Wildlife habitat connectivity - Carcass removal

2022

WSDOT removes 40,968 wildlife carcasses from state highways from 2018-2022

From 2018 to 2022, WSDOT removed approximately 40,968 wildlife carcasses from state highways. Deer species accounted for about 54% (22,296) of the wildlife carcass removals recorded during this five-year period. Many animals involved in wildlife-vehicle collisions die outside of the right of way, so they may never be recorded. Multiple peer-reviewed studies suggest around three times as many collisions with large animals occur than are reported in carcass removal data.

Along with the nearly 22,300 deer, WSDOT recorded many lesser-seen animals, including 1,323 elk, 33 big horn sheep, 62 bobcats, 20 cougars and 81 moose in its five-year carcass removal counts. Birds are not exempt from vehicle collisions either as WSDOT removed 295 hawks and eagles, 610 owls and 683 other birds from roadways from 2018-2022.

In addition to the life-and-death circumstances of these collisions, each carcass removal represents an economic impact. According to a 2009 study (adjusted to 2023 dollars), the average economic impact of wildlife-vehicle collisions is:

• Deer, $9,867 per collision
• Elk, $26,070 per collision
• Moose, $45,868 per collision

WSDOT uses carcass data to identify wildlife-vehicle collision hotspots

WSDOT collects data when a wildlife carcass is removed from the roadway. Wildlife carcass removals are considered the results of wildlife-vehicle collisions. In 2016, Washington established a law allowing citizens to collect deer and elk killed by vehicles for consumption, as long as a free permit is obtained (these are called citizen salvages). This information is incorporated into the carcass removal data.

WSDOT uses carcass data to identify wildlife-vehicle collision hotspots and determine high priority locations at which to invest limited resources to benefit wildlife connectivity. Providing wildlife crossing structures and wildlife barrier fencing is the best way to reduce collisions and increase habitat connectivity.

2021

WSDOT uses carcass data to identify wildlife-vehicle collision hotspots

WSDOT collects data when a wildlife carcass is removed from the roadway. Wildlife carcass removals are considered the results of wildlife vehicle collisions.

WSDOT uses this data, which it has collected since 1973, to identify wildlife-vehicle collision hotspots and determine high priority locations in which to invest limited resources to benefit wildlife connectivity. Providing wildlife crossing structures and wildlife barrier fencing is the best way to reduce collisions and increase habitat connectivity.

From 2017 to 2021, WSDOT removed 41,151 wildlife carcasses from state highways. Deer species accounted for about 56% (23,207) of the wildlife carcass removals recorded during this five year period. Many animals involved in wildlife-vehicle collisions die outside of the right of way, so they may never be recorded. Multiple peer-reviewed studies suggest around three times as many collisions with large animals occur than are reported in carcass removal data.

In addition to the life and death circumstances of these collisions, each carcass removal has an economic impact. According to a 2007 study (adjusted to 2022 dollars), the average economic impact of wildlife-vehicle collisions is:

• Deer, $9,175 per collision
• Elk, $24,242 per collision
• Moose, $42,652 per collision