each refuge will be managed under a
Comprehensive Conservation Plan. Further, the Act defines
wildlife-dependent recreational uses as: hunting and fishing, wildlife
observation and photography, environmental education and
interpretation. (Specific details regarding these and other amendments
are available through the Refuge or Regional Office.)
Partnerships and Public Involvement. Executive Order 12996 (March
23, 1996) also provides important guidance. Among other things it:
stresses the importance of partnerships with Federal and State agencies,
Tribes, organizations, industry, and the general public; and, mandates
public involvement in decisions on acquisition and management of refuges.
Existing Partnerships
Partnerships with local, State and Federal Agencies, private
conservation organizations, and landowners are important not only for
achieving and sustaining Refuge objectives but to assure the Refuge is
an active member of the community and contributes to the broader
objectives of that community. Existing partnerships include:
■ Nebraska Game and Parks Commission - Fisheries and wildlife
management/Law enforcement
■ University of Nebraska - Blowout penstemon recovery
■ Earlham University - Reptile and amphibian research
■ Central Panhandle Mutual Aid Association - Fire suppression and
other emergencies
■ The Nature Conservancy - Blowout penstemon recovery
■ North Platte Valley Sportmans Association - National Fishing Day
activities
■ Natural Resource Conservation Service - Wetland Reserve Program
■ National Weather Service - Weather station data
■ Nebraska and Pine Ridge National Forests - Interagency Fire
Agreement
■ U.S. Geological Survey - Water resources management
■ Local landowners - FWS Partners for Fish and Wildlife Program
Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002 13
II. Planning Process
Description
The project leader for the Crescent Lake/North Platte National Wildlife
Refuge Complex and the manager of the Crescent Lake Refuge were
assigned primary responsibility for planning in May 1998. An open
house/scoping session was held in Oshkosh on July 16, 1998, to inform the
public of the planning process and to seek ideas on Refuge programs and
issues. About 150 invitations were mailed to local and national
stakeholders (educators, permittees, neighbors, other agencies and non-profit
organizations). The general public was also invited through widely
published/broadcast news releases. Information could also be obtained
by contacting the Refuge Manager and comments could be submitted in
writing.
Refuge staff also met personally with the Alliance Office of the Nebraska
Game and Parks Commission (NGPC), Wildcat Audubon Society, the
North Platte Valley Sportsmans Association, the Alliance Rotary Club
and the Scottsbluff Lions Club to discuss the CCP process.
In November 1998, the Project Leader formed an interdisciplinary team
to provide input and critical review (Appendix K).
The final CCP will guide management of the Crescent Lake Refuge for
the next 15 years. It will be used to prepare and revise step-down
management plans, performance plans, and budget requests. The Plan
will be reviewed during routine Refuge inspections and programmatic
evaluations. When changes are needed, the level of public involvement
and associated NEPA documentation will be determined by the Project
Leader. The entire plan will be formally reviewed and revised at least
every 15 years.
Planning Assumptions / Limitations
Proposed Wilderness Area
The 24,502-acre proposed Wilderness Area, until accepted or rejected by
Congress, must be managed as if it was wilderness; only “minimum
tools” can be used (see Section IV and Appendix G).
Research Natural Areas
The two officially designated RNAs (1,076 acres) are to remain free of
human disturbance, including habitat management and public use.
14 Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002
Planning Issues
The following issues were identified during the public scoping process
and/or discussions with review team members. Some additional
information is available in the Environmental Assessment.
Wilderness Proposal and Research Natural Areas (see previous page)
Endangered Species. The Refuge is within the range of the blowout
penstemon, a federally-listed endangered plant, and plays an important
role in its survival.
Public Access. The Refuge is accessible only by relatively narrow, rough
roads; most interior roads are passable only with four-wheel-drive
vehicles.
Hunting and Fishing. The Refuge is open to deer and upland bird
hunting but not waterfowl.
Invasive Species. Canada thistle exists in varying densities throughout
the Refuge, including the proposed Wilderness Area and Research
Natural Areas. Phragmites is an aggressive wetland invader.
Bison Reintroduction. Bison were once part of the Sandhills Prairie
ecosystem and should be considered for reintroduction into the proposed
Wilderness Area.
Lands of Interest. Several adjacent areas are potentially important for
the endangered blowout penstemon, wetland values, and migratory birds
and are candidates for additional protection.
Staffing and Funding. Several people expressed concern that funds
would never be available to staff the Refuges and implement the Plan.
Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002 15
III. Refuge and Resource
Descriptions
Socio-economic Environment
Crescent Lake Refuge is located in Garden County on the eastern edge
of the Nebraska Panhandle, an 11-county, 14,000-square-mile region with
a population of about 90,000 people. Basic economic activities in Garden
County include irrigated and dryland farming, cattle feeding, and
ranching.
According to the Nebraska Panhandle Economic Development Report
(Panhandle Area Dev. Dist., undated ca. 1998), the population of Garden
County decreased from 2,460 in 1990 to 2,224 in 1997, a decrease of about
10 percent. The population in the year 2010 is projected at 1,707, a
decrease of more than 20 percent from 1997; similar trends are projected
for much of the surrounding rural area. Only the major population
centers, such as Scottsbluff/Gering (100 miles to the west), project
growth of any significance.
Geographic / Ecosystem Setting
Crescent Lake Refuge lies on the southwestern edge of the 19,300
square mile Nebraska Sandhills, the largest sand dune area in the
Western Hemisphere and one of the largest grass-stabilized regions in
the world. The Sandhills are characterized by rolling, vegetated hills and
inter-dunal valleys which are oriented in a northwest to southeast
direction. Many shallow lakes and marshes are interspersed in the lower
valleys. Native grasses predominate. Wildlife diversity, except large
ungulates and their predators, is relatively unchanged since early
settlement.
About 177,000 acres of open water lakes, shallow marshes and fens, and
nearly 1,130,000 acres of wet meadows remain in the Sandhills. Most
wetlands are freshwater; about 10 percent are alkaline. They range in
size from 1 to 2,300 acres, but 80 percent are less than 10 acres
(LaGrange 1997). Many wetlands have been drained in attempts to
increase hay production. Estimates of the amount drained range from 15
percent (McMurtrey and Craig 1969) to 46 percent (USFWS 1986).
Wetland drainage continues to this day (Bleed and Flowerday 1989).
The Fish and Wildlife Service operates under an “ecosystem approach to
resource management” and, for organizational purposes, has identified
watershed-based ecosystems. The Crescent Lake Refuge is within the
Platte-Kansas Rivers Ecosystem (Map 3).
Climate
Climate of the Sandhills is characteristic of the central Great Plains - cold
winters, hot summers, and frequent thunderstorms from spring to late
summer. Annual precipitation ranges from 17 to 23 inches (Wilhite and
Hubbard 1989), and is coupled with high evapo-transpiration rates. The
Refuge has operated an official weather station since 1935. Precipitation
on the Refuge averages 16.8 inches and temperatures have ranged from
minus 46 to 109 degrees Fahrenheit. Since 1976, relatively high
precipitation has resulted in positive net moisture balances (annual
precipitation minus open pan evaporation) in most years.
16 Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002
Soils
Most soils are wind-laden sands that have not been held in place long by
vegetation. They are light colored and have little organic matter. Soils in
basins, valleys, and wet meadows have thicker and darker surface layers
and more organic matter than soils found in the hills. The main soil types
are dune sand, Valentine sands, Valentine-loamy sands, and Gannett
loamy sands. Rainfall is quickly absorbed and causes little erosion; soil
evaporation rates are low. Native grasses grow well under these
conditions, but soil exposed by overgrazing or plowing is subject to wind
erosion (Layton, et al 1956).
Geology
During the Cretaceous era, a shallow sea covered the area of the Sandhills.
When the sea receded, large valleys were formed which today are covered
with sand. The geological processes are not well understood because of
that sand cover. The exact time is debated, but somewhere between
21,000 and 8,000 years ago, water deposited sand which later began
shifting as a result of climatic changes. This blowing sorted the alluvial
deposits; fine material was carried out of the area and coarse material
was left behind, resulting in the uniform particle size typical of wind
deposited dunes (Bleed and Flowerday 1989).
Refuge Resources
Water and Wetlands
The Nebraska Sandhills overlay the High Plains Aquifer, commonly
referred to as the Ogallala Aquifer. This groundwater is the source of
wetlands in low areas and valleys and is the driving force supporting the
ecological diversity and integrity of the Sandhills.
There are 21 wetland complexes on the Refuge totaling approximately
8,251 acres or about 18 percent of the total area (Map 4). These wetlands
are a mixture of shallow lakes, marshes, seasonal wetlands, wet
meadows and a small stream resulting from Refuge management
activities. They were classified as follows by the Fish and Wildlife
Service (USFWS, Sandhills Wetlands 1986):
Type II, Fresh Meadows 4,755 acres
Type III, Shallow Fresh Marshes 1,154 acres
Type IV, Fresh Marshes 309 acres
Type V, Open Fresh Water 2,033 acres
A few, small alkaline wetlands also exist. These were not specifically
identified as such by the inventory and total about 413 acres.
Submergent and emergent wetland vegetation ranges from sparse to
dense depending on soils and alkalinity. Emergent vegetation includes
cattail, bulrush, and phragmites. Vegetation bordering wetlands is
primarily grasses and sedges. A few lakes have associated groves of
cottonwood and willow trees, usually on the north shores.
Most Refuge wetlands rise and fall with precipitation and groundwater
levels. Since 1981, precipitation has been above average resulting in
record water levels. Control structures and elevation gauges have been
installed on nine lakes, but water levels can be increased significantly on
only five that are connected to a ditch which drains a private marsh
north of the Refuge. Gauges on Island Lake record natural fluctuations.
The U.S. Geological Survey has many groundwater survey wells on the
Refuge which are used to study the complex groundwater hydrology of
the area; the Refuge staff monitors about 25 of these.
Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002 17
Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002 19
Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002 21
Vegetation
The Sandhills are within a wide transitional zone called the Mixed Grass
Prairie which lies between Tallgrass Prairie to the east and Short Grass
Prairie to the west. Although precipitation is typical of the semi-arid
Mixed Grass Prairie, the Sandhills are characterized by post-climax,
tallgrass species typical of a greater moisture regime (Oosting 1948;
Keeler, et al 1980). This is due primarily to the moisture penetration and
holding capacities of the soil, root structures, and photosynthetic
strategies of cool and warm season plants (Tolstead 1942; Barnes 1984).
The Refuge plant herbarium contains 223 species; however, the
collection is incomplete (Appendix F).
Vegetative Types
Four basic vegetative types or range sites are on the Refuge (NRCS
1995). (see Map 4)
Wetland Range Sites. These low meadow sites make up only 1 percent of
the Refuge and are dominated by species that thrive in a moisture-saturated
soil profile, such as prairie cordgrass, blue-joint reed grass,
sedge species, and non-grass species such as golden rod, dock, and
willows.
Sub-irrigated Range Sites. These are meadows close to the groundwater
level where soil moisture can support deep-rooted, warm season native
grasses even during drought. They make up about 9 percent of the
Refuge and are dominated by tallgrass species such as switchgrass and
sand bluestem. They are also prone to invasion by exotic species, such as
Kentucky bluegrass and smooth brome, and noxious weeds, such as
Canada thistle.
Sand Range Sites. These include the dry meadows (the edge between
wet meadows and the sandhills) and the gently undulating sandhills,
They make up about 76 percent of the Refuge. Predominate grasses
include both cool season species such as needle-and-thread and western
wheatgrass, and warm season species such as prairie sandreed, sand
bluestem, sand love grass, and sand dropseed. Common non-grass
species include prairie sunflower, yucca, lead plant, and prairie rose.
Exotic species, such as cheatgrass, will invade these sites.
Choppy Sand Range Sites. These are the characteristic dunes for which
the Nebraska Sandhills are named and make up about 11 percent of the
Refuge. They support a wide variety of vegetation but also contain
many, relatively small, unvegetated areas, commonly called “blowouts,”
that are subject to wind erosion. The number of blowouts vary with
terrain but, overall, these open sand areas make up about 3 percent of
the choppy sand range sites. Blowout penstemon (Penstemon haydenii),
a federally-listed endangered species, is endemic to the Sandhills and its
characteristic habitat includes the blowouts and open sand areas.
Predominate grasses include blue grama, sand bluestem, sand dropseed,
blowout grass, sand love grass, little bluestem, and sandhills muhly. Non-grass
species include yucca, sand cherry, prairie rose, and prairie
sunflower.
22 Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002
Figure 1. Penstemon Populations
Year Native Surviving
Transplants
Total
1987 2,058 -- 2,058
1988 1,652 -- 1,652
1989 1,264 -- 1,264
1990 1,545 -- 1,545
1991 765 -- 765
1992 1,055 -- 1,055
1993 985 -- 985
1994 956 -- 956
1995 624 -- 624
1996 608 -- 608
1997 533 332 865
1998 415 831* 1,246
1999 407 777** 1,184
2000 486 546*** 1,032
* Includes 1998 transplants
** Does not include the 1999 transplants
*** Does not include the 2000 transplants
Perennial and annual flowering forbs are an important component of true
native prairie and are more abundant on the Refuge than on the
surrounding private lands which are managed for livestock production.
Although formal surveys are not conducted, refuge managers have
observed an increase in non-grass species since grazing was reduced
starting in 1993.
There are about 45 species of native and introduced trees and shrubs in
the Sandhills, 30 of which occur on the Refuge. Some, such as sand sage,
choke cherry, sandbar willow, and cottonwood, are characteristic of
native prairie. Many are not. The Civilian Conservation Corps planted
native and nonnative trees and shrubs during the 1930s, most of which
have disappeared. Mature trees succumb to prairie fires and porcupines,
and seedlings rarely survive deer and rodent browsing. The only tree
species that has become successfully established without human
assistance is the green ash which reproduces well but only in the shade
canopy of mature willows or cottonwoods. There are about 80 acres of
trees on the Refuge.
Endangered Plants
Hayden’s, or blowout, penstemon is Nebraska’s rarest plant (Farrar
1990) and the only endangered plant on the Refuge. It was placed on the
Federal list of endangered species in 1987. This plant is somewhat unique
in that it depends on non-vegetated
sand surfaces, or
blowouts, for its existence (Fritz,
et al 1992). Good management of
private grazing lands has
reduced the amount of blowouts
in the Sandhills; only in the drier
western fringes are blowouts still
common. In 1984, The Nature
Conservancy purchased an 840-
acre area adjacent to the Refuge
specifically for perpetuation of
blowout penstemon.
Blowout penstemon surveys
began on the Refuge in 1987
when 2,058 plants were found. In
1998, only 415 remained (see
Figure 1). Although shrinking
habitat is part of the problem,
plant populations are declining
even in areas with what appears
to be good habitat. So, other
factors are at work. Perhaps
genetic viability is failing as
plants become increasingly
isolated from each other. Since
1997, the University of Nebraska
has supplied seedlings grown at a
facility in Lincoln. About 9,500
plants have been planted on the
Refuge through 2000; about 15
percent of the 1997 planting and
20 percent of the 1998 planting
survived.
Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002 23
Plant Species of Management Concern.
Plant Species of Management Concern listed by the U.S. Fish & Wildlife
Service or the State of Nebraska are presented in Appendix H. In
addition, there are several other plant species which will receive special
management emphasis on Crescent Lake Refuge for the reasons listed
below:
Canada thistle Widespread noxious weed
Cheatgrass brome Exotic, expanding range
Common reed Exotic, expanding range
Eastern cottonwood High wildlife values, native plant,
decreasing range
Blowout penstemon Federally-listed endangered species,
decreasing range
Wildlife
The Nebraska Sandhills are one of the few large native prairie areas in
the United States that have not been substantially converted to
farmland or otherwise modified. Thus, most of the plant and animal
species present when settlement began are still present today.
Surveys and census activities are limited by staffing and funding. Most
are broad-scale sampling, which works well for large numbers of highly
visible species but yields erratic and questionable results for species
which are less visible or occur in smaller numbers. Some intensive, more
sophisticated surveys have been discontinued because of insufficient
staff and questionable data. As a result, high quality, refuge-specific
information is not available for many species.
Endangered and Threatened Species
There are no federally-listed endangered wildlife which depend on the
Refuge in any significant way. Prairie falcons, least terns, and piping
plovers are occasionally seen during migrations but are considered
casual visitors. The ferruginous hawk is considered a sensitive species
but is an uncommon migrant. Black terns and loggerhead shrikes are also
sensitive species which nest on the Refuge. Recent informal surveys
revealed about 100 tern nests and 20 shrike nests.
The swift fox, an infrequent visitor, is a State-listed species for which
little information is available. One siting was made on the Refuge in 2000
and an increasing number of sightings are occurring north of the Refuge,
but no official data is available.
The yellow mud turtle is another Refuge species of special interest and
will be treated as a listed species for planning purposes. The Refuge
population is centered at Gimlet Lake and is estimated at 4,000 to 5,000.
A study by Earlham College, which includes the Refuge, provides good
information on the biology of the turtle (Iverson, Annual Study Reports).
24 Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002
Figure 2. Average Peak Waterfowl Populations by Species
During Fall Migration, 1985-95 (*Nests on the Refuge)
Species Average Peak No.
* Trumpeter swan
* Canada goose
* Mallard
* Gadwall
* Pintail
* Green-winged teal
* Blue-winged teal
* Cinnamon teal
* Wigeon
* Shoveler
* Redhead
Ring-necked duck
* Canvasback
* Lesser scaup
Common goldeneye
* Bufflehead
* Ruddy duck
Common merganser
29
1,050
4,860
4,960
1,370
1,400
730
30
3,075
4,140
4,232
4,950
3,660
3,840
3,000
5,520
3,420
600
Birds
Nebraska includes 413 species on its official bird list, 279 of which occur
on Crescent Lake Refuge (Appendix F).
Species of Special Interest. For the purposes of this plan, Wildlife
Species of Management Concern are those listed by the U.S. Fish &
Wildlife Service, the State of Nebraska, or Partners in Flight as
declining and in need of special attention. Comparing these lists with the
Refuge bird list indicates 25 such species occur on the Refuge sometime
during the year (Appendix H). Little is known about the status and
trends of most of these birds or how they are affected, positively or
negatively, by present habitat management.
Waterfowl. Thirty-two species use the Refuge during some portion of the
year and 15 species nest on the Refuge. Peak numbers during the fall
migration occur in October and averaged 13,100 over the last 10 years.
Peak numbers during the spring migration occur in April and averaged
12,600 over the same period. Table 1 shows average peak numbers by
species.
Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002 25
Although the Sandhills, as a whole, are the most important waterfowl
production area in the State, Crescent Lake is not considered a
waterfowl production refuge per se. Duck breeding pairs ranged from
548 to 1,450 since 1987, a period which included very dry and very wet
years on both the Refuge and on portions of the major breeding grounds
to the north. The number of ducklings hatched ranged from 1,000 to
3,500. Among dabbling ducks, blue-winged teal are the most common
nesters (62 percent), followed by mallards (33 percent), gadwalls (3
percent), pintails (1 percent), and shovelers (1 percent). For diving
ducks, ruddy ducks are the most common nesters (48 percent), followed
by redheads (43 percent) and canvasbacks (9 percent).
Predation on duck nests is a limiting factor. Bullsnakes, weasels,
raccoons, and skunks are the major predators. Without predator control,
nest success rates hover around 16 percent, the bottom end of the rate
needed for population maintenance. An intensive bullsnake removal
program during the 1980s resulted in nest success rates up to 50 percent
on a small sample area. However, because nest densities are relatively
low, the resulting small increase in numbers of ducks produced to flight
stage could not be justified, and the program was discontinued in 1994.
Extensive predator control has not occurred on the Refuge since then.
There are 98 Canada goose nesting tubs on the Refuge, about 60 percent
of which are used annually. Hatching success is around 80 percent and
between 200 and 250 goslings are raised to flight stage. Few geese nest
off the artificial structures.
