A study published Thursday finds that roadkill rates in three states declined with traffic reduced from stay-at-home orders to help fight COVID-19.
Researchers at the Road Ecology Center at the University of California Davis used traffic and collision data and found that the number of animals killed on roads by cars declined by 21-56% in California, Idaho and Maine from early March to mid-April.
"There is a statistically significant decline in wildlife deaths on highways in all three states following reductions in traffic this spring,” said Fraser Shilling, director of the UC Davis Road Ecology Center and report author, in a news release.
“This has not been the case for any of the previous five years for these three states. If anything, there is usually an increase in spring” Shilling said.
California was the first state in the country to issue a stay-at-home order on March 19 to address the coronavirus. From early March to mid-April, traffic reduced by 71% in the state, according to the study.
More than 8 large animals were killed daily by vehicles in California before stay-at-home orders. That number dropped to 6.6 after the order was issued. Mountain lion deaths, in particular, declined by 58%.
Some researchers have predicted that in Southern California mountain lions could go extinct within 50 years.
In April, the state's Fish and Game Commission voted unanimously to include mountain lions in Southern California temporary protection under the Endangered Species Act meanwhile officials review a petition filed by environmentalists to list the big cats as endangered species.
According to the study, there are three main threats to the mountain lions: state-permitted killing of mountain lions that may have attacked domestic animals; mortality from road and highway traffic; and population fragmentation by busy highways.
“The reduction in numbers of wildlife killed is surprising, and is a silver lining for both wildlife and people at this difficult time,” said Winston Vickers, who directs the California Mountain Lion Project, in a statement.
“For Southern California mountain lions, even one lion making it across a road instead of being killed can be very significant for populations like the ones in the Santa Monica or Santa Ana mountain ranges.”
In Idaho, the stay-at-home order was issued March 25. Traffic dropped by 63% from early March to mid-April, and the number of animals killed on roads dropped by 38%.
The stay-at-home order in Maine was issued on March 31, and traffic also decreased by 73% during the study period. The number of large animals killed daily on roads reduced by nearly half.
While the number of roadkill rates have declined in recent months, all 50 states have eased coronavirus restrictions and have started to reopen their economies. Summer travel is expected to be down 15% from last year, but AAA still projects 683 million road trips from July to September, which could spread the coronavirus.
Dr. Anthony Fauci, the top infectious disease expert at the National Institutes of Health, told Congress Tuesday that the next two weeks will be "critical" in how the country addresses the surge in states like Florida, Texas and Arizona.
Contributing: Adrianna Rodriguez and Karen Weintraub, USA TODAY; Cheri Carlson, Ventura County Star