Crescent Lake Comprehensive Conservation Plan National Wildlife Refuge

              U.S. Fish & Wildlife Service
Crescent Lake
Comprehensive
Conservation Plan
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 Lake
National Wildlife Refuge
Comprehensive Conservation Plan
September 2002
Prepared by
U.S. Fish and Wildlife Service
Crescent Lake/North Platte National Wildlife Refuge Complex
115 Railway Street, Suite C109
Scottsbluff, NE 69361-3190
and
Crescent Lake National Wildlife Refuge
10630 Road 181
Ellsworth, NE 69340-6801
Crescent Lake National Wildlife Refuge
Comprehensive Conservation Plan Approval
U.S. Fish and Wildlife Service, Region 6
Submitted By:
Steven A. Knode Date
Project Leader
Crescent Lake National Wildlife Refuge Complex
Concur:
Ron Cole Date
Refuge Program Supervisor
Richard A. Coleman, Ph.D. Date
Regional Chief
National Wildlife Refuge System
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
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 .......................................................................................................... 15
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
Wilderness ............................................................................................... 34
Research Natural Areas ....................................................................... 36
Upland Habitat .............................................................................................. 37
Subirrigated Meadow ............................................................................ 38
Sands, Choppy Sands, and Sand/Choppy Sands Mixed Habitat .... 40
Wilderness ...................................................................................................... 43
Wetland Habitat ............................................................................................44
Natural Lakes......................................................................................... 44
Artificially Managed Lakes .................................................................. 45
Fish and Wildlife ...........................................................................................47
Waterfowl ................................................................................................ 47
Ground-nesting Grassland Passerines, Owls, Harriers and
Shorebirds ........................................................................................ 48
Marsh Birds and Terns ..........................................................................49
Tree Nesting Species of Management Concern ................................49
Prairie Grouse ........................................................................................ 50
Mammals, Reptiles, Amphibians, Invertebrates and Fish .............52
Public Use .......................................................................................................
Interpretation and Recreation ............................................................ 56
Fishing ..................................................................................................... 57
Hunting .................................................................................................... 57
Cultural Resources ....................................................................................... 58
Lands and Facilities ......................................................................................58
Community Involvement / Support Systems ...........................................59
Lands of Interest .......................................................................................... 60
V. Implementation and Monitoring
Funding and Personnel ................................................................................62
Staffing Needed for Implementation..................................................62
Funding Needed for Implementation .................................................62
Refuge Management Policies and Guidelines ...........................................62
Partnership Opportunities ........................................................................... 63
Monitoring and Evaluation ..........................................................................63
Plan Amendment and Revision...................................................................63
Environmental Action Statement................................... 65
Finding of No Significant Impact (FONSI) .......66
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Appendices
A. Glossary .......................................................................................................... 68
B. Literature Cited / References..................................................................... 72
C. Legal and Policy Guidance........................................................................... 74
D. Operations and Maintenance Needs .......................................................... 77
E. Compatibility Determinations ....................................................................78
F. Crescent Lake NWR Species List ............................................................. 81
G. Minimum Tools for Wilderness Management ........................................... 88
H. Species of Special Interest ..........................................................................89
I. Step-down Management Plans ................................................................... 89
J. Section 7 .......................................................................................................... 90
K. List of Preparers / Review Team ............................................................... 92
L. Mailing List .................................................................................................... 93
M. Public Involvement / Consultation and Coordination ............................. 94
Maps
1. Vicinity Map ................................................................................................... 3
2. Base Map ........................................................................................................7
3. Region 6 Ecosystems.................................................................................... 17
4. Habitat Classification 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
Staffing Needed for Implementation ................................................................ 62
iii
Crescent Lake National Wildlife Refuge Comprehensive Conservation Plan - September 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 Comprehensive Conservation Plan - September 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 Comprehensive Conservation Plan - September 2002 3
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Crescent Lake National Wildlife Refuge Comprehensive Conservation Plan - September 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 Comprehensive Conservation Plan - September 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.
Crescent Lake National Wildlife Refuge Comprehensive Conservation Plan - September 2002 7
8 Crescent Lake National Wildlife Refuge Comprehensive Conservation Plan - September 2002
Crescent Lake National Wildlife Refuge Comprehensive Conservation Plan - September 2002 9
Cultural Resources
Historic, archaeological, and paleontological resources are protected by
Federal laws. No formal, systematic cultural resource surveys have been
onducted 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 Comprehensive Conservation Plan - September 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).
This goose, designed by J.N. “Ding”
Darling, has become the symbol of the
National Wildlife Refuge System.
Crescent Lake National Wildlife Refuge Comprehensive Conservation Plan - September 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
(published with the Draft CCP) and Compatibility Determinations
(Appendix E).
12 Crescent Lake National Wildlife Refuge Comprehensive Conservation Plan - September 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 National Forest - Interagency Fire Agreement
■ U.S. Geological Survey - Water resources management
■ Local landowners - FWS Partners for Fish and Wildlife Program
Crescent Lake National Wildlife Refuge Comprehensive Conservation Plan - September 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 Comprehensive Conservation Plan - September 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 (published with the Draft CCP).
