Making Connections for Wildlife

Aligning Transportation Projects with State Wildlife Action Plans: A Step-by-Step Guide for Integrated Conservation Planning

Table of Contents

Who Should Use this Guide?

This guide is designed for anyone interested in aligning state transportation planning with wildlife conservation planning, as described in each state’s Wildlife Action Plan. The case study in Colorado, which served as the pilot project for developing this guide, was led by a non-profit organization, the Southern Rockies Ecosystem Project. However, this model can be adapted by any group or individual wishing to spearhead a process for integrating the goals and objectives of a State Wildlife Action Plan into that state’s transportation planning processes. The mapping of wildlife linkage areas does require technical expertise – these steps should be conducted by Geographic Information Systems (GIS) professionals either within the wildlife agency or by an outside consultant or non-profit group with the appropriate expertise (as in the case of the Colorado project). Regardless of who starts the process, the most important thing in pursing this model is the development of collaborative interagency relationships to ensure that the needs and concerns of both the state wildlife agency and the state transportation agency are addressed.

What does this Guide Offer?

The following step-by-step guide provides a framework for ensuring that the early consideration of conservation priorities – specifically wildlife movement needs – that began in the long-range transportation planning process continues into the short-term planning processes, and that the necessary data are developed so that these needs can be appropriately addressed. Specifically, the guide outlines a process for developing high quality data with regards to identifying important areas for wildlife habitat connectivity, as identified by the State Wildlife Action Plan, and working with natural resource and transportation agencies to integrate these data into the project planning process. Work conducted in Colorado provides a case study for this guide. Funding for the development of this guide and the Colorado pilot project was provided by the Wildlife Conservation Society and the Doris Duke Charitable Foundation.

Overarching Goal

Protect and restore landscape connections amidst a large and growing transportation infrastructure by integrating conservation needs identified by State Wildlife Action Plans with the transportation planning process.


Priority Conservation Need: Avoiding Wildlife Impacts and Placing Effective Mitigation in Transportation Planning

Animals move on a daily, seasonal and lifetime basis to meet their needs for forage, habitat and breeding. The importance of habitat connectivity to ecosystem functionality is well documented in the literature (e.g., Noss and Cooperrider 1994; Noss 1983) affecting both terrestrial and aquatic wildlife. Human developments and activities often create barriers to wildlife movement, preventing these needs from being adequately met. Restrictions on these movements affect wildlife at all spatial scales, impacting individual animals as well as populations and even species. Because of these impacts, habitat fragmentation is now recognized as one of the greatest threats to biodiversity and the decline of species worldwide (Ehrlich 1986; Wilcove et al. 1998).

Transportation infrastructure, in particular, is a principal cause of habitat fragmentation, with negative impacts on wildlife (e.g., Harris and Gallagher 1989; Maehr 1984; Reed et al.1996). Animals are frequent victims of roadkill (Forman et al. 2003) as they move from one part of their range to another, or they may avoid roads altogether (Gibeau and Heuer 1996), limiting their habitat area and ability to fulfill certain needs. The impacts are pervasive – a 16 foot-wide road removes approximately two acres of habitat per mile of road, and it is further estimated that the impacts of the road (noise and edge habitat) extend at least 600 meters beyond the road footprint on either side of a roadway (Forman and Deblinger 2000).

In 2005, every state in the nation was required to complete a State Wildlife Action Plan, intended to guide the conservation of species of greatest conservation need and the habitat they depend upon. White et al (2007) note that every state’s plan identifies transportation infrastructure and associated traffic as a threat to key and at-risk species in their state. Several state plans specifically recommended greater coordination with state transportation officials.

Early consideration of conservation needs in the transportation planning process therefore offers an important opportunity for addressing the threat of habitat fragmentation (White et al 2007). Cramer and Bissonette (2007) report in their nationwide survey of transportation and ecology professionals that early incorporation of wildlife mitigation needs into the transportation programming, planning and design process was identified as the number one priority across all states in dealing with roads and wildlife. In order to proactively integrate conservation and transportation planning, planners must have access to high quality conservation data that describes where important conservation resources are located across the landscape, and what the conservation needs are for different types of resources.

The 2005 federal transportation bill, Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU) which funds the U.S. highway program through 2009, specifically recognizes the need to incorporate conservation needs with transportation planning, requiring that state transportation agencies consult with state and federal land management, natural resource and wildlife management agencies in the development of long-range transportation plans (typically a 20-30 year time frame). Each consultation is to include a comparison of the transportation plan with conservation maps and recommend potential mitigation actions.

