Updating the Illinois Wildlife Action Plan: Using a Climate Change Vulnerability Assessment to Inform Conservation Priorities

Katherine Kahl, Kimberly Hall, Jeffery Walk, Sarah Hagen, Aaron Lange, Patrick Doran
Created: 3/15/2012 - Updated: 3/02/2020


The Nature Conservancy’s vision of “climate-smart” conservation seeks to anticipate human responses to climate change, and considers the benefits to people that result from our actions to protect and restore nature. One key area for engagement and partnership has been work on state Wildlife Action Plans (WAP). This case study describes a vulnerability assessment of 163 species comprising eight taxonomic groups from Illinois’ list of “Species in Greatest Need of Conservation” designated in the state’s Wildlife Action Plan.


In 2005, Congress charged that all states and territories create a WAP to help conserve wildlife and natural areas before they become rarer and more costly to protect. States were required to develop these plans to continue receiving federal funds through the Wildlife Conservation and Restoration Program and the State Wildlife Grants Program. Like other states, Illinois developed strategic actions in their WAP by working with a broad array of partners including scientists, sportsmen and women, conservation organizations, and communities. Illinois developed a WAP that the state Department of Natural Resources (DNR) and partners have been operating under since 2005. The Illinois chapter of The Nature Conservancy (TNC) was contacted by the DNR in 2009 to evaluate a subset of Species in Greatest Need of Conservation identified in the WAP for climate vulnerability. This opportunity for TNC and DNR to partner on a key piece of the WAP update process was attributed to several factors: 

  • Motivation for states to engage in climate change assessments:  Proposed 2009 “Cap and Trade” legislation (American Clean Energy and Security Act of 2009), which, if passed, could have provided a source of funding for adaptation actions outlined in state Wildlife Action Plans;
  • Initial guidance on how to get started:  The publication of the Association of Fish & Wildlife Agencies’ Voluntary Guidance for States to Incorporate Climate Change into State Wildlife Action Plans & Other Management Plans;
  • Demonstrated experience:  TNC-Illinois’ role in integrating climate information into Chicago Wilderness’s Climate Action Plan for Nature and ongoing work contributing to the Climate Change Update to the Biodiversity Recovery Plan. Chicago Wilderness is an alliance of over 250 state, federal and NGO partners working on conservation issues in greater Chicago;
  • Understanding of IDNR needs:  Dr. Jeff Walk, who had coordinated the first WAP while working for DNR, was now TNC-Illinois’ Science Director; and
  • An opportunity to help move Illinois forward:  Engagement on the WAP update was seen as an opportunity for TNC to increase our understanding of the vulnerabilities of key species, and help influence Illinois’ conservation agenda, with an end goal of engaging practitioners statewide to actively address climate change.

Funding for the climate change update to the Illinois Wildlife Action Plan was provided in part by U.S. Fish and Wildlife Service and the Illinois Department of Natural Resources. Funding for TNC’s climate change adaptation case study series was provided by the Kresge Foundation.


Scientists at TNC-Illinois used NatureServe’s Climate Change Vulnerability Index to rank the vulnerability of 163 Species of Greatest Conservation Need listed in Illinois’ WAP. This work compares patterns of species vulnerability across the state’s natural divisions and major watersheds, reviews key impacts on habitats, and suggests important strategies that managers can employ to help species and systems adapt. Assessing the climate change vulnerability of these species represents a critical first step toward including climate considerations in the next update to the WAP. 

The climate update to the WAP, along with this companion case study, provides:

  • Data.  The vulnerability ratings for Illinois’ Species in Greatest Need of Conservation provide new insights into 1) how species and systems may respond to changes in climate and 2) strategies that we can employ to help;
  • Action.  The process of assessing vulnerabilities and linking them back to possible management actions has provided some immediately actionable insights, like the need to update engineering standards for constructed wetlands to accommodate more intense rainfall events, and thus preserve water quality; and
  • Guidance for managers.  A key aspect of updating work to incorporate climate change involves questioning assumptions and “business as usual” practices.

The goal of this case study is to show how information is being used to advance conservation strategies that consider future climate threats, and to illustrate how and why climate change has been incorporated into current projects. It is intended to promote learning and provide opportunities for discussion among partners in resource protection and restoration. Through this dialog, we hope to help clarify what “adaptation” means by providing clear examples of how linking climate impacts to the viability of our conservation targets leads us to change how we work, where we work, or the partners we engage.

