Work starts this month on the Wallis Annenberg Wildlife Crossing. Last year, the Annenberg Foundation sponsored the largest spanning overpass of its kind - 210 feet over ten lanes of the 101 Freeway at Liberty Canyon to the tune of $25 million donated to the National Wildlife Federation's #SaveLACougars campaign.
So far campaign donations from 4,867 donors total $74,331,764.60 of the $85,000,000 goal.
Before the explosion of automobiles to transport two, or more car families to and from work, wild animals had a better chance of surviving their expeditions to find food and a mate from a different gene pool.
People in the United States depend on cars — 91% of adults commute to work using personal vehicles, and cars provide a level of convenience that is often unmatched by other transportation modes. Moody, J., Farr, E., Papagelis, M. et al.
Human transport infrastructure location, design, and construction previously paid little attention to existing natural wild animal routes. Highways go from A to B with no concern for big (or small) wildlife, Florida (or Californian) mountain lions, or Costa Rican sloths.
Seventy-eight old-growth redwood forest trees in the way of a freeway widening? No problem, be careful with the roots, remove thirty-eight new-growth trees, and make it wide enough for larger trucks to use Highway 101. At the cost of $21 million to taxpayers and saving a 93-mile detour for truckers.
Since 2010 the number of cars in the US has increased from 24.7 million to 289.5 million. From 2010 to 2020, the population grew by 22.7 million. According to the US Census Bureau, the total US population was 331.4 million; 258.3 million were adults 18 years or older — a 10.1% increase from 234.6 million in 2010.
Federal Highway Administration and Technology reported an estimated cost of $8,388,000,000 per year for WVCs in 2008.
According to Reducing Wildlife Vehicle Collisions by Building Crossings, commissioned by The Pew Charitable Trusts, Californian all large wildlife vehicle collisions (WVC) total annual cost estimate for 2018 was $232 million (figure provided by researchers). The study found that some states only report the cost of significant damage, injuries, and fatalities. Other states collect data on the number of carcasses removed by their employees. Motor vehicle insurance companies also provide claim records.
When combined with wildlife fencing to keep animals off the road and funnel them towards the structures, wildlife crossings have consistently resulted in >80% reductions in WVCs. Pew Trusts
Florida Fish and Wildlife Conservation Commission figures from 1981 to 1999 show four or fewer panthers died in road collisions per year. But from 2000, kills increased to between six and thirty-four per year.
Steps were taken to reduce collisions, such as reduced speed limits at night, reflectors to shine headlights towards panthers, and widening road shoulders to increase visibility helped but did not stop the problem.
“Ten years ago, wildlife bridges were experimental. We didn’t know whether they would work or not. Now they’ve shown they get huge reductions in collisions. In some cases, 85% to 99% reductions,” Rob Ament, a road ecology expert at Montana State University.
With its chain-link fences and underpasses, the new motorway running through Florida's Everglades now saves alligators, cougars, and bears from becoming injured or roadkill. Of course, the cost of collisions to human life and insurance companies must also be considered.
"...it actually costs society less to solve the problem of WVCs than it costs to do nothing. Pew researchers." Pew researchers.
Enlarging underground drainage pipes and overground bridges allows wildlife to pass safely along wetlands and through pipes or under/over bridges to fresh habitats and diverse mating possibilities.
Human infrastructure benefits of wildlife crossings include greater resilience to climate change and extreme weather, e.g., flooding. And saves taxpayers money.
Conservationists solved the Florida panthers' problem by importing eight females from Texas. Numbers went up from a couple of dozen to a population of around 200 mountain lions.
Santa Monica's mountain lions experienced the same lack of fresh mates and thus genetic diversity, but Californian conservationists decided a wildlife bridge would be the answer. They identified Liberty Canyon as the optimum point to allow the mountain lions easy access between Santa Monica Mountains and the Sierra Madre Range. The bridge will link two mountain lion groups, provide shared habitats, and support ecological and evolutionary processes.
Completion of the Wallis Annenberg Wildlife Crossing is expected to be in October 2023, as reported by the LA Times recently in Caltrans to start on wildlife bridge on 101 Freeway in January.