Such consultation in long-range transportation planning is an essential first step in laying the foundation for early consideration of conservation needs and providing access to natural resource data sets in the long-range planning process. While still a very coarse level of planning, this is the first opportunity for identifying potential conflicts with

wildlife, setting the groundwork for further assessment – and funding – in the Statewide Transportation Improvement Plan (STIP), which sets transportation priorities over a 3-5 year time frame (see Fig. 1 for flowchart of the transportation planning process). At this stage of long-range planning, broad-scale wildlife data, including conservation priorities as identified in the State Wildlife Action Plan, should be referenced to highlight where transportation projects intersect priority conservation areas.


Defenders of Wildlife report: SAFETEA-LU Conservation Provisions of Interest Section 6001

Example of Integrative Long-Range Planning:

National Capital Region Transportation Planning Maps

With SAFETEA-LU in place, states now have the much-needed framework and regulatory mandate for considering conservation needs in long-range transportation planning. However, there is still a great need for timely integration of detailed and comprehensive conservation data in the STIP. Although transportation priorities are set well in advance of construction, most land and wildlife agencies are not notified in the early stages of project planning and design and, therefore, comment only during the permit review and environmental assessment stages, when transportation projects are well into the development process (Cramer and Bissonette 2007). At this point, changes to the project design typically result in significant delays, increased costs, and offer little environmental benefit. The need to coordinate between natural resource managers and transportation planners much earlier in the project planning process was identified as a specific need in a number of the State Wildlife Action Plans (White et al 2007) to ensure that appropriate avoidance and mitigation measures are implemented and located appropriately. Yet comprehensive data sets at much more refined scale – appropriate for project-level planning – are still lacking in many instances, and the processes for ensuring early consideration of these data are not in place in most states.

Resources from Defenders of Wildlife’s Habitat and Highways Campaign

Linking Conservation and Transportation: Using the State Wildlife Action Plans to Protect Wildlife from Road Impacts

Suggested Agenda for a Section 6001 Consultation Meeting

Getting up to Speed – Transportation for Conservation Advocates

Other Resources

State Wildlife Action Plans

State Wildlife Action Plans and the transportation planning process
Figure 1: Flowchart depicting the alignment of State Wildlife Action Plans and the transportation planning process, from long-range planning through construction, including the wildlife data needed at each stage in the process (Modified from White et al 2007).
Step One

Step One: Assemble Agency Partnership Team

Close collaboration with state transportation and wildlife agencies is the most essential element to developing a framework for ensuring early consideration of wildlife habitat connectivity data during the transportation planning process. Engaging people from both the transportation agency and the wildlife management agency is of critical importance – data can be updated and plans revised, but without the right players at the table even the best State Wildlife Action Plans cannot be implemented. Also recognize that the people involved in long-range transportation planning are not the same as those that are involved in short-term and project planning – each stage has different goals and objectives, and different data and information needs to meet these goals.

The purpose of the interagency partnership team is manifold: 1) to coordinate between the state wildlife and transportation agencies, 2) to determine at which point in the transportation project planning process wildlife data should be evaluated for possible conflicts, 3) to identify the appropriate personnel responsible for reviewing these data and determining the best measures for avoiding and/or mitigating impacts to these species, 4) to build a framework that educates personnel at all stages of the transportation project planning process on the value of integrating wildlife concerns early in the process to minimize costs and delays, while providing the greatest benefit to wildlife and driver safety. As each state Department of Transportation has different protocols for designing transportation projects, each state must individually determine the process that will be most effective for them in ensuring that wildlife concerns receive appropriate and early consideration.

Colorado Case Study

The Colorado State Wildlife Action Plan identifies habitat fragmentation due to transportation infrastructure as a high priority threat for all of the Tier 1 large and mid-sized mammals (lynx, gray wolf and swift fox). To maintain and restore habitat connectivity for these species, the plan highlights the need for wildlife crossings including wildlife over- and underpasses.

For our Colorado case study, we convened several meetings with a variety of staff from both the Colorado Department of Transportation (CDOT) and the Colorado Division of Wildlife (CDOW) including statewide and regional transportation planners, CDOT biologists, engineers, CDOW wildlife department head, and GIS staff from both agencies. The purpose was to engage personnel from both agencies representing the spectrum of personnel engaged in the development of a transportation project to ensure that the connectivity data itself and access to these data met the needs of different end-users. This approach allowed us to pinpoint the most effective point in the process for integrating these data, while ensuring that the data are appropriately used and interpreted for these purposes.