The Challenge in Illinois

Predicting how temperature, intensity of storm events, and drought stress might impact the wide range of species that state agencies are tasked with managing is a daunting challenge. As a first step to updating the WAP, the Illinois DNR wanted to more fully understand potential climate-related impacts on Species in Greatest Need of Conservation identified in the WAP. Conducting a climate vulnerability assessment for these species was seen as a tool for integrating climate change vulnerability and adaptation into the conservation conversation for DNR, their conservation partners, and policymakers in Illinois.  

How is Climate Projected to Change in Illinois?

A key component of assessing climate vulnerability is understanding “exposure,” or the extent to which a species or system is expected to experience a change in climate. By the middle and end of the 21st century, conditions in Illinois are likely to be characterized by:

  • Winters that are “less cold” (in particular, higher minimum temperatures)
  • Increases in peak storm events, especially in winter and spring
  • More flooding
  • Generally lower water levels in lakes and reservoirs
  • Growing season up to six weeks longer
  • Increased summer heat and drought

A climate change vulnerability assessment links these forms of exposure to the sensitivities of a species or system (e.g., temperature tolerance, drought tolerance, ability to survive if stream flow changes), while also considering that species’ or system’s ability to adapt (e.g., tolerate variation, move to a new location). In many cases, a species’ or system’s ability to adapt may be constrained by things managers can influence, such as the presence of invasive species that act as competitors for resources or lack of suitable habitat through which a species can move to reach a more suitable climate. Taking actions to address these concerns can be “climate-smart” adaptation strategies.

TNC-Illinois assessed the climate change vulnerability for 163 species within eight taxa. This assessment excluded species with little-known life history information, those extirpated from the state or birds that only occur in the state during migration. All remaining crustacean, amphibian, reptilian, and mammalian Species in Greatest Need of Conservation were assessed. Scientists randomly selected 20-30 species of mollusks, insects, fish, and birds among the remaining candidate species until a similar number of species would be assessed among taxonomic groups. A complete list of species assessed can be seen in the full report. The assessment was conducted by natural division for terrestrial species and by watershed for aquatic species. A regional resolution was chosen (over a statewide assessment) to account for local landscape factors and therefore, to assess regional differences in species vulnerability; this was intended to better inform the state’s wildlife management and conservation planning.

Illinois staff collaborated with TNC’s Great Lakes Climate Change Scientist, Kim Hall, to use NatureServe’s Climate Change Vulnerability Index to assess climate change vulnerability. NatureServe’s Index was chosen because it provides a consistent framework for assessing the climate change vulnerability for many species in a relatively short amount of time. After entering data related to exposure to changes in temperature and drought stress (see http://climatewizard.org), users answer a series of questions to identify up to 29 factors related to other types of exposure, sensitivity, and adaptive capacity. The Index returns a relative vulnerability rating for the species in the assessment area and identifies factors associated with vulnerability; this output provides a foundation to begin adaptation planning. 

Assessment Findings

The Index provides a vulnerability rating, on a scale from “Extremely Vulnerable” up to “Population Increase Likely” (least vulnerable). In an effort to ensure and measure consistent and repeatable outputs from the Index, TNC scientists provided input data for the same 25% of species (n=128) to compare output vulnerability ratings. None of the scientists were subject experts for all taxa but all had expertise to locate and synthesize input factors required by the tool. They achieved the same vulnerability rating in 59.4% of cases. In an additional 38.3% of cases, the Index returned two agreeing ratings and one rating a single rank higher or lower. This is interpreted as a nearly 98% repeatability of results. The high proportion of similar results suggests NatureServe’s tool is robust for a variety of users, and thus useful for making broad comparisons across groups of species, and can be repeated over time with consistent outcomes. An overall look at the variation in climate change vulnerability ratings among taxonomic groups is shown in Figure 1.

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Fig. 1.  Climate change vulnerability ratings were assigned to 163 “Species in Greatest Need of Conservation” within eight taxonomic groups, designated in the Illinois Wildlife Action Plan.

