Maine Terrestrial Wildlife Crossings Survey Report: Potential for Retrofitting Transportation Infrastructure to Benefit Movement of Terrestrial Wildlife
Barbara Charry, Julia Kintsch - 2015
Organization: Maine Audubon
Roads and associated traffic act as deterrents or barriers to movement between habitats of many terrestrial wildlife species. When wildlife cross roads, they are at risk of getting killed by vehicles and these collisions can be a safety issue for people too. Mortality from wildlife-vehicle collisions can reduce wildlife populations and for some sensitive species, exacerbate the threat of extinction. Wildlife must move to meet their daily life needs, to breed, and to disperse to new territories. Their ability to move and access necessary habitats will be even more urgent in the future as habitats shift across the landscape due to a changing climate.
Wildlife road crossings are a proven solution to help wildlife safely cross roads and prevent collisions with the traveling public. Identifying which sites are top priorities for building wildlife road crossings is important to best meet the needs of wildlife and use limited funding most effectively. Retrofitting culverts and bridges that are already in place is a cost effective approach for improving wildlife passage under roads. Where there are no dedicated wildlife crossing structures, retrofitting existing road structures can provide opportunities for wildlife to move safely between habitats, and improve permeability for wildlife along road segments. Retrofits can also be used to provide additional opportunities for wildlife to move complementing crossing structures built specifically for wildlife.
During the summer and fall of 2014, Maine Audubon and its partners — the Maine Department of Transportation, Maine Department of Inland Fisheries and Wildlife, and The Nature Conservancy — conducted a pilot project to survey and evaluate existing road crossings for retrofit potential. This project used the “Permeability of Existing Structures for Terrestrial Wildlife: A Passage Assessment System (PAS)” developed for the Washington State Department of Transportation in cooperation with the U.S. Department of Transportation, Federal Highway Administration (Kintsch and Cramer 2011).
Document Type: pre-mitigation protocols
pre-mitigation monitoring guidelines
mitigation monitoring results
justification to mitigate
Project Type: underpass
Infrastructure Asset: existing roadway