CDOW Regions
CDOW Areas
CDOW Districts
Colorado’s Comprehensive Wildlife Conservation Strategy

Questions to Ask

  • How does the State Wildlife Action Plan identify species of conservation concern? Is habitat fragmentation identified as a threat to these species? Are transportation impacts specifically identified as a threat? What recommendations are provided in the Plan for dealing with these threats?
  • Who should participate in the Interagency Partnership Team?
Department of Transportation Division of Wildlife*
  • Biologists
  • Environmental Clearance
  • GIS
  • Project Manager (Engineer)
  • Regional Planner
  • Statewide Planner
  • SWAP Coordinator
  • Wildlife Conservation Manager
  • GIS

* Note: individual species experts do not need to be involved in the Partnership Team, though their contributions are essential in developing the linkage models (Step 2)

  • How can we ensure upper-level support for this project from both agencies?
  • Seek a Letter of Support from the agency when developing the proposal.
  • Find (or create) an appropriate forum for presenting the proposal to upper-level directors (e.g., joint agency meetings, commission meetings)

Key to Success

  • Recognize the value in bringing diverse people together – from different agencies, as well as from statewide and regional offices within the same agency – to create a successful and easy-to-use system that is functional across the many layers of the agency. Even within the same agency, there may not be clear lines of communication among various departments. Use this collaboration as an opportunity to build communication channels between departments and agencies.
  • Work closely with agency partners to understand their goals, needs and concerns, and be ready to adjust the framework to best meets these needs and concerns.
  • Respect the processes that are already in place. The objective is not to impose, but to integrate into the existing system.

Ensure that people at all levels of the agency understand and are informed of the project – upper level support is necessary to permit staff to devote time and resources towards the project, and further ease data sharing and project ownership over the long-term.

Step Two

Step Two: Identify and Map Wildlife Linkages

The development of a spatially explicit wildlife linkages data layer involves multiple steps, each of which is outlined below. Once complete, these data can be overlaid with spatial data on upcoming transportation projects in the STIP to highlight potential conflicts with wildlife.

Researchers at Northern Arizona University recently developed Corridor Design, a freeware geographic information system (GIS) tool to assist with the linkage design process. This tool was developed to aid in the design of landscape-scale corridors in a heterogeneous environment. The ArcGIS tool encompasses a series of spatial analyses that walk the user through defining suitable habitat for target species, identifying core areas, finally, mapping the optimal corridors between core areas.

Corridor Design Tool Link

GIS Mapping Steps

The following steps should be pursued in close collaboration and communication with the Partnership Team, so that all members of the team – biologists and non-biologists alike – fully understand and participate in the analysis process. These steps are described below, however, for more information, we highly recommend that you also consult the Corridor Design webpage (see link, above).

GIS Mapping Step 1 – Identify Analysis Area(s)

Define what you are trying to connect. Identify and prioritize core and linkage areas. Several states, including Colorado, have completed statewide connectivity assessments, which can serve as the basis for identifying analysis areas for further definition using the Corridor Design tool.

Report: Inventory of States with Completed or In-Progress Connectivity Assessments

GIS Mapping Step 2 – Compile List of Target Species

Consider the following types of species:

    • Habitat specialists
    • Species with limited movement ability, or species that are sensitive to roadways or other types of barriers
    • Area-sensitive species that require large or well-connected landscapes to maintain a viable population and genetic diversity
    • Keystone predators, seed dispersers, etc
    • Species listed as threatened or endangered under the Endangered Species Act
      State species of concern.

In reviewing the selected suite of target species, make sure that the range of habitat types and ecological systems present within the analysis area are captured by the target species.

GIS Mapping Step 3 – Define Habitat Parameters and Compile Data Layers

A number of parameters must be defined for each target species to conduct the corridor modeling. Parameter definition should be conducted in close collaboration with each species biologist. Review of the parameters by several biologists is recommended, whenever feasible, and keep in mind that the parameters may require tweaking through several iterations in order to develop appropriate models.

There are four primary factors that are evaluated for each target species: land cover, elevation, topography, and distance from roads. Each of these criteria are weighted (0-100%), depending on the degree to which they influence a given target species’ habitat use. Each factor is given a percentage of its importance to the species so that the factors add up to 100%. The factors are then combined spatially to create the final HSM where every pixel has a value of the habitat importance to the species. Then, for each factor with a weight greater than zero the weighted geometric mean was calculated by raising each factor by its weight, and multiplying the factors.

If a particular target species’ habitat use cannot be adequately captured by these four factors, then the team may want to consider adding a new factor for that species (e.g., aspect, soil type). However, the makers of the Corridor Design tool argue, and we concur, that the use of few factors and few categorical metrics within each factor is better than many factors or numerous categories within a factor – complex models become increasingly abstract and are likely to be poor representations of what is actually occurring on the ground.

Other parameters that must be defined for each target species include minimum core patch size and daily dispersal distance. In addition, the team must determine how start and end points for each linkage analysis will be determined. In Arizona, protected area were used as start and end points, whereas in Colorado, in most cases, suitable habitat was used to define start and end points.