Outcomes and Conclusions

The assessment identified several important findings and insights:

  • Aquatic species in cool water or headwater streams (i.e., mollusks and fish), as well as some amphibians associated with temporary pools, showed high vulnerabilities to climate change. Risk factors suggested by the Index included increases in temperature with often limited potential for movement into cooler systems (either due to low ability to move, or the presence of barriers), and the potential for changes in the hydrologic regime (e.g., stream flow), including seasonal drying of small streams or wetlands. Mollusks in particular stand out as often scoring Extremely or Highly Vulnerable due to a strong reliance on other species (often fish) that act as larval hosts, and would also likely be sensitive to changes in hydrology. Insects overall were moderately threatened. In general, the Index suggests that species associated with smaller ecological systems, like a small stream with variable flow, are likely to be more vulnerable than species associated with larger systems (e.g., larger river system) due to the potential for changes in hydrology.
  • The Index is sensitive to the related factors of dispersal ability and habitat connectivity.  Species with limited ability to disperse and highly specific habitat requirements (e.g., small-bodied species) had higher vulnerabilities. Similarly, when species were assessed in sub-sections of the state with more barriers and less natural habitat, the Index scores tended to indicate higher vulnerability. For example, terrestrial species tended to have higher vulnerabilities in natural divisions that were highly developed or agriculturally dominated. An understanding of habitat requirements and dispersal abilities of individual species are crucial when reviewing Index assessment results in the context of developing conservation strategies.  
  • This Index only takes climate change threats for a geographic area into account, not the full suite of threats that may be present for a particular species. The large number of birds and mammals that received largely stable assessment scores was surprising. This result reflects their typically general habitat requirements, lack of strong dependence on a particular hydrologic regime or some form of strong species interaction (i.e., pollinator-plant relationships), and ability to move to more suitable areas if they are available. Although many of these species may be less vulnerable than species that can’t easily disperse, it is important to recognize a few caveats associated with this result. The result is focused on vulnerability in Illinois, as subdivided by natural division or watershed. The Index does not address whether habitat might be available for species to move into, and does not account for vulnerabilities that migratory species face along their migratory routes or on wintering grounds. Care must be taken to interpret results in the broader context of information known about a species and its habitat. These results should not imply that conservation resources are not needed to protect bird and mammal species. 
  • Species vulnerability varies across the state and by taxa.  Figure 2 shows the distribution of the 162 species assessed by watersheds (fish, mussels, stream-dwelling crustaceans) and by natural divisions (mammals, birds, reptiles, amphibians, insects, cave-dwelling crustaceans). The darkest colors indicate areas with the highest percentages of species vulnerable to climate change per vulnerability assessment ratings. Managers can use this data, along with additional information for species and systems, to help plan and prioritize conservation efforts. For example, considering these results when developing a connectivity strategy could provide insight into targeting and prioritizing viable networks of lands and waters that have long-term potential to sustain biodiversity.

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Fig. 2.  The figures show the distribution of these species by watersheds (fish, mussels, stream-dwelling crustaceans) and by natural divisions (mammals, birds, reptiles, amphibians, insects, cave-dwelling crustaceans). The darkest colors indicate watersheds and natural divisions with the highest percentages of species vulnerable to climate change per vulnerability assessment ratings. 

  • Consider species’ range shifts/northward range expansion.  One piece of information that is required by the Index is the position of the assessment area within the full geographic range of the species being assessed. As part of the assessment, the TNC team found that about 8% of species assessed occur at the southern edge of their range in Illinois while 15% occurred at the northern edge of their range in Illinois. The Index takes these kinds of range characteristics into account within its assessment score. For example, mobile species that are more common in southern Illinois, and at their northern range limit there, often receive a score of “Increase likely” (e.g., a range shift that leads to expansion of the range further into Illinois may occur).  Northward range shifts are generally forecast for mobile species in the Midwestern United States, though changes in land use and interactions with other species can result in range expansion or contraction in any direction. This has important and broader implications for:
    • designating Species in Greatest Need of Conservation at the edge of their ranges,
    • understanding the context of a species’ abundance or rarity compared to that within the rest of its range, and
    • prioritizing conservation investment.  

The question of whether to invest time and financial resources into a species whose population may be shifting (northward) out of the state is one that should be considered within larger, long-term conservation planning efforts.   

How can these findings be applied on the ground?

Examples of how to think through incorporating climate change adaptation or mitigation for the eight target systems in the WAP (i.e., Streams, Forest, Farmland & Prairie, Wetlands, Invasive Species, Land & Water Stewardship, Green Cities) can be seen in Table 1 (see Project Documents). Each action and climate consideration is traced back to the reported climate change vulnerability of an individual species from the Species in Greatest Need of Conservation list and/or the projected changes likely to affect the habitats on which those species depend. In Table 1, “2005 WAP Conservation Actions” are examples of the broad-scale strategies from the original WAP. “Climate Change Considerations” describe why those actions are relevant and how they may need to be modified or applied differently given the anticipated effects of climate change on species, habitats and processes. “Who Will Benefit & Where” describes some of the places and Species in Greatest Need of Conservation (bold) affected by the modified action, as well as benefits to people.



