A number of states have completed statewide connectivity mapping to identify landscape-scale linkages connecting core habitat areas. The level of detail involved in mapping such linkages varies greatly from state to state. A few states, including Arizona and Florida, have conducted detailed modeling process from the outset of their linkage assessment processes. More typical is the example of states such as California and Colorado, where broad linkage arrows representing connections across the landscape were identified, but without defined spatial extents, or that of New Mexico and Utah, where stretches of highway with pronounced wildlife conflicts were identified, but without consideration for the broader landscape linkage. Such connectivity assessments are an important first step; however, without refined linkage modeling, these more limited connectivity assessments do not provide sufficient detail for application to project-level transportation planning, county planning, or land management issues. 

We sought to fill this gap in Colorado by using the statewide connectivity assessment as a starting point for conducting in-depth linkage modeling to give define spatial extents the identified wildlife linkages. We adapted the Corridor Design methodology – a freeware geographic information system (GIS) tool developed by researchers at Northern Arizona University – to assist with the design of identified high-priority linkages in Colorado. The ArcGIS tool encompasses a series of spatial analyses that walk the user through steps to define suitable habitat for target species, identify core areas, map the optimal corridors between core areas. Our team made several adjustments to the standard Corridor Design methodology to better address our needs and concerns. First, we used identified habitat core areas, such as production areas, for a given focal species rather than protected lands to help define the cores between which linkages were defined. Second we reconsidered how to define corridor width, opting to depict a broader linkage as a gradation representing the range of ‘costs’ for an animal moving across the landscape rather than limiting the corridor to minimum ‘biologically best corridor’. Finally, while the team strongly believes that mitigation strategies should be designed for the range of species present at a given mitigation location, we declined to union single-species linkages to create a single multi-species linkage at a given location. Instead, we encourage planners to review linkages both individually as well as overlaid with one another in the context of the planning environment. Instead of assuming that all portions of the linkage are equally important for all species considered in the linkage area, this process allows planners to assess the individual components of the linkage area on a species-by-species basis as well as derive a more complete understanding of where mitigation efforts can be placed for the greatest benefit to multiple species. 

This modeling effort resulted in spatially-explicit wildlife linkage data for seven species of greatest conservation need and other species of management concern to the Colorado Division of Wildlife now complete, these data can be overlaid with spatial data on upcoming transportation projects in the state’s transportation plan, county zoning maps, management prescriptions on public lands, and other applications. 

 These data have numerous applications in protecting and restoring habitat connections for wildlife, particularly as wildlife seek to adapt to climate changes and ecosystem shifts. Current applications for these data include, highlighting wildlife concerns in transportation project planning and design, including the I-70 reconstruction project; county-level zoning and transportation planning; and identifying areas of concern for the Western Governors’ Association’s Wildlife Corridors Initiative and the Western Renewable Energy Zones Initiative.