Habitat Connectivity

Washington State Department of Transportation (WSDOT) supports research on the relationships between wildlife and habitat and the transportation system. This includes statewide habitat connectivity analysis, ranking the suitability of existing bridges and culverts for providing wildlife passage, landscape permeability for large carnivores, and wildlife crossings and collisions analysis.

Learn how wildlife research contributes to the protection of fish, wildlife, and habitat resources during the operation of the state transportation system.

Statewide habitat connectivity analysis

The Washington Wildlife Connectivity Working Group (WWCWG) was established in 2007 to produce tools and analyses that identify and prioritize opportunities to provide habitat connectivity around the state. WSDOT and the Washington Department of Fish and Wildlife co-led the group.

In 2010, the WWCWG published a statewide analysis of habitat connectivity that identified areas around the state important for wildlife movements. WSDOT uses this information to establish priorities for investing in more wildlife-friendly highways. These investments include installation of roadside fencing, crossing structures, or a combination of the two.

Wildlife habitat connectivity considerations in fish barrier correction projects

WSDOT’s projects to correct barriers to fish migration present an opportunity to provide habitat connectivity for other species as well. WSDOT’s Fish and Wildlife Program’s Habitat Connectivity Investment Priorities GIS layers identify highway segments where there should be serious consideration of ways to improve wildlife passage at fish passage improvement locations. WSDOT project design teams use the Wildlife Habitat Connectivity Considerations in Fish Barrier correction projects guidance (pdf 690 kb) when designing fish passage structures. 

Ranking the suitability of existing bridges and culverts for providing wildlife passage

This WSDOT-funded research project developed a new method to rank the suitability of existing transportation structures for wildlife movement. This project used motion-triggered cameras to monitor wildlife use of bridges and culverts around the state. 

Use the links below to learn more about the project.

Black bear family using a WSDOT culvert.Bucks using a WSDOT culvert.Bobcat using a WSDOT culvert.

Landscape permeability for large carnivores 

The landscape permeability for large carnivores in Washington report (Singleton, Gaines, and Lehmkuhl) assesses wildlife movement using GIS weighted-distance and least-cost corridor analysis. Download the report and its maps and figures from the US Fish & Wildlife Services website.

Wildlife crossings and collisions

A lack of habitat connectivity can result in wildlife and vehicles on the roadway at the same time. Tracking wildlife killed on highways helps identify wildlife collision problem areas. This helps WSDOT look for ways to reduce collisions between wildlife and vehicles. Learn more about how WSDOT tracks and analyzes collision data by using the links below.

I-90 Snoqualmie Pass Wildlife Habitat Linkage Assessment report webpage 

This research assesses wildlife habitat connectivity and barriers to animal movement along 35 miles of I-90 in Washington state.

Analysis of Deer and Elk-Vehicle Collision Sites along State Highways in Washington State report webpage

This research analyzes the temporal and spatial relationships associated with wildlife collision sites.

Learn how WSDOT tracks the removal of wildlife carcasses from roadways and how to access the tracking data.