Marsh and Water Birds. Eared grebes nest on Goose and Deer Lakes.
Numbers vary considerably from year-to-year, and during the last 10
years ranged from 446 adults and 290 nests to 1,194 adults and 656 nests.
There is a long-standing double-crested cormorant rookery on Goose
Lake, and cormorants pioneered onto Crane Lake in 1997. The number of
nests over the last 10 years averaged about 60.
Great blue herons nest in the Crane Lake rookery. The number of nests
in the last 4 years ranged from 43 to 127; production estimates range
from 94 to 125 young hatched.
Black-crowned night-herons have traditionally nested at Smith Lake but,
for unknown reasons, the colony moved to Goose Lake in 1997. The
number of nests in the last 10 years ranged from 3 to 11.
American bitterns were first surveyed in 1996 (a breeding male song
survey on Smith, Goose, Gimlet and Island Lakes). From 1996 to 1999,
the number of males ranged from 24 to 35.
A rail call survey was initiated in 1997 and yields only trend information.
Virginia rail calls went from 36 to 20 and sora rail calls from 6 to zero in
the period 1997 to 1999.
26 Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002
Figure 3. 1997-1999 Raptor Breeding Survey Results
Average Breeding Average No.
Species Pairs Young
Red-tailed hawk
Swainson’s hawk
Bald eagle
Great horned owl
Northern harrier
American kestrel
Barn owl (in nest
structures)
2
5
1
2
8
4
8
4 (est.)
8
2
3
Unknown
15
24
Shorebirds, Gulls, Terns, and Allied Species. Thirty-one shorebird
species, 7 gull species, and 5 tern species occur on the Refuge. Of these,
11 species nest on the Refuge (Appendix F). No formal surveys are
conducted. Peak numbers of all species seldom exceed 2,500 in spring and
1,000 in fall.
Raptors. The open grasslands of the Sandhills, interspersed with small
areas of trees, provide excellent habitat and food sources for raptors.
Twenty-seven species have been recorded on the Refuge. Figure 3
presents 1997 breeding survey results, an average year.
Non-migratory Birds. Prairie grouse, a significant component of the
Nebraska Sandhills, are declining throughout their range (Proceedings
Prairie Grouse Technical Conference 1998). Crescent Lake Refuge is also
seeing declines. Sharp-tailed grouse lek surveys from 1986 to 1997 show
active dancing grounds decreasing from 45 to 15 and dancing males
decreasing from 413 to 109. Refuge populations seemed to rebound in
1998 and 1999 when the number of dancing grounds averaged 32 and the
number of dancing males averaged 226. The causes for the decline and
the significance of the recent increases are not clear.
The Refuge is on the western edge of the range of the greater prairie
chicken. This species has not been present with regularity since the
1950s, and then numbers seldom exceeded 100. Reintroduction projects
in the 1970s and 1980s were unsuccessful. A single male was seen on the
Refuge in the spring of 2000, and five were heard during the lek counts.
Ring-necked pheasants, exotic but popular game birds, occur in
relatively small numbers. The average breeding population from 1987 to
1999 was 361.
Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002 27
Mammals
The Sandhills provide habitat for a variety mammals (Appendix F). Pre-settlement
mammalian fauna included 59 species. Ten carnivores and
ungulates were probably extirpated by 1900, including the bison, elk, and
bighorn sheep. Ten mammals have been introduced or their natural
ranges extended, including the fox squirrel, black-tailed jackrabbit, and
raccoon (Jones 1964).
White-tailed deer and mule deer are both present. The best populations
estimates are from the period 1979 to 1991 when aerial surveys were
conducted. Estimated average populations during that period were 110
mule deer and 152 white-tailed deer. Populations have not significantly
changed since that period, although aerial surveys are cost-prohibitive
and were replaced with less accurate ground surveys. The largest
harvests since the hunter check station was initiated in 1981 occurred in
1998 and 1999 when 66 and 47 deer were checked respectively. The
average harvest since 1981 is 32.
Because of their economic importance and because they can alter
wetland habitat, muskrats have been surveyed by counting houses in the
winter since the Refuge was established. Population peaks occurred in
1950 (934 houses), 1989 (1,929 houses), and 1996 (742 houses). During the
last peak, considerable opening of cattail marshes was noted.
Coyote scat counts were initiated in 1997 and supply population trends
which have been stable during the survey period. Estimates of
population numbers are not available.
There is no data for population trends of other mammal species.
Amphibians and Reptiles
The most common reptiles and amphibians are the box turtle, bullsnake,
tiger salamander, and garter snake (Appendix F). The yellow mud turtle
is considered a Refuge species of special interest and is discussed under
endangered species.
Fish
Fisheries have been managed by the NGPC under an agreement with
the Refuge since 1991, when FWS fisheries capabilities were reduced.
Island Lake has been open to sport fishing since 1931. Carp were
eliminated in 1978, and the lake now supports warm water species
including largemouth bass, bluegill, crappie, yellow perch, walleye, and
sauger. However, a few carp of even-age class were discovered in the
spring of 2000 and the problem may reemerge.
Carp were reduced, but not eliminated, in Smith Lake in 1996. That lake
now supports a perch/panfish fishery but may develop a serious carp
problem in the future. Crane Lake is the only other lake with sport
fishery potential and was stocked with yellow perch in 2000. The fathead
minnow, the only other fish species on the Refuge, was introduced into
several lakes in the late 1970s. The minnow provides a food source for a
variety of birds but also creates turbid water, an undesirable result.
28 Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002
Cultural Resources
Little formal archaeological work has been conducted within the
Nebraska Sandhills. Collections by avocational archaeologists indicate
the area has a long prehistoric record and that artifacts are widely
distributed; however, because of the unique nature of the Sandhills,
settlement and subsistence patterns are difficult to predict (Burgett and
Nickel 1999). No systematic surveys have been conducted on the Refuge,
and no known Native American sites exist.
Historic use of the Sandhills is better documented. Only a few fur trade
and ranching operations existed prior to the Federal government’s
decision to survey the region and make it available for homesteading in
1904. Nearly all early attempts at farming failed and homesteads were
aggregated into efficient and successful ranching operations. No farm or
ranch buildings remain on the Refuge but old dump sites are still
scattered across the area. Two Refuge buildings and two fire towers
built by the CCC and WPA in the 1930s are subject to conditions of
Federal laws protecting historic resources.
Public Use
Crescent Lake offers a variety of public use opportunities including
hunting, fishing, wildlife viewing, photography, hiking, and
environmental education (Map 5). Public trapping has been allowed on a
permit basis. About 7,000 to 9,000 people visited Crescent Lake in recent
years, a drop of over 30 percent from the 13,000 recorded in 1987.
Counting methods varied somewhat throughout the period and may be
the reason for this drop.
Most visitors engage in more than one activity but the primary reason
for visits in recent years can be categorized as follows:
Hunting 3%
Fishing 67%
Wildlife viewing and photography 28%
Education/Interpretation 2%
The Refuge is open to hunting for mule and white-tailed deer, prairie
grouse, and ring-necked pheasants. It is not open for waterfowl, other
migratory birds, or predators, such as coyotes. The 5-year average for
deer hunting is 200 visits; the average for upland game is 300 visits.
Some hunters hunt for both deer and upland game during the same visit.
Fishing on Island and Smith Lakes is the most popular use of the
Refuge. In recent years, fishing visits averaged about 5,000, of which 20
percent occurred during winter months. Supporting facilities are limited
to two graveled boat ramps and two fishing piers on Island Lake. Boats
are only allowed on Island Lake and gas powered engines are prohibited.
Formal education/interpretation facilities are limited to one auto tour
route along the County road and modest information kiosks and displays
at the headquarters. The Refuge is available as an outdoor classroom;
however, the isolated location, sparse local population, and distances to
schools limits use to about 200 students per year.
Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002 29
Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002 31
IV. Refuge Goals, Objectives,
and Strategies
Background
This is a 15-year plan, but only the goals will remain static. Objectives
and strategies are based on present knowledge and reflect known needs.
They may change, as may specific management actions, as knowledge
and needs change. Public involvement will be sought for any significant
amendments.
It is also important to understand that individual objectives cannot be
taken out of context. It is the mixture of objectives that will produce the
desired results. Generally speaking, on Crescent Lake Refuge, where
the legal mandate is to serve as a “refuge and breeding ground for birds
and other wild animals,” habitat is managed to support or produce birds
and other wildlife. However, because it is the habitat over which wildlife
managers have most control, a clear understanding must also occur of
the kinds and amounts of habitat needed to support that wildlife. Public
use and environmental education are also important functions of the
Refuge. Thus, it is important to know what kinds and how much public
use can be allowed and remain compatible with the wildlife purposes and
objectives.
Although ecological diversity is part of the Refuge vision, the Refuge is
limited in size and cannot be all things to all forms of wildlife. Therefore,
in order to decide how much of specific habitats are needed and how to
manage those habitats, it is necessary to define which animals or groups
of animals will receive priority and where. For instance, if a conflict
exists between providing for a species listed as ‘threatened” under the
Endangered Species Act and providing for mallard ducks, the threatened
species and its habitat may be given priority. Similarly, a species once
part of, but now missing from, the “refuge ecosystem” may be given
priority over a non-indigenous species or a species common on and off
the refuge. Once such decisions are made, the types and management of
habitat can be described.
The wildlife priorities for Crescent Lake Refuge are:
1. endangered or threatened species;
2. species considered candidates for listing as threatened or
endangered, and Species of Management Concern (species
which, based on scientific evidence, are or are becoming rare, or
are steadily declining in numbers, and for which proper habitat
occurs on the Refuge);
3. migratory birds;
4. species that are dependent upon some special quality of the
habitat found on the Refuge;
5. fish and wildlife that people use consumptively; and
6. organisms that, because of a unique quality, are of special
interest to people.
32 Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002
“That, apart from the members
of our own species, they (our
fellow creatures) are our only
companions . . . a perennial joy
and consolation.”