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 Comprehensive Conservation Plan - September 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.
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).
16 Crescent Lake National Wildlife Refuge Comprehensive Conservation Plan - September 2002
Geology
During the Cretaceous period of the Mesozoic 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 4,000 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 Comprehensive Conservation Plan - September 2002 17
18 Crescent Lake National Wildlife Refuge Comprehensive Conservation Plan - September 2002
Crescent Lake National Wildlife Refuge Comprehensive Conservation Plan - September 2002 19
20 Crescent Lake National Wildlife Refuge Comprehensive Conservation Plan - September 2002
Crescent Lake National Wildlife Refuge Comprehensive Conservation Plan - September 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 Comprehensive Conservation Plan - September 2002
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.
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
Crescent Lake National Wildlife Refuge Comprehensive Conservation Plan - September 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 sighting 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 Comprehensive Conservation Plan - September 2002
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.
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
Crescent Lake National Wildlife Refuge Comprehensive Conservation Plan - September 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.
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.
26 Crescent Lake National Wildlife Refuge Comprehensive Conservation Plan - September 2002
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.
Figure 3. 1997-1999 Raptor Breeding Survey Results
Species Average Breeding
Pairs
Average No.
Young
Red-tailed hawk
Swainson's hawk
Bald eagle
Great horned owl
Northern harrier
American kestrel
Barn owl (in nest
structures)
2
5
1
28
4
8
4 (est.)
82
3
Unknown
15
24
Crescent Lake National Wildlife Refuge Comprehensive Conservation Plan - September 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 tiger salamander, northern
prairie lizard, bullsnake, garter snake, and box turtle (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 Comprehensive Conservation Plan - September 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 Comprehensive Conservation Plan - September 2002 29
30 Crescent Lake National Wildlife Refuge Comprehensive Conservation Plan - September 2002
Crescent Lake National Wildlife Refuge Comprehensive Conservation Plan - September 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 Comprehensive Conservation Plan - September 2002
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.
“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
Blowout penstemon, University of Nebraska
Crescent Lake National Wildlife Refuge Comprehensive Conservation Plan - September 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 five small areas in the
Nebraska Sandhills. The remainder of the turtle’s range extends from
southern Nebraska through Texas and into Mexico. On the Refuge, it is
found almost exclusively at Gimlet Lake. A second large population occurs
at Rush Lake, just off the Refuge. Refuge population estimates range from
3,000 to 4,000. These turtles migrate across the County road twice a year
and are especially vulnerable to road kill and predation at those times.
Improvements in the County road along Gimlet Lake could result in
increased mortality from vehicles due to more traffic and higher speeds. 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 Comprehensive Conservation Plan - September 2002
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 size 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 restore the wilderness qualities of the Proposed
Wilderness Area.
One of the objectives for the Refuge is to reintroduce bison into the Poposed
Wilderness (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 Proposed Wilderness 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.
In fact, bison tend to create blowouts that would be beneficial to the
endangered blowout penstemon.
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.
Crescent Lake National Wildlife Refuge Comprehensive Conservation Plan - September 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
Proposed Wilderness, 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 until the decision whether or not to reintroduce
bison is made.
Interim Strategies (without the presence of bison):
■ Prepare, by May 1, 2003, 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 Comprehensive Conservation Plan - September 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 when in compliance with the Natural Area
Management Plan (8 RM 10.8 H).
■ 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 Comprehensive Conservation Plan - September 2002 37
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.
“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)
38 Crescent Lake National Wildlife Refuge Comprehensive Conservation Plan - September 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 Comprehensive Conservation Plan - September 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:
n 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
25 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 Comprehensive Conservation Plan - September 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 Comprehensive Conservation Plan - September 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.
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 Comprehensive Conservation Plan - September 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. The Refuge currently has 180 blowouts
that historically have had penstemon. They average about 10 yards in
diameter; some larger, some smaller. Within the five habitat units, we found
80 penstemon plants in 2002.
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.
■ Monitor the success of each action taken to verify and quantify results.
Crescent Lake National Wildlife Refuge Comprehensive Conservation Plan - September 2002 43
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.
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 Comprehensive Conservation Plan - September 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.
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.
Crescent Lake National Wildlife Refuge Comprehensive Conservation Plan - September 2002 45
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 Comprehensive Conservation Plan - September 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 Comprehensive Conservation Plan - September 2002 47
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.
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.
“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
Ruddy duck © Cindie Brunner
48 Crescent Lake National Wildlife Refuge Comprehensive Conservation Plan - September 2002
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.
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.
Short-eared owl © Cindie Brunner
Crescent Lake National Wildlife Refuge Comprehensive Conservation Plan - September 2002 49
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.
American Bittern © Cindie Brunner
50 Crescent Lake National Wildlife Refuge Comprehensive Conservation Plan - September 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 Comprehensive Conservation Plan - September 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 Comprehensive Conservation Plan - September 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.
White-tailed deer © Cindie Brunner
Crescent Lake Na