The primary data layers needed for the Corridor Design Analysis include: land cover (reclassified to a smaller number of habitat groupings), digital elevation model (30m resolution), and roads. Additional data layers may be needed if other factors were identified as primary influences on a given target species’ habitat preferences.

GIS Mapping Step 4 – Adapt Corridor Design Tool

The first step of adapting the Corridor Design tool is to define the areas of focus. More specifically, to identify areas where species are moving or potentially are moving through the landscape. Once the analysis area has been selected then the habitat suitability model can be clipped to the specific area for development of the habitat suitability model. The next step is to identify potential breeding patches and potential population cores.

Potential breeding patches = areas large enough to support one breeding event for one season.

Potential population cores = areas large enough to support a breeding population for approximately ten years.

To create the Habitat Suitability Model (HSM) for each species, each analysis cell of the land cover data layer is weighted based on the habitat preferences as defined by the species experts (Fig. 2).

Land Cover Weights:

1-3 = strongly preferred (1 is best)

4-5 = usable but suboptimal habitat

————————————————————- Suitability Threshold

6-7 = not breeding habitat, but occasionally used

8-10 = strongly avoided (10 is worst)

The suitability of the habitat is evaluated such that areas above the habitat threshold (i.e., weighted < 5) are joined into polygons of suitable habitat. Core habitat patches are created by combining all suitable and unsuitable habitat that falls within the designated daily dispersal distance, such that unsuitable habitat within a matrix of suitable habitat may be included in a core habitat patch. Suitable habitat beyond the species’ dispersal distance is not included in a core patch. Each habitat patch is then evaluated based on its size, relative to the minimum patch size needed to support a breeding event and the minimum patch size needed to support a core population for at least ten years – habitat patches smaller than these minimums are not considered core habitat.

Figure 2: Example of a Habitat Suitability Model
Figure 2: Example of a Habitat Suitability Model

Protected areas, species data on existing breeding populations or occupied habitat, or potential core habitat patches (derived from the HSM) are used to define the endpoints (actually areas) for the linkage analysis model. These endpoints define the area between which the linkage will be identified.

The Corridor Design analysis is performed creating a cost surface based on the HSM (Fig. 3). This is similar to a least-cost path analysis, but also incorporates suitable habitat patch sizes (i.e., small, stepping-stone patches that are too small to be core habitat patches, but may still be important as animals move between core habitat patches) and the species’ daily dispersal distance threshold. The resulting movement surface is a gradation that demonstrates the difficulty (i.e., cost) of moving between the two identified endpoints.

Figure 3: Example of a cost-surface
Figure 3: Example of a cost-surface

Based on this gradated movement surface, the next step is to determine an appropriate linkage width – this width is essentially a cut-off that defines the linkage area. The Corridor Design tool recommends creating slices of the lowest cost 0.1 to 10 percent of the total analysis area to define the actual linkage area (Fig. 4). This width requirement should be reviewed by the species experts.

The Corridor Design tool also provides the ability to combine individual species linkages into a multi-species linkages. In many cases, individual species linkages may overlap, highlighting the importance of specific portions of the linkage area for more then one modeled species. A multi-species approach is also recommended for indicating where appropriately designed mitigation can benefit multiple species.

GIS Mapping Step 5 – Biological review of species linkage models

A final review of the linkage models by the species experts is necessary to ensure that the linkages properly represent the species movement needs as accurately as possible and to determine whether any adjustments need to be made to the model inputs.

Figure 4: Example of linkages between two defined core habitat patches, with the recommended range of 0.1-10% of the analysis area displayed to define linkage width.
Figure 4: Example of linkages between two defined core habitat patches, with the recommended range of 0.1-10% of the analysis area displayed to define linkage width.

Colorado Case Study

GIS Mapping Step 1 – Identify Analysis Area(s)

The Colorado Team had the benefit of a statewide connectivity assessment to serve as the basis for the Corridor Design analysis. Linking Colorado’s Landscapes, completed in 2005, was a comprehensive effort to identify broad-scale movement corridors for Colorado wildlife through a process involving a series of expert workshops and computer modeling (Fig. 5). The project was conducted as a partnership between the Southern Rockies Ecosystem Project, the Colorado Department of Transportation, the Federal Highway Administration, the Nature Conservancy, and Colorado State University. This assessment resulted in the identification of 176 wildlife linkages across the state. These linkages – represented as coarse movement arrows – provided the analysis areas for linkage definition in the Corridor Design process.