-William Morton Wheeler,
Scientist
Endangered, Threatened, and Candidate Species
Plants and animals listed as endangered or threatened by either the
Federal government or the State of Nebraska will receive priority in all
Refuge management decisions. Only two are known to use the Refuge in
any significant way (See Section III, Refuge and Resource Descriptions).
The federally-listed blowout penstemon, a plant which grows only on
sand soils in areas devoid of other vegetation; and the State-listed swift
fox. The Refuge is in the heart of the remaining penstemon habitat. The
swift fox is an infrequent and casual visitor but an increasing number of
sightings are being recorded in the vicinity, primarily just off the Refuge
to the north. A third species, the yellow mud turtle, is a sensitive species
and, as such, will also receive priority consideration.
Goal 1: Contribute to the preservation and restoration of endangered
flora and fauna that are or were endemic to the Crescent Lake
Refuge area.
Objective: Maintain five population groups of blowout penstemon with at
least 300 plants in each group (one half of the Recovery Plan goal).
Native plants declined from 2,050 in the first survey in 1987 to 608 in
1996 (see Figure 1). A transplant program was started in 1997 in
cooperation with the University of Nebraska. The penstemon survey
conducted in 2000 found 1,032 plants (not including plants transplanted
that spring). Although the number of plants on the Refuge has increased,
the survival rate of the transplants is low and the immediate future
seems to include a continuous input of hand-grown plants. It also appears
that habitat shrinkage is not the only reason for declining numbers.
There are many blowouts with suitable habitat where the plants
continue to decline. A large number of new blowouts were started in the
winter of 1997 but none were colonized by 1999. Transplants appear
more vigorous and it may be that native plants have become genetically
deficient from many years of isolation. Transplantation may result in
increased vigor over time.
Strategies:
■ Continue the transplant program; monitor population status,
survival rates, colonization, and other parameters to evaluate
and adjust management.
■ Prepare maps showing the past, present, and desired location of
penstemon populations on and nearby the Refuge, and overlay
information regarding numbers of plants, densities, transplants,
etc.
■ Protect existing penstemon populations on private lands
adjacent to the Refuge.
Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002 33
Objective: Attempt to verify swift fox use on the Refuge.
The Refuge is not considered prime swift fox habitat and the fox is a
casual visitor. Their primary range is west of the Refuge.
Strategies:
■ Investigate sightings and use scent stations to aid in verifying
presence of swift fox.
■ Conduct literature search to find ways that habitat may be
enhanced for swift fox.
Objective: Maintain present population numbers of 4,000 to 5,000 yellow
mud turtles and protect their habitat.
The yellow mud turtle is a Species of Management Concern due to low
numbers and isolated populations. It is found in only a few places in
Nebraska and Arizona. On the Refuge, it is found almost exclusively at
Gimlet Lake. Refuge population estimates range from 4,000 to 5,000.
These turtles migrate across the County road twice a year and are
especially vulnerable at those times. A long-term study by Dr. John
Iverson of Earlham College, Richmond, Indiana, has provided valuable
information regarding the biology of the turtle; however, information is
limited that provides specific guidance for preservation and management
of this species.
Strategies:
■ Continue to support the studies conducted by Earlham College
and seek information leading to specific management actions.
■ Seek ways to eliminate mortality on the County road during
migrations.
■ Consider yellow mud turtles in all habitat management decisions
for Gimlet Lake and their nesting and hibernating area north
and east of Gimlet lake during development of the Habitat
Management Plan.
34 Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002
When Henry David Thoreau
borrowed an axe from a neighbor
and set about building his cabin at
Walden Pond, he was determined to
“front only the essentials of life, and
see if (he) could not learn what it
had to teach . . . ”
Perhaps the overriding purpose of
these special places is to learn from
them what they have to teach.
Special Places
Wilderness
The Wilderness Act of 1964 (Public Law 88-577/16 U.S.C. 1131-1136)
defines wilderness as:
“A wilderness, in contrast with those areas where man and his
works dominate the landscape, is hereby recognized as an area
where the earth and its community of life are untrammeled by
man, where man himself is a visitor who does not remain. An
area of wilderness is further defined to mean in this Act an area
of undeveloped Federal land retaining its primeval character and
influence, without permanent improvements or human
habitation, which is protected and managed so as to preserve its
natural conditions and which (1) generally appears to have been
affected primarily by the forces of nature, with the imprint of
man’s work substantially unnoticeable; (2) has outstanding
opportunities for solitude or a primitive and unconfined type of
recreation; (3) has at least 5,000 acres of land or is of sufficient
sizes to make practicable its preservation and use in an
unimpaired condition; and (4) may also contain ecological,
geological, or other features of scientific, educational, scenic, or
historical value.”
In 1972, 24,502 acres of the Refuge were proposed for inclusion in the
National Wilderness Preservation System (see Map 2). Congress has not
acted on that proposal. In the intervening years, the area has been
managed to maintain and improve the wilderness characteristics that
existed at the time of the proposal. For instance, in 1972, there were 42
miles of fence, 39 windmills, and 44 miles of two-track trails within the
area. Today, there are 34 miles of fence and 30 windmills; and the two-track
trails have been closed and many have healed over.
Goal 2: Maintain and enhance the wilderness qualities of the proposed
Wilderness Area.
One of the objectives for the Refuge is to reintroduce bison into the
proposed Wilderness Area (see Fish and Wildlife Objectives). To do that
will require preparation of a bison management plan and a significant
increase in funding and staff; a process that could take years. In the
interim, the wildlife and habitat management objectives presented in
this Plan will apply to the proposed wilderness but the management
practices and tools used to implement those objectives will be
“minimized.” For instance, motorized vehicles will be used to access the
area for noxious weed control only when no other feasible alternatives
exist and the action is essential to maintain the grassland ecosystem (see
Appendix G).
A need exists for a grazing animal within the Wilderness Area because
prolonged rest will result in habitat degradation. Cattle have been used
for that purpose in the past. On the Refuge, bison (if approved for
reintroduction) would be free ranging and present seasonally or,
perhaps, year-round; they would become part of the landscape. Their
presence may change the appearance of habitats within the wilderness
but in ways that would make it more like the Sandhills Prairie that
existed pre-development.
Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002 35
The specific impacts of bison will be analyzed and presented in a bison
management plan. While bison would add to the natural diversity of the
Wilderness Area, they would be reintroduced only if compatible with the
other wilderness purposes.
Interim Objectives (without the presence of bison):
All wildlife and habitat management objectives in this Plan would apply
to the proposed Wilderness Area until the decision whether or not to
reintroduce bison is made.
Interim Strategies (without the presence of bison):
■ Prepare, by December 31, 2002, an interim wilderness
management plan that reevaluates the use of cattle grazing and
fire to maintain wilderness characteristics, and further defines
the use of “minimum tools.” This Plan would be rewritten to
reflect the presence of bison, should that event occur.
The present Upland Habitat Management Plan calls for
cattle grazing on a 20-year rotation on sands and choppy sands
range sites, and a 6-year rotation on the meadows. Prescribed
burning could possibly be substituted for cattle in the meadows.
The minimum use of other tools must be more clearly defined,
especially the use of motorized access for noxious weed control,
law enforcement, wildfire control, management for blowout
penstemon (an endangered species), and facilities maintenance.
Public use must also be reevaluated. See Appendix G for a
preliminary discussion of “minimum tools” and how they might
be applied.
■ Continue to remove all permanent fences and other livestock
facilities not essential to maintain the prairie ecosystem.
■ Establish monitoring systems to: evaluate the effects of
“minimum” management on wilderness characteristics (to be
defined in the interim wilderness management plan); and
compare habitat and wildlife use in the wilderness with
surrounding Refuge and private lands.
■ Seek from the NGPC concurrence for a special regulation which
will allow hunters to bone out deer in the field within the
proposed wilderness.
36 Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002
Research Natural Areas
Two Research Natural Areas were established in 1955 by a Director’s
Order and included on a National list of Research Areas (see Map 2). The
Goose Lake RNA is 904 acres and the Hackberry RNA is 172 acres. The
purposes of Research Natural Areas are: (1) to preserve examples of
undisturbed ecosystems for comparison with those influenced by man; (2)
to provide educational and research areas for scientists to study ecology,
successional trends, and other aspects of the natural environment; and
(3) to serve as gene pools and preserves for rare and endangered species
of plants and animals.
Both RNAs are treated as separate habitat units in the Upland
Management Plan (1996). These areas have been allowed to evolve
without interference. Habitat manipulation has been essentially non-existent.
Neither area has been grazed since 1955. A portion of the
meadow along Goose Lake was included in a prescribed burn in 1985. No
wildfires have occurred. Noxious weeds have been controlled since 1992
when Canada thistle invaded the meadows of both units. Both areas are
within the closed area of the Refuge, and public use has not been
allowed. Unfortunately, no significant research has occurred in either
area in part because of the remoteness of the Refuge. See the Upland
Habitat Plan for additional information.
Goal 3: Preserve plant and animal communities in a natural state for
research purposes.
Objective: Maintain 1,076 acres of the Research Natural Area in a
condition approaching grassland climax stages and affected only by
natural forces.
Strategies:
■ Initiate management practices only where necessary to preserve
vegetation and only as stated in a Natural Area Management
Plan (8 RM 10.8 F) or amend the 1996 Upland Management Plan
or address in a Habitat Management Plan.
■ Reduce total thistle acreage, and any other noxious plants that
appear, using integrated pest management techniques.
Eradication is not feasible but the plant should not be allowed to
spread or become the dominant species in a given area.
Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002 37
“In general, the trend of the evidence
indicates that in land, just as in the
human body, the symptoms may lie
in one organ and the cause in
another.”
- Aldo Leopold
(Sand County Almanac)
Upland Habitat
Goal 4: Preserve, restore, and enhance the ecological diversity of
indigenous flora and fauna of the physiographic region
described as the Sandhills Prairie.
An Upland Habitat Management Plan was approved for Crescent
Lake Refuge in 1996. Referred to as a “step-down plan,” it presents
specific habitat descriptions and management techniques that will
enhance and maintain the required habitat necessary to sustain
wildlife populations and achieve stated habitat objectives. The
following objectives are taken from that document.
