Crab Orchard National Wildlife Refuge: Habitat Management Plan


The Refuge is currently working to incorporate climate change considerations into their Habitat Management Plan. 

Crab Orchard National Wildlife Refuge is a 43,890 acre refuge in southern Illinois that provides significant resting areas for migratory birds utilizing the Mississippi Flyway and is visited by approximately 1 million people per year.

Project Area

Crab Orchard National Wildlife Refuge (NWR) is located in the southern portion of Illinois, with lands in Williamson, Jackson, and Union counties. The Refuge has begun work on a habitat management plan, or HMP. An HMP is a dynamic working document that provides Refuge managers a decision-making process; guidance for the management of Refuge habitat; and long-term vision, continuity, and consistency for habitat management on Refuge land. The primary purpose of the HMP is to implement the habitat related elements of the Comprehensive Conservation Plan (CCP), completed in 2007. Fish and Wildlife Service Policy, specifically 620 FW 1, states that “The refuge manager may modify the CCP and/or HMP if significant new information suggests the plans are inadequate or refuge resources would benefit from the changes. The appropriate level of NEPA compliance is required if we propose significant changes.”” The HMP for Crab Orchard NWR will result from a NEPA process to address additional aspects of habitat management that were lacking in the CCP and, where necessary, modify CCP goals or objectives in light of new information and understandings of resource needs.

Management Goals

The refuge has four primary purposes:Crab Orchard Lake shoreline

  • Wildlife conservation: The Refuge exists to protect, enhance, and manage natural resources and the Refuge landscape through an ecosystem approach that sustains optimum populations of migratory waterfowl, native fish and wildlife species, and threatened and endangered wildlife.
  • Agriculture: The Refuge seeks to provide opportunities for and encourage agricultural uses that help attain wildlife conservation goals, benefit the local economy, and are compatible with other Refuge purposes.
  • Industry: The Refuge manages an industrial complex fully utilized by compatible tenants that conform to prescribed safety, health, environmental, and maintenance standards.
  • Recreation: The Refuge provides safe and equitable public use programs and facilities so that visitors have an enjoyable recreational experience and gain an appreciation for fish and wildlife resources, natural and cultural history, outdoor ethics, and environmental awareness


In particular, the HMP that will be developed during this planning process will restate the habitat goals, objectives, and strategies identified in the CCP that are found to be adequate.  Additional goals and objectives will be developed and then the HMP will further define the habitat related objectives and describe specific prescriptions for the habitat management strategies identifying how, when, and where they will be implemented. Objectives for the HMP are still being developed and will include public involvement.  However for the purposes of this exercise, staff at the Refuge developed several potential habitat management ideas  that could inform the objectives in the HMP.  These are outlined in the table. The Refuge used the Adaptation Workbook in Forest adaptation resources: Climate change tools and approaches for land managers (Swanston and Janowiak 2012) to evaluate the impacts of climate change on the Refuge and its ability to meet management objectives.  Potential actions to adapt to those changes were identified as part of the process.

Climate Change Impacts

In forested areas, northern mesic species such as sugar maple are projected to decline, while southern oak species such as post oak are project to increase in habitat suitability. fall colors on the RefugeFuture habitat suitability for many native oak and hickory species is unclear, with slight declines projected under a warmer, drier climate scenario and increases under a wetter scenario with less warming. Shortleaf pine is a species that was planted in the area for erosion control in the past, but is not native to the area. Models suggest that habitat suitability for this species is projected to increase. The Refuge provides a mix of habitats for waterfowl and neotropical migratory birds. The Climate Change Bird Atlas was used to determine how climate change may affect avian habitat suitability (Matthews et al. 2011). Focal species projected to experience an increase in breeding habitat include Acadian flycatcher, chuck-will’s widow, and Kentucky warbler. Habitat could remain stable for blue-gray gnatcatcher and whip-poor-will. Some species may experience a slight decline in habitat suitability, such as cerulean warbler, wood thrush, and yellow-billed cuckoo. In addition to the species featured in the Bird Atlas, Refuge managers also discussed how fewer Canada geese are overwintering in the area, presumably because they are staying further north due to milder winters. Some preliminary model results from another study suggest that overwintering habitat suitability may increase in the area for wood duck (National Audubon Society 2014). Information on climate change impacts to other species and habitat types is more limited. In grasslands, no model information is currently available for vegetation, but some information is available for grassland birds (Matthews et al. 2011). Some species such as dickcissel, field sparrow, and grasshopper sparrow could experience a decrease in habitat suitability. Prairie warbler, loggerhead shrike, eastern meadowlark, and northern bobwhite are expected to remain stable or experience a slight increase in habitat suitability. Climate change impacts to southern Illinois are summarized in the Central Hardwoods Ecosystem Assessment and Synthesis (Brandt et al. 2014). Key impacts include:
Warmer temperatures and longer growing seasons (especially warmer winter lows)
More extremely hot days
Wetter springs followed by more prolonged summer droughts
More frequent heavy precipitation events
Changes in hydrology, including increased risks for flash floods
Greater risk of wildfire
Increased risk and spread of various diseases and insect pests
Shifts in habitat suitability for many of the dominant tree species, with generally more northern species projected to decline and southern species projected to increase
Shifts in habitat suitability for many focal bird species.