GIS Mapping Step 2 – Compile List of Target Species

The Partnership Team identified a diverse set of target species to capture the range of ecological and topographic conditions present in the state, with the intention of creating a linkage design that would ensure their long-term viability. Target species met one or more of the following conditions: species identified as Tier 1 or Tier 2 species in the Colorado State Wildlife Action Plan (see box), species that are frequently involved in animal-vehicle collisions, and/or species of special management concern to CDOW (e.g., at-risk species, game species).

Figure 5: High priority linkages identified in Colorado’s statewide connectivity assessment. A total of 176 linkages were identified and prioritized across the state.
Figure 5: High priority linkages identified in Colorado’s statewide connectivity assessment. A total of 176 linkages were identified and prioritized across the state.
Target Species Justification
Bighorn sheep CSWAP Tier 2 species
Black bear Species of management concern
Black-tailed prairie dog CSWAP Tier 1 species
Boreal toad CSWAP Tier 1 species
Canada Lynx CSWAP Tier 1 species
Elk Species of management concern; AVC concern
Gray wolf CSWAP Tier 1 species
Gunnison’s prairie dog CSWAP Tier 1 species
Meadow jumping mouse CSWAP Tier 1 species
Mountain lion Species of management concern
Mule deer Species of management concern; AVC concern
Pronghorn Species of management concern; AVC concern
Swift fox CSWAP Tier 1 species
White-tailed prairie dog CSWAP Tier 1 species

Notably, there are several species that were identified as target species at the outset of the project, but were later removed from the list of target species being modeled. For example, meadow jumping mouse is a riparian species restricted to the Front Range of Colorado. Given its habitat is naturally linear and restriction to the riparian zone, linkages for this species cannot be mapped in the same manner as for other species. Instead, it is appropriate to highlight all suitable habitat for this species as a ‘conflict zone’ where special consideration for avoidance and mitigation measures is needed to adequately protect the species’ ability to move through its habitat. Similarly, species with small-scale movements, such as herpetofauna and some small mammals might operate at too fine of a scale to have their movement patterns adequately captured using this modeling process. In these cases, suitable habitat may be a better determinant of where avoidance or mitigation measures are needed. Attempts were made to model gray wolf and mountain lion, however, it was determined that the parameters for these species were too general to discern linkages between habitat core areas. To adequately model linkages for these species, other factors, such as prey availability, may be better suited for representing these species use of the landscape. Following is a list of species that were determined to be inappropriate for inclusion in the linkage design process:

Target Species Reason for Not Using Model Analysis to Identify Linkages Alternatives
Black-tailed prairie dog Movements too fine-scaled to model adequately Substitute all existing/potential habitat
Boreal toad Movements too fine-scaled to model adequately Substitute all suitable habitat
Gray wolf Habitat generalist – models poorly Consider using prey availability as a surrogate
Gunnison’s prairie dog Movements too fine-scaled to model adequately Substitute all existing/potential habitat
Meadow jumping mouse Movements too fine-scaled to model adequately Front Range riparian obligate – substitute all existing/potential habitat
Mountain lion Habitat generalist – models poorly Consider using prey availability as a surrogate
White-tailed prairie dog Movements too fine-scaled to model adequately Substitute all existing/potential habitat

GIS Mapping Step 3 – Define Habitat Parameters and Compile Data Layers
We used the following data layers to define each factor in the habitat suitability models:

Data Layer Data Source
Land Cover Southwest Regional GAP Analysis – 102 land cover categories
Elevation 30 meter resolution National Elevation Dataset (NED)
Topographic Position Created from the 30-m NED using the Create Topographical Position tool in Corridor Design
Distance to Roads Buffered distance (by species) from highways, major roads, local roads, and Forest Service roads

List of CDOW biologists Engaged in Model Parameterization:

Name Species Expertise
Jerry Apker Black bear, Canada lynx, Mountain lion
Janet George Bighorn sheep
Tina Jackson Boreal toad
Aaron Linstrom Pronghorn
Eric O’Dell Black-tailed prairie dog
Pam Schnurr Gunnison’s prairie dog
Scott Wait Bighorn sheep, Black bear, Canada lynx, Mountain lion
Bruce Watkins Bighorn sheep, Black bear, Canada lynx, Mountain lion

We found working with the species experts to define parameters for each of the target species to be one of the most time-consuming steps in the process, require significant review of the literature as well as one-on-one collaboration. We found that a number of biologists, being unfamiliar with GIS modeling concepts, were hesitant to provide definitive weights for the factors and factor categories as required to construct the models – there can be significant natural variability in activity and habitat use within a species, and in many cases these details are not well understood. Working with the individual biologists was an educational and iterative process for the Project Team, but was well worth the effort to ensure that the resulting species models accurately reflect habitat use.