With the assessment and recommended considerations now available, Illinois conservation practitioners have the information at hand to begin developing and deploying informed, site-specific conservation efforts and begin implementing adapted conservation practices under the umbrella of the WAP. High priority action items include: 1) As a strategy for reducing sediment and nutrient loads in waters draining from agricultural and developed areas, engineering standards for constructed wetlands need to be revised to account for more frequent high-precipitation events to avoid failure; 2) Chicago Wilderness’ vulnerability assessments, already underway, will help prioritize species and habitat within their regional long term conservation strategies; and 3) Locations for endangered species reintroductions are being reconsidered based on the potential for long-term viability and stewardship, rather than only locations of historical occurrence.


Overall, the process is generating new ideas about a long-term conservation vision for the state. In developing the WAP, partners identified “Conservation Opportunity Areas” (COAs), locations with particular importance to conserving the diversity of the state’s wildlife. Many COAs are the “biggest and best” examples of grasslands, savannas, forests, wetlands, and streams. Viewed through the lens of climate change, COAs represent a set of core areas to sustain populations on the Species in Greatest Need of Conservation list. The network of rivers and streams in Illinois, and the concentrations of wetlands and forests along them, will be crucial corridors for species migrations, and linking conservation in Illinois to other states in the region. Conservation efforts in the matrix of working lands and developed areas are important to protecting livelihoods, providing outdoor recreation opportunities, and sustaining the quality of life of the state’s residents. Strategic use of agricultural Best Management Practices, such as constructed wetlands and riparian buffers, help sustain agricultural productivity while improving drinking water quality. A focus on floodplain restoration and reconnection will minimize the damage that increased flooding will cause to homes and businesses.   

This case study highlights some key questions that will provide useful discussion topics as WAP teams develop their updates:

  1. How do we plan for potential species range shifts and what priority should be given to species on the edge of their range?
  2. How are we treating rare species?  Especially those who are rare in the state largely because their range only slightly overlaps the state boundary but are common elsewhere?
  3. What are the fundamental species, habitats and processes we are trying to conserve and how are they likely to be affected by direct and indirect climate changes?
  4. Are current conservation actions likely to sustain targets in the near and long term?  Should additional targets be added? Should any current targets be dropped?
  5. Given the ever-increasing amount of information on climate change, experience with this climate change update and knowledge of the results, do we need to “take a step back” and review the eight U.S. Fish and Wildlife Service WAP Required Elements?
  6. How do we do a better job sharing information, and sharing management responsibility, with managers beyond state borders? Engaging in collaborative “think tank” opportunities like the Climate Adaptation Collaboratory (adapt.nd.edu) could be a novel way of sharing techniques and best practices with other adjacent states working toward common conservation goals.


Information submitted by project lead and reviewed by CAKE Content Editor.

Project File (s)

Illinois Comprehensive Wildlife Conservation Action Plan and Strategy Confronting Climate Change in the U.S. Midwest: Illinois


Kahl, K., Hall, K., Walk, J., Hagen, S., Lange, A., & Doran, P. (2011). Updating the Illinois Wildlife Action Plan: Using a Climate Change Vulnerability Assessment to Inform Conservation Priorities. Ed. Rachel M. Gregg. [Case study  on a project of The Nature Conservancy – Great Lakes Project]. Retrieved from CAKE: http://www.cakex.org/case-studies/updating-illinois-wildlife-action-pla… (Last updated March 2012)

Project Documents

Table 1. Examples of WAP Conservation Actions with considerations for climate change adaptation/mitigation Figure 1. Climate change vulnerability ratings assigned to 163 “Species in Greatest Need of Conservation” Figure 2. Distribution of species by watersheds and natural divisions

Project Contact(s)

Email: kkahl@tnc.org
Position: Climate Change Ecologist

The Great Lakes Project is focused on the protection, restoration and maintenance of the region’s most critical natural systems while safeguarding the lakes from their most significant threats, such as aquatic invasive species.

The Nature Conservancy’s Great Lakes Project has identified six priority areas to build strategic success:

The Nature Conservancy in Illinois works with partners across the state to protect nature and preserve life.

The Illinois Department of Natural Resources has a strong impact on the economy of the State of Illinois. From coal mining to agriculture to tourism, the economic effects of IDNR activities reach statewide. Activities associated with IDNR support 90,000 jobs and at least $32 billion worth of economic impact annually.