The general theme of grassland or prairie management on Crescent
Lake Refuge is to maximize native warm season grasses and create a
general landscape that resembles “native” Sandhills Prairie throughout
the year. This is desirable because surrounding private lands have a
different purpose (primarily cattle production) and, thus, have less
residual cover available in the early spring for ground-nesting birds.
Cool season and exotic grasses (such as Kentucky bluegrass, smooth
brome, and cheatgrass) begin growing in early spring and reach maturity
(cure out) in mid-summer. By the following spring, they are mostly lying
flat and of little use to nesting birds. Native warm season grasses do not
begin to grow until early or mid-summer. They are generally bigger,
more robust, and remain standing throughout winter and spring. Many
bird species are adaptable and can survive in less than optimum habitat,
although their numbers are generally fewer. However, some species of
birds have specific habitat requirements and are decreasing throughout
their range or becoming rare because of changes in vegetation structure
and composition resulting from commercial uses. The Refuge can and
should provide habitats not common on surrounding private lands.
Five major habitat types occur on the Refuge. These include: Wetlands
(open water, seasonally flooded, and emergent vegetation 3,110 acres),
Subirrigated Meadows (4,195 acres), Sands (27,611 acres), Choppy Sand
(1,718 acres), and Sands/Choppy Sands (8,653 acres) mix (see Map 4).
These types are defined by a combination of soil type, slope, plant
composition, and moisture. Goals, objectives, and strategies will be
defined by habitat type. The Refuge also has two Research Natural
Areas and a proposed Wilderness Area requiring special management
strategies to achieve habitat and wildlife goals and objectives.
The following objectives are designed to result in a landscape simulating
native prairie habitat which will support a diversity of wildlife species.
These objectives apply to the entire Refuge, including the proposed
Wilderness Area (see Wilderness objectives). How these objectives are
achieved will be slightly different within the proposed Wilderness Area
because, there, the use of management tools must be minimized. The
Wilderness Area will be managed under an interim plan until a
Wilderness Management Plan is written.
Objective: Develop a vegetative map (in GIS format) that follows the
Nebraska Range Site description (NRCS 1995) or is consistent with
and/or is easily cross-walked to the NRCS system showing past, present,
and desired structure and composition by 2005.
Strategy:
■ Contract vegetative mapping to be stored in a GIS Arcview
system.
38 Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002
Subirrigated Meadow
Goal 5: Preserve, restore, and enhance the ecological diversity of
indigenous flora and fauna of the Subirrigated Meadow habitat
type.
Past and present management on subirrigated meadows encouraged
grass species which provide tall and dense residual cover (e.g. switch
grass, Indian grass, big bluestem). Prescribed fire and spring grazing
treatment using cattle were, in the past and are now, the primary tools.
When the desired landscape is achieved, use of these tools will be
minimized to allow maximum nest success. Nest site vegetative
structure has been determined for most Species of Management
Concern.
The emphasis will be placed on the following wildlife species of
management concern when managing for specific vegetation composition
and structure in the subirrigated meadow habitat type: eastern
meadowlark, prairie chicken, upland sandpiper, Swainson’s hawk, short-eared
owl, loggerhead shrike, northern harrier, bobolink, and dickcissel.
Wildlife species requiring the same habitat quality and type that will also
benefit, but not considered species of management concern as defined by
the Service, are American avocet, willet, Wilson’s phalarope, bobolink,
and waterfowl (primarily blue-winged teal, mallard, gadwall, pintail, and
shoveler).
Duck nesting preferences are well known. Refuge nest studies indicate
that upland nesting ducks generally prefer the tall, mature, dense cover
of the subirrigated meadows. The literature supports this general
conclusion (Duebbert 1966 and 1969; Duebbert and Lokemoen 1976;
Imler 1942, unpub. data; Bue 1952; Clark 1977; Gjersing 1975; and Kirsch
1978). Upland nesting ducks on the Refuge include the blue-winged teal
(62%), mallard (33%), gadwall (3%), pintail (1%), and shoveler (1%).
Although sharp-tailed grouse prefer the northeast slopes of sandhills,
they do require tall residual cover and will nest in the subirrigated
meadows. Prairie chickens have not nested on the Refuge since the early
1970s but, when present, relied almost totally on the subirrigated
meadow type for nest and brood habitat.
Objective: Maintain 90 to 100 percent native grass composition on 4,195
acres of subirrigated habitat to meet the needs of species of management
concern and associated species as outlined above. Plant composition will
consist of approximately 80 to 85 percent grass and sedges (big bluestem,
Indian grass, Canada wildrye, prairie cordgrass, slender wheatgrass,
prairie sandreed, prairie June grass, sand bluestem, switchgrass and
various sedges and rushes), 5 to 15 percent forbs, and less than 10
percent shrubs.
Strategy:
■ Develop management treatments using grazing and burning in a
Habitat Management Plan based on wildlife species priorities
and unit floristics as outlined in the Upland Management Plan.
Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002 39
Objective: Increase (by 5 to 10 percent) or maintain the warm season
grass component with native grass species, primarily Indian grass,
prairie cordgrass, prairie sandreed, switchgrass, sand and big bluestem,
and Canada wildrye, while reducing by 5 to 10 percent introduced cool
season grasses, Kentucky bluegrass and reed canary grass.
Strategy:
■ Utilize spring grazing and fall disturbance (grazing, burning) to
set-back cool season grasses and favor warm season grasses. (See
Upland Management Plan for details on timing and stocking rates.)
Objective: Maintain and/or increase residual nesting cover in the spring
by creating Visual Observation Reading (VORS) in the following
categories: (primarily for shorebirds, waterfowl, bobolinks, and eastern
meadow larks) <0.5 dm (~15 percent) (shorebirds), 0.5-1. dm (~ 20 percent)
(shorebirds), 1-1.5 dm (~15 percent) (waterfowl), 1.5-2 dm (~15 percent)
(waterfowl, eastern meadowlark, bobolink), 2-2.5 dm (~10 percent)
(waterfowl), >2.5 dm at least 15 percent (northern harrier and short-eared
owl). This information is based on Refuge data nest site vegetation
structure collected from 1997 to 2001.
Strategies:
■ Graze, burn, or hay no more than 40 percent of the subirrigated
meadow type in any one year.
■ Remove no more than 10 percent of warm season grass residual
cover in fall (late September - early October).
■ Utilize spring and fall disturbance to set-back cool season
grasses and favor warm season grasses.
Some passerine birds, for example western kingbird and orchard oriole,
are present on the Refuge only because of the existing tree cover.
Loggerhead shrikes and Swainson’s hawks (both Species of Management
Concern), great blue herons, and bald eagles are also dependent on trees.
Unless there is a demonstrated biological need for more of any species
dependent on this habitat, tree cover will be maintained at approximately
present amounts and locations. Resident species such as white-tailed
deer, mule deer, sharp-tailed grouse, and ring-necked pheasants are
dependent, to some degree, on the few trees on the Refuge.
Objective: Maintain tree cover at the present 80 acres with emphasis on
willow and cottonwood regeneration.
Strategies:
■ Mechanically remove Russian olive which have the potential for
rapid expansion.
■ Protect willow and cottonwood saplings near current aging
trees.
Objective: Reduce total acreage of Canada thistle infestation from the
approximate 800 acres (at present) to 350 acres by 2008 and continue
control measures in the future to prevent additional acreage infestation.
Strategy:
■ Manage Canada thistle using integrated pest management
techniques. Eradication is not feasible but the plant should not
be allowed to spread or become the dominant species in a given
area. Eradicate and/or control, by mechanical removal and spot
application of appropriate herbicides, other noxious plants as
they appear.
40 Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002
Sands, Choppy Sands, and Sands/Choppy Sands
Mixed Habitats
There are 3 habitat types of uplands on Crescent Lake Refuge based on
NRCS habitat typing. They are Sands (27,611 acres), Sandy (which is
combined with sands because there is only one small site on the Refuge),
and Choppy Sands (1,718 acres). There are also areas of mixed habitat
were the scale did not allow Sands and Choppy Sands to be delineated
(8,653 acres). In the mixed types, there are those considered
Sand/Choppy Sands Mix > 60 percent, Sands and Choppy Sands/Sands
Mix > 60 percent, and Choppy Sands. Based on vegetation, structure and
species composition these areas need to be separated for management
purposes to meet specific wildlife goals.
Goal 6: Preserve, restore, and enhance the ecological diversity of
indigenous flora and fauna of the Sands, Choppy Sands, and
Sands/Choppy Sands Mixed habitat types.
Undeveloped Sandhill Prairie supported a mixture of tall warm season
grasses, shorter cool season grasses, and a variety of forbs. Today, this
native mixture is not common on surrounding private rangeland.
However, these private lands do provide an abundance of short grasses
for wildlife which need short grass for all or a part of their life cycle.
While the original mosaic cannot be duplicated, by emphasizing warm
season grasses and forbs on the Refuge, a mixture of habitats can be
provided over a larger area.
Species which will benefit from taller vegetation include the grasshopper
sparrow, bobolink, and prairie chicken. Birds which may be disposed to
shorter grass surrounding the Refuge include killdeer, willet, horned
lark, and lark bunting (Kantrud 1982; Kirsch 1978; and Ryder 1980).
The year-round requirements of sharp-tailed grouse are met by the
mixture of grasses and forbs on the sands and choppy sands range sites.
They do show a preference for the northeast slopes of sandhills for
nesting, often adjacent to subirrigated meadows, although they will also
nest in the meadows.
Duebbert (1974) states “Residual nesting cover or dead vegetation
carried over from year-to-year is a very important component of nesting
cover. However, if the non-use period extends for too many years, the
vigor of the vegetation and its value as nesting cover eventually declines.
A system of vegetative management that includes several years of non-use
interrupted by nearly complete cover removal during one year
appears to maintain good nesting.”
The desired vegetation and wildlife use on these two range sites is
encouraged by a combination of fire, grazing, and rest. Management will
strive for a balance between providing undisturbed wildlife cover and
maintaining vegetative composition and structure to benefit primarily
grasshopper sparrows, western meadowlarks, sharp-tailed grouse,
mourning doves, vesper sparrows, and lark sparrows.
Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002 41
Objective: Maintain 90 to 100 percent native grass composition on Sands
(27,611 acres), Choppy Sands (1,718 acres), and Sands/Choppy sands
(8,653 acres) mixed habitat types to meet the needs of species of
management concern and associated species as outlined above. Plant
composition will consist of approximately 80 to 85 percent grass and
sedges; (blue and hairy grama grass, sand lovegrass, needle-and-thread,
sand dropseed, prairie sandreed, prairie June grass, sand bluestem,
switchgrass) and 5 to 10 percent forbs.
Strategies:
■ Develop management treatments using grazing and burning in a
Habitat Management Plan based on wildlife species priorities
and unit floristics as outlined in the Upland Management Plan.
■ Implement spring grazing and fall vegetation disturbance to set-back
cool season grasses and favor warm season grasses. (See
current Upland Management Plan for details on timing and
stocking rates.)
Objective: Increase the warm season grass component of the Sand and
Choppy Sands range types by 10 percent; emphasize sand bluestem in
sand range sites and sand bluestem, sand dropseed, and sand lovegrass
in choppy sands range sites.
Strategies:
■ Utilize spring and fall disturbance to set-back cool season
grasses and favor warm season grasses. (See current Upland
Management Plan for details on timing and stocking rates.)
■ Conduct one prescribed burn on a Sand or Choppy Sand range
site each year as a test to determine the effects of burning on
habitat and wildlife use and the effects of fire on creation and
maintenance of blowout penstemon habitat.
■ Do not graze/burn/hay more than 40 percent of the Sands habitat
type in any one year.
■ Do not remove more than 10 percent of warm season grass
residual cover in the fall.
■ Utilize inter-seeding of sand bluestem, prairie sandreed, and
switchgrass in pockets to develop higher VOR areas for nesting,
thermal, and escape cover.
Objective: Maintain quality nesting cover by providing residual cover in
spring. Develop spring VORS in the 0.5-1. 5 dm (grasshopper sparrow)
and 1.5-2.5 dm (upland sandpiper, long billed curlew, sharp-tailed grouse)
ranges on 40 percent and 20 percent of VOR readings respectively.
(Based on nest site vegetation structure data from Refuge records
collected 1997-2000.)
Strategies:
■ Do not graze/burn/hay more than 40 percent of the Sands,
Sands/Choppy type any one year.
■ Do not remove more than 10 percent of warm season grass cover
in fall (late September - early October).
■ Utilize spring and fall disturbance to set-back cool season
grasses and favor warm season grasses. (See current Upland
Management Plan for details on timing and stocking rates.)
■ Utilize inter-seeding of sand bluestem, prairie sandreed and
switchgrass in pockets, to develop higher VOR areas for nesting,
thermal, and escape cover.
42 Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002
Choppy Sands and Sands/Choppy Sands Mix
Choppy Sands site have been separated from Sands site because they
provide unique habitat for Refuge species. Blowout penstemon occurs in
this habitat were blowouts are more likely to occur. Lark sparrow also
only nest in this habitat type on the Refuge because the habitat type
meets the open requirements of this grassland nester.
Goal 7: Preserve, restore, and enhance the ecological diversity of
indigenous flora and fauna of the Choppy and Sands/Choppy
Sands mix habitat types.
Historically, the Sandhills had large amounts of blowouts and bare sand
runs. Possibly more than 50 percent may have been open sand. Blowout
penstemon was common. Historical fire intervals were 3 to 5 years, with
spring and fall wildfires. Species of Management Concern and associated
species include: lark sparrow, sharp-tailed grouse, mourning dove,
western meadowlark, vesper sparrow, grasshopper sparrow, upland
sandpiper, long-billed curlew, and blowout penstemon.
Objective: Create and maintain blowouts in five habitat units to maintain
blowout penstemon populations.
Strategies:
■ Reduce cover by frequent disturbance to expose sand to wind,
primarily through fall grazing.
■ Use mechanical means to create new blowouts in areas where
blowouts have healed.
■ Disturb designated areas on an average of every 3 to 4 years
with some variation in time and intensity of grazing.
■ Protect plants from grazing in May and early June.
■ Plant seedlings provided by the University of Nebraska, Lincoln.
Objective: Maintain 90 to 100 percent native grass composition on
Choppy Sands (1,718 acres) and Sands/Choppy Sands (8,653 acres) mix
habitat types to meet the needs of Species of Management Concern and
associated species as outlined above. Plant composition will consist of
approximately 90 to 95 percent grass and sedges (sandhills muhly, blue
and hairy grama grass, sand lovegrass, needle-and-thread, sand
dropseed, blowout grass, prairie sandreed, prairie June grass, sand
bluestem, switchgrass) and 5 to 10 percent forbs.
Strategies:
■ Develop species priority for each habitat unit and develop
grazing and burning treatments within the Habitat Management
Plan based on individual unit floristics (identified in the 1996
Upland Management Plan).
■ Implement spring and fall grazing and prescribe burning
programs with different durations of rest, depending on units
and wildlife uses, to set-back cool season grasses and stimulate
warm season grasses.
■ Maintain 20 to 40 percent bare ground, or less than 60 percent
litter cover, using rest rotation grazing cycles every 3 to 4 years.
Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002 43
Objective: Maintain quality nesting cover by providing residual cover in
spring. Develop spring VORS in the 0.5-1.5 dm (to meet open
requirements of some species) and 1.5-2.5 dm (lark sparrow, sharp-tailed
grouse) ranges on 40 percent and 20 percent of VOR readings
respectively.
Strategies:
■ Do not graze/burn/hay more than 40 percent of the Choppy and
Sands/Choppy Sands mix types in any one year.
■ Do not remove more than 10 percent of warm season grass
residual cover in the fall.
■ Utilize spring and fall disturbance to set-back cool season
grasses and favor warm season grasses. (See current Upland
Management Plan for details on timing and stocking rates.)
Wilderness - Special considerations to above habitat
goals, objectives, and strategies
Goal 8: Preserve, restore, and enhance the ecological diversity of
indigenous flora and fauna of the physiographic region
described as the Sandhills Prairie, while maintaining and
enhancing the wilderness quality.
Objective: Maintain the integrity of the 24,502-acre proposed Wilderness
Area as intended by Congress in the Wilderness Act of 1964, Service
policy, and Director’s Order #116, Wilderness Stewardship Training.
Strategy:
■ Utilize bison and, where possible, prescribed fire as a “natural”
disturbance to meet above habitat goals, objectives, and
strategies.
The Refuge staff believes that neither the wilderness characteristics nor
the established wildlife goals can be met without the use of grazing and
fire.
44 Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002
Wetland Habitat
Wetlands (lakes and marshes) constitute about 18 percent of the total
Refuge. Most wetlands are shallow and dependent on annual
precipitation; only nine lakes have any potential for water level
manipulation. The overriding concern is the gradual filling of wetlands by
emergent vegetation, windblown sand, and decaying plant material until
they eventually become dry land. This process is particularly important
because the Sandhills Prairie is a managed area and becoming more
stable and less subject to natural forces. Wetlands were formed during
periods of prolonged drought by wind cut depressions occurring in the
Sandhills landscape. As water tables were restored, wetlands appeared
and vegetation stabilized the surrounding areas forming permanent
wetland depressions. Wetlands are no longer being created naturally and
probably will not be until the next prolonged drought, if then.
Management emphasis will be placed on the following species: waterfowl,
white-faced ibis, American bitterns, Virginia rails, red-winged and
yellow-headed blackbirds, marsh wrens, black and Forster’s terns, black-crowned
night-herons, and the yellow mud turtle.
Goal 9: Maintain natural and artificially managed permanent and
semipermanent wetlands to provide habitat for migratory
waterfowl, shorebirds, wading birds, and associated wetland-dependent
species.
Natural Lakes
There are 15 named lakes on the Refuge and more than 100 ponds of
varying sizes that provide a wide range of habitats for wildlife. Each
lake/wetland contains specific morphological, physiological, and biological
characteristics that combine to determine the ability to support and
maintain certain species of vegetation as a food source for migrating
waterfowl, shorebirds, and marsh related species and as an important
substrate for invertebrate resources. Natural functions are allowed to
dominate these bodies of water, but can be augmented to meet specific
wildlife goals or needs.
Objective: Maintain and/or augment the quality of the wetland habitat
(submergent and emergent vegetation and invertebrate levels) for
breeding and migrating birds as well as resident wildlife populations.
Strategies:
■ Allow for a natural cycling (wet and dry cycles) to occur as a
means to maintain necessary nutrient levels (e.g. plant and
animal detritus) to support targeted wildlife species.
■ Utilize prescribed fire and grazing on shorelines and emergent
vegetation.
■ Utilize pumping of lakes to eliminate the carp and allow for
stabilization of lake bottoms and annual vegetation
encroachment on occasion.
Objective: Prevent phragmites from occupying more than 15 percent of
any wetland basin.
Strategy:
■ Treat 100 percent of the phragmites areas with Rodeo (chemical
treatment) where possible.
Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002 45
Objective: Treat other invasive wetland plants if they appear on the
Refuge.
Strategy:
■ Conduct annual surveys to detect the presence of any exotic
wetland plant; coordinate with landowners and local County and
State officials to monitor the presence or expansion of purple
loosestrife on adjacent private lands.
Artificially Managed Lakes
The following lakes (wetlands) are artificially managed to provide the
habitat requirements necessary for the above listed wetland-dependent
species: Martin, Ramalli Marsh, Smith, Perrin, Redhead, Upper
Harrison, Gimlet, West Jones, and Duck Slough. Each lake/wetland
contains specific morphological, physiological, and biological
characteristics that combine to determine the ability to support and
maintain certain species of vegetation as a food source for migrating
waterfowl, shorebirds, and marsh related species and as an important
substrate for invertebrate resources. Specific resource management
information and recommended management direction for these lakes and
the following objectives are based on information found in Fredrickson
(2001).