Challenges and Opportunities

Climate change may make meeting some management objectives for forested areas on the Refuge more challenging, but it may also create management opportunities:


Shifts in spring and summer precipitation may make it more difficult to complete prescribed burns duing those seasons
Later in summer or in fall, wildfire probability and intensity could increase under hot, dry conditions
There may be more invasive species to manage due to milder temperatures
Some oaks and hickory species that the Refuge is currently managing to increase in basal area may not do well under future climate conditions toward the end of the century
More southern shade- tolerant speciesthat are projected to increase in suitable habitat, such as yellow poplar and sweetgum, may out-compete oak species
In grasslands, wetter springs could affect planting, burning, and mowing windows
With more seasonal variability and weed pressure, agricultural yields could decrease
Weather conditions might impact field access and planting windows and could disrupt the 3-year rotation for certain, more low-lying fields
In aquatic systems, increases in precipitation and drought events could impact the ability of the Refuge to manage water levels to provide breeding and foraging habitat for amphibians and migratory birds


In forests, habitat suitability for sugar maple is projected to decline, which may make reducing that species component easier. As maples decline and die, it could create gaps for oak regeneration.
Managers may be able to carry out prescribed burns more frequently in the fall due to favorable conditions in that season. Fall burns could be beneficial for controlling invasives such as honeysuckle and autumn olive that remain green later into the fall.
Fire-adapted species, such as oak species, may be more resilient to climate-induced increases in wildfire risk
In grasslands, enhanced conditions for fall prescribed burns could be beneficial for controlling fescue
In riparian areas, increased precipitation could prioritize where bank stabilization is most crucial

Adaptation Actions

The Refuge evaluated a list of potential adaptation strategies and approaches in Forest adaptation resources: Climate change tools and approaches for land managers (Swanston and Janowiak 2012).  Below are some tactics discussed for further consideration in the HMP based on their perceived feasibility and effectiveness.

Mixed hardwood and upland forest
1.5. Restore or maintain fire in fire-adapted ecosystems.
2.2. Prevent the introduction and establishment of invasive plant species and remove existing invasive species.
3.1. Alter forest structure or composition to reduce risk or severity of wildfire.
5.2. Maintain and restore diversity of native species.
Control and monitor invasive forest plants
Use herbicides, fire, and mechanical removal
Evaluate possibilities of biological control
Favor fire adapted species
Carry out low intensity burning
Mixed hardwood upland forest, pine plantations, mixed hardwood/pine plantation
8.1. Use seeds, germplasm, and other genetic material from across a greater geographic range.
8.2. Favor existing genotypes that are better adapted to future conditions.
9.1. Favor or restore native species that are expected to be adapted to future conditions.
9.3. Guide changes in species composition at early stages of stand development.
Underplant oaks where needed following harvest or fire
Examine nursery stock and determine if it will have the species/genotypes that are most likely to do well
Mixed hardwood bottomland forest
2.2. Prevent the introduction and establishment of invasive plant species and remove existing invasive species.
9.1. Favor or restore native species that are expected to be adapted to future conditions.
9.3. Guide changes in species composition at early stages of stand development.
Control and monitor invasive forest plants
Use herbicides, fire, and mechanical removal
Explore possibilities of biological control
Use early detection rapid response (EDRR) for species with ranges identified to move northward
Provide and maintain wood duck habitat (# cavity trees per acre) and food sources (32% mast-producing trees per acre) by reforesting a designated amount of acreage into bottomland forest
Plant favorable species


Monitoring variables will be determined after development of the Habitat Management Plan and Inventory and Monitoring Plan, utilizing formalized peer reviewed monitoring protocols.

Project Photos

Click to enlarge photos

Project Videos

Next Steps

Information from this exercise will be incorporated into the Habitat Management Plan for the Refuge.

Learn More

To learn more about this project, contact Leslie


Invasive species, Lowland/ bottomland hardwoods, Plantations, Upland hardwoods, Water resources, Wildlife habitat

Last Updated

Thursday, January 25, 2018