Figure 6a: Elk linkage at Dallas Divide in southwestern Colorado crossing over Highway 62. Dark brown represents areas of low resistance (low cost of movement) between the two core habitat areas.
Figure 6a: Elk linkage at Dallas Divide in southwestern Colorado crossing over Highway 62. Dark brown represents areas of low resistance (low cost of movement) between the two core habitat areas.
Figure 6b: Lynx linkage crossing the same stretch of Highway 62. Note how the low cost (low resistance) portions of the linkage are significantly more restricted for lynx than they are for elk.
Figure 6b: Lynx linkage crossing the same stretch of Highway 62. Note how the low cost (low resistance) portions of the linkage are significantly more restricted for lynx than they are for elk.
Figure 6c: When unioned together, the details of the individual species linkages may be lost. We therefore recommend reviewing the individual species linkages both separately and combined for a given location for a more complete understanding of where mitigation efforts should be placed for the greatest benefit to multiple species.
Figure 6c: When unioned together, the details of the individual species linkages may be lost. We therefore recommend reviewing the individual species linkages both separately and combined for a given location for a more complete understanding of where mitigation efforts should be placed for the greatest benefit to multiple species.

GIS Mapping Step 5 – Biological review of species linkage models

For each target species, we conducted individual meetings with the species experts in which we thoroughly discussed the modeling process, explained each of the inputs into the model, and reviewed the resulting linkage maps. The purpose of these meetings was to evaluate the models and determine if any adjustments were needed to better represent species’ use of the landscape. Each reviewer then responded to the following questions:

  • Based on these results, are the input parameters appropriate for this species (including start/end points, factor weights and factor categorizations?)
  • Are there other factors that should be considered for this species? Such as prey availability, water sources, etc?
  • In the interest of keeping the model simple and straightforward, we did not categorize roads based on traffic volume. How does traffic volume influence movement for this species – should we differentiate among roads types with different traffic volume?
  • Look at how core areas are identified in the Corridor Design process and overlay this information with data on existing wildlife populations. Do core areas defined by the modeling process accurately reflect current population areas?

Questions to Ask

  • Does the State Wildlife Action Plan include data or maps for identifying conservation priorities and important habitat for species of conservation concern?
  • Be clear about the purpose of applying the Corridor Design analysis – what are you trying to connect? Why? Is this the appropriate tool for the job?
  • Does the suite of identified target species sufficiently represent the movement needs of native species in the analysis area?

Key to Success

  • Understand that many biologists are unfamiliar with GIS modeling, and may be hesitant to accept the modeling outcomes. Take the time to explain what the models represent and what they can and cannot do so that the species experts are better equipped to assist in defining habitat parameters.
  • Recognize that the one size may not fit all and that some species are not suited to a GIS modeling process.
  • Actively engage Division of Wildlife GIS staff in the modeling process.
  • Test modeling process through close collaboration with the species experts to fine tune the process and adjust parameters as needed.
  • Develop protocols to ensure that the linkage data is kept up to date. In general, such revisions are unlikely to be needed very frequently, as major changes and new insights into our understanding of a species habitat or habitat preferences are infrequent.
Step Three

Step Three: Develop Process for Early-Identification of Potential Wildlife Conflicts and Apply ‘Matchmaking’ System to Ensure that Mitigation is Placed Effectively

There is no one size fits all solution – every state DOT, and even different regions within the same state, undergo different processes in the development of a transportation project, and an early-warning flagging system must be designed within the context of that state’s project planning process. At this stage in the process, the team must determine the practical and technical aspects of integrating data layers on wildlife linkages into the project planning database and developing a system to alert planners and project managers to potential wildlife conflicts. This step requires the intensive participation of the Partnership Team, particularly those members that are engaged in various parts of the transportation planning and design process (i.e., planner, project manager, GIS staff, environmental clearance staff and a regional biologist).

Regardless of this variance in the planning processes, all states should consider the following points in determining an appropriate structure for an early-warning system:

  • Is the Statewide Transportation Improvement Plan (STIP), which outlines near-term (typically 3-5 years) project priorities and funding, available as a spatial data layer?
  • What is the framework for overlaying the STIP with wildlife linkages and other environmental data to identify potential conflict areas? Who is responsible for identifying these conflict areas and conveying wildlife needs to project designers at the outset of project development?
  • Once a transportation project has been flagged as intersecting with a wildlife core habitat or linkage area, what follow-up steps will be needed to develop and implement specific avoidance and mitigation measures to obtain the most functional and cost-effective solution for the diversity of species present in the project area?