Water management involves water level manipulation of the lakes,
limited dewatering of lakes without inflow or outflow by pumping,
flowage ditches, and water control structures.
Since the 1930s, the natural lakes along the Moore Valley drainage have
been equipped with water control structures and/or had small dikes
constructed to increase levels and allow for manipulation of water.
However, it appears that only Smith and Martin Lakes outlets were
utilized prior to 1958. Also, because most of these lakes are closed
drainages and permanent types of water, stagnation occurs. To remedy
this, pumping for drawdown began in about 1972.
Applications for State water rights have not been filed on these lakes
because Nebraska law does not allow for protection of “natural” lakes.
No records exist documenting the natural elevations and the amount of
additional water impounded above the natural levels.
The only Refuge water right of record is Permit No. A-16382 for 13 cfs
from Eldred Lake. The lake (currently a hay meadow) is located on
private lands and covered under a perpetual easement, permitting
diversion of water to the Refuge via the Eldred Diversion Ditch.
Consumptive water use has not be quantified.
46 Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002
Objective: Provide vegetative composition (sago pondweed,
softstem/hardstem bulrush, spikerush, Cypersus) and structure (tall
emergents) as a food source, and invertebrate substrate, for waterfowl,
shorebirds, and marsh-dependent bird species during spring and fall
migration and summer nesting to meet the necessary life requirements
as described in the Wetland Management Plan and/or the Habitat
Management Plan (to be developed).
Strategy:
■ Develop a Wetland Management Plan or Habitat Management
Plan incorporating the following strategies.
✓ Define each lake’s best wildlife use and potential and the
habitat necessary to meet the life requirements needed for
targeted wildlife species.
✓ Utilize complete drawdowns for 1 to 2 growing seasons to
recharge the nutrient cycle.
✓ Utilize partial drawdowns during a single year to provide
foraging habitats, with some variation in season, length, and
amount of drawdown defined by wildlife needs.
✓ Utilize high water levels, grazing and prescribe fire to
control vegetation, with some variation in season, and
length.
✓ Implement complete drawdowns on no more than two lakes
in a given year.
✓ Utilize complete drawdowns and Rotenone application to
eliminate carp.
✓ Utilize prescribed fire and grazing on shorelines and
emergent vegetation.
✓ Treat cattail edges to maintain “soft” edge for waterfowl
nesting.
✓ Maintain the existing database of surface and groundwater
resources. A record of surface and groundwater levels has
been maintained almost from the establishment of the
Refuge. It is essential that this record continue in order to
detect vegetation and other biological changes due to
changes in water levels and document wildlife use of these
habitats.
Objective: Prevent phragmites from occupying more than 15 percent of
any wetland basin. Phragmites are firmly established in the Refuge
wetlands and are invading adjacent vegetative types. It is estimated that
phragmites occupies about 2 percent of the wetland area. Total
eradication is not feasible.
Strategy:
■ Treat 100 percent of the phragmites areas with Rodeo (chemical
treatment) where possible.
Objective: Treat other invasive wetland plants if they appear on the
Refuge. Purple loosestrife, a particularly aggressive exotic plant, is
found within 100 miles of the Refuge on private lands.
Strategy:
■ Conduct annual surveys to detect the presence of any exotic
wetland plant; coordinate with landowners and local County and
State officials to monitor the presence or expansion of purple
loosestrife on adjacent private lands.
Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002 47
“What is man without the beasts? If
all the beasts were gone, men would
die from a great loneliness of spirit,
for whatever happens to the beasts
also happens to man.”
- Sealth, American Indian
Fish and Wildlife
Wildlife objectives, particularly those for migratory species, must be
considered in the light of: Continental and Statewide populations and
trends; the role of Crescent Lake Refuge; the potential of the Refuge
to make a measurable contribution at reasonable cost; and the effect
of applied management on other species. For instance, if a migratory
species, or group of species, is declining because of problems on
wintering grounds to the south, it does not automatically follow that
this Refuge should make significant adjustments in management to
produce or sustain more - but neither should that possibility be ignored.
Or, for example, if increases are indicated, care should be taken that
Refuge management is resulting in a net increase, not simply
redistributing animals from surrounding areas.
Goal 10: Preserve, restore, and enhance the ecological diversity and
abundance of migratory birds and other indigenous fish and
wildlife with emphasis on grassland-dependent species.
Waterfowl
Objective: Strive to maintain a 10-year average of 15 to 20 percent
Mayfield nest success in the subirrigated meadow (4,195 acres) habitat
type.
Historically, between 1,000 and 3,500 ducks are hatched per year, and 80
to 100 resident Canada geese nests result in 175 to 250 goslings hatched
per year. As stated before, Crescent Lake Refuge is not considered a
waterfowl production refuge. The Refuge’s overall contribution to the
recruitment of waterfowl to the Central Flyway is considered minimal.
Heavy predation by bullsnakes, weasels, coyote, skunks, and raccoons
limit production of the waterfowl and, it is assumed, other upland nesting
species. In the past, extraordinary efforts, such as snake fences and traps
which were tended every day during the nesting season, resulted in
significant increases in duck production. A 7-year average of 34.7 percent
Mayfield hatch success was observed within a snake exclosure as
opposed to 17.9 percent during the same period outside the exclosure.
However, the effort required to maintain the fence was extraordinary
and non-target species were being killed and injured in the fences. Such
effort is questionable, especially when duck populations are at high levels
throughout the Flyway.
Strategies:
■ Achieve and maintain an interspersion and diversity of
successional grassland stages as outlined in the Upland Habitat
section.
■ Utilize grazing (intensity, season, and duration) and prescribed
burning as management tools to achieve the habitat objectives as
outlined in the Upland Habitat section.
Objective: Provide nesting and brood-rearing habitat, primarily in the
artificially managed lakes/wetlands, for over-water nesting ducks
(redhead, canvasback, and ruddy).
Strategy:
■ Develop and implement a long-term Wetland Management Plan,
with goals, objectives, and strategies from Wetland section of
this Plan.
48 Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002
Objective: Provide quality feeding areas (abundant aquatic seed and
invertebrate production), on 5 to 7 lakes where water control is possible,
for spring and fall migrating waterfowl.
Strategies:
■ Develop and implement a long-term Wetland Management Plan,
with goals, objectives, and strategies from Wetland section, to
provide quality feeding habitat.
■ Provide spring feeding areas from late March through mid-May.
■ Provide fall feeding areas from late August through early
November.
Ground-nesting Grassland Passerines, Owls, Harriers,
and Shorebirds
Of the 15 common ground-nesting passerines, owls, harriers, and
shorebirds on the Refuge, nine are USFWS Region 6 Species of
Management Concern. Loss or alteration of large expanses of grassland
has made these species vulnerable.
Objective: Maintain and enhance breeding populations of ground-nesting
grassland passerines, by achieving apparent nest success of at least 40
percent and/or the following average singing males/station: Choppy
Sands and Sands/Choppy Sands mix sites - lark sparrow (2-2.5),
grasshopper sparrow (0.5-1), Sands sites - grasshopper sparrow (7-9),
long-billed curlew (0.1-0.5 ), upland sandpiper (0.1-0.5), Subirrigated
Meadow sites - eastern meadowlark (1-1.5), bobolink (0.1-0.5), upland
sandpiper (0.1-0.5), dickcissel (0.25-0.5).
Less work has been done with these species than the water-dependent
species, but it is known that some, such as the long-billed curlew, prefer
the shorter grass on the more heavily grazed areas which are common
outside the Refuge (Bicak 1977; staff observations). Therefore,
management designed specifically to increase such species on the Refuge
may not be necessary.
However, some species are more dependent on the habitats on the
Refuge. For example, a study of upland sandpiper preferences in the
area of the Refuge indicated that undisturbed cover was preferred for
breeding territories (Bandy 1980). Similarly, a study of habitat selection
by grasshopper sparrows in Garden County Nebraska (Hopton 1996)
indicated that ungrazed habitat had significantly higher populations.
Therefore, more information is needed to determine how habitat
management helps or hinders each species of concern and whether the
Refuge has significant potential to produce or support more.
Strategies:
■ Implement goals, objectives, and strategies from Upland Habitat
section to provide quality breeding, nesting, and fledgling habitat.
■ Devise and implement monitoring techniques to determine
status, trends and effects of management on land-based Species
of Management Concern.
■ Increase emphasis on and knowledge of non-waterfowl species;
devise and implement additional surveys and monitoring to
determine population status/trends and effects of management
on all Species of Management Concern.
■ Develop a species richness/diversity index to establish baseline
levels and measure population trends; this would apply to
wildlife in general.
Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002 49
Objective: Provide quality feeding areas (abundant aquatic seed and
invertebrate production), of exposed mud flats on 1 to 3 lakes a year
where water control is possible, for spring and fall migrating shorebirds.
Strategy:
■ Develop and implement a long-term Wetland Management Plan,
with goals, objectives, and strategies from Wetland section of
this Plan to provide quality feeding habitat.
■ Provide spring feeding areas from late April through early June.
■ Provide fall feeding areas from late August through early October.
Objective: Maintain breeding populations of 8 to 10 pairs of northern
harriers and provide habitat for 2 to 3 pairs of short-eared owls.
Strategy:
■ Implement goals, objectives, and strategies from Upland Habitat
section to provide quality breeding, nesting, and fledgling habitat.
Marsh Birds and Terns
Objective: Maintain present breeding populations and production of
indigenous, water-dependent Region 6 Species of Management Concern
including: American bittern, white-faced ibis, black rail, and black terns.
Objective: Maintain the habitat for nesting black and Forester’s terns at
Martin, Smith, Shafer, and Deer Lakes.
Objective: Maintain the habitat for nesting colonies of black-crowned
night-heron and white-faced ibis on Smith and Goose lakes.
Objective: Maintain breeding populations of American bittern (.5-1),
Virginia rail (.75-1.5), red-winged blackbird (3.5-5), yellow-headed
blackbird (1-3), and marsh wren (2-4) based on average singing males
found on the Refuge 30 station Call/Playback Survey.