Knowing where there are potential conflicts with wildlife habitat and movement areas is half the battle. The other half rests in developing effective mitigation measures and locating them in the best places. The FHWA-developed Eco-Logical approach proposes ecosystem-based mitigation as a means for “restoring and preserving habitat and other ecosystem feature in conjunction with or in advance of projects in areas where environmental needs and the potential environmental contributions are the greatest” (Brown 2006).

Eco-Logical – An Ecosystem Approach to Developing Infrastructure Projects (FHWA)

The matchmaking system is based on an assessment of the overlap between the Statewide Transportation Improvement Plan (STIP) of funded projects for the next five years and the mapped wildlife habitat and linkage areas. The purpose of this step is to provide a landscape-scale perspective in the evaluation of possible avoidance and mitigation measures to ensure that these measures are effective and compatible at the ecosystem level. This should include looking beyond the boundaries of a given transportation project to find the most effective mitigation sites. The matchmaking system provides a framework for proactively linking conservation priorities with mitigation needs to develop functional and cost-effective solutions.

In addition, project-level site assessments and collaboration with local wildlife agency staff further advances the consultation requirement as stipulated by Section 6001 in the 2005 Federal Highway Bill while advancing the goals of the State Wildlife Action Plan to minimize the threat of habitat fragmentation and restore connectivity.

Matchmaking: Considerations to Ensure Effective Placement of Mitigation

The following considerations should be evaluated to ensure that mitigation is placed in the most appropriate location. Conducting this assessment, as needed, early in the project planning process allows transportation agencies to meet mitigation requirements up-front, when they are both cheaper and easier to accomplish.

  1. Identify the full suite of species impacted and their associated habitat types,
  2. Assess the degree of conservation threat to the species of interest,
  3. Identify adjacent land ownership and protection status,
  4. Conduct a roadway engineering assessment to determine the feasibility of potential mitigations,
  5. Identify partners for collaboration on linkage protection and assess conservation opportunities,
  6. Assess the cost effectiveness of potential mitigations.

Colorado Case Study

The Colorado Partnership Team reviewed the planning process to determine where early consideration of these data would be most effective and appropriate. During these discussions, members of the team expressed concern about potential misinterpretation of the wildlife linkage data by non-biologists. In response, the Partnership Team agreed that within the DOT, the regional biologists would be the keepers of these data, and would be responsible for overlaying the linkage data with the STIP to highlight areas of overlap between planned transportation projects and wildlife movement zones (Fig 7). The biologists, in turn, would report areas with potential wildlife conflicts to planners, engineers and other participants involved in project design. The biologists would also use these data to focus their in-the-field assessments to identify specific mitigation measures. In this example, we found that in bypassing the larger database structure, we also bypassed numerous technical complications, ultimately facilitating the biologists’ consideration of wildlife linkage data early in the planning process.

In Colorado, the wildlife linkage data is a new line item of the checklist of environmental considerations that are reviewed when new transportation projects are being planned.

Figure 7: This overlay of a linkage model with the current STIP indicates that an upcoming transportation project across this entire linkage area.
Figure 7: This overlay of a linkage model with the current STIP indicates that an upcoming transportation project across this entire linkage area.

Prior to this project, wildlife connectivity needs were considered on an ad-hoc basis, depending on the awareness level of the individual CDOT biologist conducting the review, and their knowledge of wildlife movement areas for the array of species. This project removes the burden for each biologist to possess exhaustive knowledge of wildlife movement areas across the state, instead providing a comprehensive database of this information to complement their knowledge and expertise. These data cannot take the place of on-the-ground field surveys in the identification and placement of specific mitigation measures, but the linkage models will help to focus and guide these efforts, ultimately streamlining the process to improve landscape permeability for wildlife.


Colorado’s 2007-2009 Statewide Transportation Improvement Plan (STIP)
Colorado’s Wildlife Habitat and Linkage Planning Maps

 Questions to Ask

  • What is the process for updating the STIP and how frequently is it updated? How can the parties responsible for reviewing the overlap between the STIP and wildlife habitat and linkage areas be sure that they are reviewing the most up-to-date version of the STIP?
  • How do statewide transportation planners interact with regional planners?
  • Who at the transportation agency is best situated and has a satisfactory understanding of the data to be able to interpret them appropriately for planning and project design purposes to ensure that the best mitigation occurs in the best places?

 Key to Success 

  • Take the time to learn the steps involved in the transportation planning process, form long-range planning through project development – who is engaged at which stage, and who has access to which data. In Colorado, we found that there are a number of restrictions across departments in which data may be accessed and how it may be viewed. A clear understanding of these nuances is needed to ensure that wildlife linkage data can be made accessible to the right people at the right time.
  • While the modeled linkages are ‘spatially explicit’, we need to ensure that users do not assume that the boundaries are hard and fast, and that there is no wildlife movement over the roadway beyond these boundaries.
  • Be willing to adjust pre-conceived notions about what an early-warning system looks like to create a system that is best equipped to achieve the desired outcomes.
Next Steps

Next Steps and New Ideas in Designing and Implementing Mitigation Measures 

  • Encourage greater interagency coordination – develop a Memorandum of Understanding that outlines the processes for wildlife agency review of transportation projects, thereby facilitating collaborative efforts to minimize impacts from transportation projects and develop appropriate mitigation measures.
  • Based on these overlays of upcoming transportation projects and identified wildlife linkages, carry out targeted field visits to identify existing barriers to movement and the best locations for underpasses or overpasses these conflict zones. Invite local wildlife agency biologists to participate in these field visits and the design and placement of potential mitigations.
  • Develop guidelines to direct project managers and assist in biological review to support the mitigation development and design process. Guidelines should refer back to the State Wildlife Action Plan and alert the state wildlife agency to areas of potential conflict between transportation and wildlife linkage

Resources for Developing Guidelines:

Guidelines for Culvert Construction to Accommodate Fish and Wildlife Movement and Passage  (Arizona Game and Fish Department)

Guidelines and Criteria for Stream-Road Crossings (Oregon Department of Fish and Wildlife)

Massachusetts River and Stream Crossing Standards: Technical Guidelines (University of Massachusetts at Amherst, Natural Resources and Environmental Conservation)

Safe Passage (User’s guide to developing effective highway crossings for carnivores and other wildlife)

Wildlife and Roads (online decision-making tool to help mitigate roads for wildlife)

Brown, J. 2006. Eco-logical: An Ecosystem Approach to Developing Infrastructure Projects. Report No. FHWA-HEP-06-011. Federal Highway Administration.  Washington, D.C.Cramer, P.C., and J.A. Bissonette. 2007. Integrating wildlife crossings into transportation plans and projects in North America. Pages 328-334 in Proceedings of the International Conference on Ecology and Transportation. Little Rock, Arkansas.Ehrlich, P.R. 1986. The loss of diversity. Pages 21-27 in E.O. Wilson (ed). Biodiversity. National Academy Press, Washington, D.C.Forman, R.T.T. 2000. Estimate of the area affected ecologically by the road system in the United States. Conservation Biology 14:31-35.Forman, T. T. and R. D. Deblinger. 2000. The ecological road-effect zone of a Massachusetts suburban highway. Conservation Biology 14(1):36-46.Forman, R.T.T., D. Sperling, J.A. Bissonette, A.P. Clevenger, C.D. Cutshall, V.H. Dale, L. Fahrig, R. France, C.R. Goldman, K. Heanue, J.A. Jones, F.J. Swanson, T. Turrentine, and T.C. Winter. 2003. Road Ecology: Science and Solutions. Island Press, Washington, D.C.Gibeau, M.L. and K. Heuer. 1996. Effects of transportation corridors on large carnivores in the Bow River Valley, Alberta. In G.L. Evink, P. Garrett, D. Ziegler, and J. Berry (eds)  Trends In Addressing Transportation Related Wildlife Mortality.  Proceedings of the Transportation Related Wildlife Mortality Seminar.Harris, L.D. and P.B. Gallagher. 1989. New initiatives for wildlife conservation: the need for movement corridors. Pages 11-34 in, Defenders of Wildlife. In Defense of Wildlife: Preserving Communities and Corridors. Defenders of Wildlife, Washington, D.C.Maehr, D.S. 1984. Animal habitat isolation by roads and agricultural fields. BiologConservation 29:81-96.Noss, R.F. 1983. A regional landscape approach to maintain diversity. BioScience 33:700-706.Noss, R.F., and A.Y. Cooperrider. 1994. Saving Nature’s Legacy: Protecting and Restoring Biodiversity. Island Press: Washington, D.C.Reed, R.A, J. Johnson-Barnard, and W.L. Baker. 1996. Contribution of roads to forest fragmentation in the Rocky Mountains. Conservation Biology 10(4):1098-1106.White, P., J. Michalak, and J. Lerner. 2007. Linking Conservation and Transportation: Using the State Wildlife Action Plans to Protect Wildlife from Road Impacts. Defenders of Wildlife. Washington, D.C. 47pp.Wilcove, D.S., D. Rothstein, J. Dubow, A. Phillips, and E. Losos. 1998. Quantifying threats to imperiled species in the United States. BioScience 48:607-615.
Please contact Alison Gallensky at Rocky Mountain Wild for maps of this project.
Alison Gallensky
1536 Wynkoop St. Ste. 900
Denver, CO 80202