Strategy:
■ The above objectives will be addressed by developing and
implementing a long-term Wetland Management Plan and
incorporating the habitat goals, objectives, and strategies from
wetland section of the CCP.
Objective: Maintain a great blue heron rookery with a target of 50 to 60
nests on Island and Crane lakes.
Strategy:
■ Maintain tree groves at Island and Crane lakes by protecting
existing trees from fire and grazing and preserving natural
regeneration.
Tree Nesting Species of Management Concern
Objective: Maintain habitat for a nesting population of 3 to 5 pairs of
Swainson’s hawk and the loggerhead shrike. Both the Swainson’s hawk
and loggerhead shrike are USFWS Region 6 Species of Management
Concern. Their preferred habitat is large expanses of grass for feeding
with occasional trees for nesting.
Strategy:
■ Maintain isolated trees throughout the Refuge by planting
individual trees near current trees as replacements.
50 Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002
Prairie Grouse
Objective: Establish and sustain two leks of prairie chickens (8 to 12
dancing males) on the Refuge.
The prairie chicken is now a rare nester on Crescent Lake Refuge and a
Refuge Species of Special Interest. The Refuge is on the edge of
historical prairie chicken range, and Refuge records indicate that
numbers never exceeded 100. A “trap-and-release” program conducted
from 1984 to 1986 moved 275 birds onto the Refuge; all had disappeared
by 1989. During the 2000 prairie grouse lek survey, a lek of 5 to 10 males
was confirmed within 1/4 mile of the east boundary near Big Soddy.
In the past, prairie chickens on the Refuge used primarily subirrigated
meadows for nest and brood habitat. The literature indicates that
residual cover is particularly important (Kirsch 1973; Schwartz 1945;
Jones 1963; Yeatter 1963; Christisen 1969; Lehman 1963; and Vichmeyer
1941). It also appears that the best prairie chicken habitat is vegetation
in an early successional, sub-climax stage; this is supported by an
apparent close relationship between prairie chicken success and the
frequency of fire.
Although nesting requirements for prairie chickens are similar to those
of some ducks (see Upland Habitat Objectives), more consideration must
be given to seasonal feeding requirements, roosting habitat, and the use
of management tools. Kirsch and Kruse (1973) found an increase in fruit
and seed production and plant variety on burned areas. It is possible that
annual requirements for prairie chickens cannot be met on the Refuge
without substantial changes in upland habitat management which may or
may not be compatible with management for other species. It is also
possible that special management areas would have to be set up to
sustain nesting populations.
Strategies:
■ By June 2003, determine the feasibility of reestablishing prairie
chickens.
■ If determined feasible, transplant prairie chickens at potential
sites in Red Kate and Lower East Jones meadows.
■ Develop and/or amend the Habitat Management Plan to reflect
the goals, objectives, and strategies in the Habitat section of this
Plan.
Prairie Chicken © Cindie Brunner
Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002 51
Objective: Maintain or enhance sharp-tailed grouse densities at a 10-year
average of 220 to 250 males on dancing grounds.
In 1998, the Refuge population was 235 dancing males, significantly
lower than the average of 380 in the late 1980s. An analysis of State
survey data indicates that a similar decline occurred throughout western
Nebraska, so the decline is not Refuge-specific. Although, specific causes
of the general decline are unknown, prolonged bad weather during the
nesting season and a high period in the cycle for predator populations are
possibilities.
Strategies:
■ Conduct an annual lek survey to determine population trends.
■ Develop and augment the Habitat Management Plan to reflect
goals, objectives, and strategies in the Habitat section of this
Plan.
■ Participate with the State in area-wide management strategies.
Objective: Strive to achieve a harvest ratio equal to or greater than 2.0
juveniles per adult based on the Refuge average harvest during stable
and growing population periods.
Strategies:
■ Obtain funding for a study on nest and brood rearing success.
■ Develop and augment the Habitat Management Plan to reflect
goals, objectives, and strategies in the Habitat section of this
Plan.
Objective: Provide habitat for representative numbers of other
migratory birds.
As stated earlier, species or groups of species are given some relative
priorities. Migratory species that have not been identified as having
some management concern are lower priority in the act of balancing the
habitat for the greatest diversity. The Refuge lacks information to
determine if management for higher priority species is to the detriment
of others.
Strategy:
■ Develop specific methods for monitoring population trends and
determining the effects of habitat management on individual
species or groups of species.
52 Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002
Mammals, Reptiles, Amphibians, Invertebrates, and Fish
Deer
Objective: Maintain healthy deer population (300 to 400) through habitat
management, population monitoring, and, if needed, harvest regulation
at the Refuge level.
Deer are an important attraction because most private lands in the
Sandhills are closed to public entry. Therefore, the Refuge should
provide viewing opportunities. Providing such management is
compatible with the needs of Federal trust species.
Both mule deer and white-tailed deer are very mobile and move on and
off the Refuge. Thus, Refuge populations vary from year-to-year and
season-to-season. Mule deer with identifiable characteristics often seen
on the Refuge have also been seen 15 miles southwest of the Refuge.
Harvest surveys have been conducted for years, however, by
themselves, yield questionable results. Available information suggests
that the population is not being over exploited because a substantial
number of older deer are being harvested.
Strategies:
■ Evaluate the reliability and usefulness of present surveys.
■ Develop and augment the Habitat Management Plan to reflect
goals, objectives, and strategies in the Habitat section of this
Plan.
■ Cooperate with the State in area-wide management strategies
and annual evaluations of Refuge hunting regulations.
Mammals, Reptiles, Amphibians, and Invertebrates
Objective: Ensure the diversity and abundance of indigenous mammals,
reptiles, amphibians, and invertebrate populations remain intact through
habitat manipulation.
Little is known about the status and trends of these other species; thus,
problems and needs may simply be unknown. Scientifically based,
defendable surveys and research are very time consuming and often
expensive, and past and present funding has limited such activity.
Caution must be exercised because poorly designed, erratic surveys can
yield misleading information. Crescent Lake Refuge is in a remote
location and it is difficult to attract long-term research or volunteers on a
sustainable basis.
Strategies:
■ Continue to seek more information on habitat requirements and
effects of management on reptiles, amphibians, fish,
invertebrates, and mammals.
■ Develop and augment the Habitat Management Plan to reflect
goals, objectives, and strategies in the Upland and Wetland
Habitat sections of this Plan.
■ Establish average densities of key indicator species to document
baseline levels and determine population trends.
■ Continue to seek alternative ways to obtain missing information
using valid, scientific methods (e.g., university studies, graduate
level research, volunteer assistance for surveys and census).
■ Seek funding for a permanent, full-time biologist and seasonal
support staff.
Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002 53
Fish
Objective: Maintain fish populations to provide a food source for fish
eating bird species and sport fisheries, when deemed compatible.
The Nebraska Game and Parks Commission manages sport fisheries on
the Refuge with the concurrence of the refuge manager, an arrangement
that has been valuable to both agencies. At present, Island, Smith,
Crane, and Blue Lakes have sport fisheries. Island, Crane, and Smith
Lakes have a variety of warm water species and are open to fishing.
Only the corner of Blue Lake is within the Refuge; the remainder is on
private land and not accessible to the public.
Carp are present in several lakes connected by a ditch in the Moore
Valley, West Jones Lake and in Island Lake. Populations can be
controlled by periodic drawdowns in those lakes where such control
exists, including the three lakes with sport fisheries.
Strategies:
■ Maintain management agreements with NGPC for Refuge sport
fisheries, for NGPC monitoring Refuge fish populations, and
stocking recommendations with the Refuge staff making the
final management decisions.
■ Write and implement long-term Wetland Management Plan with
goals, objectives, and strategies coming from the Wetland
section of this Plan.
■ Monitor carp populations and reduce and/or eliminate them
though drawdowns or pumping and pesticide treatments when
water quality does not support good invertebrate populations
and/or submergent vegetation.
■ Maintain year-round sport fishery at Island Lake. Maintain
winter fishing only on Smith and Crane lakes to minimize
disturbance to wildlife.
■ Evaluate any restocking of Smith Lake when carp control is
needed.
■ Evaluate any restocking of Crane Lake when the lake winter-kills.
Crane Lake historically has experienced winter-kills about
every 4 to 5 years.
■ Have NGPC continue to sample and monitor Island Lake for
increases in the carp population; initiate control if necessary to
protect the sport fishery.
■ Conduct literature search and or studies to evaluate management
and habitat needs of fish eating birds to provide for their needs.
54 Crescent Lake National Wildlife Refuge Draft Comprehensive Conservation Plan - March 2002
“Of what use are wild areas destitute
of their distinctive faunas?”
- Aldo Leopold
(Sand County Almanac)
Dale Henry
Bison
Objective: Reintroduce bison into the 24,502-acre proposed Wilderness
Area as part of an ecosystem that mimics the prairie ecosystem as it
functioned before changes brought on by development.
Grazing and fire were the major factors, together with soil and climate,
that interacted to make the Sandhill prairies what they were before
commercial grazing and other development arrived on the scene. The
grazing part of that equation was fulfilled largely by bison. Today, cattle
have replaced bison and fire is infrequent and rigorously controlled.
Wilderness, on the other hand, is an idea - a concept. One envisions a
“natural” area, affected only by natural forces and free from modern
human influences. In the case of the proposed Crescent Lake Wilderness
Area, the natural part of that vision, the wilderness characteristics
themselves, cannot be maintained over time without the forces that
created them in the first place. Two of those forces, fire and grazing, are
now tightly controlled. A need exists for a grazing animal in the proposed
Wilderness Area and cattle, a “man-made” influence, have served that
purpose in recent years - but so could bison.
The bison is the native ungulate missing from the equation. Free-ranging
bison could serve as both an agent for change and an addition to biotic
and aesthetic diversity. The presence of bison would contribute
significantly to the legal purpose, the vision and the goals of Crescent
Lake National Wildlife Refuge.
The Concept: Cattle have been used as a tool to help create and/or
maintain specific grassland scenarios (see Habitat Objectives). They are
allowed to graze for short periods of time under controlled conditions and
only when necess