Roadkill report: Bay Area motorists lead the state in hitting wild animals

Douglas Long collects data from a male black-tailed deer along CA state route 13 in Oakland, Calif on Saturday, Sept. 18, 2010 and includes his findings into the California Roadkill Observation System where anyone, including Long's fellow wildlife conservationists submit pictures and other information about roadkill sightings in California. In Oakland, Calif. on Saturday, Sept. 18, 2010. less Douglas Long collects data from a male black-tailed deer along CA state route 13 in Oakland, Calif on Saturday, Sept. 18, 2010 and includes his findings into the California Roadkill Observation System where ... more Photo: Kirsten Aguilar / The Chronicle 2010 Photo: Kirsten Aguilar / The Chronicle 2010 Image 1 of / 15 Caption Close Roadkill report: Bay Area motorists lead the state in hitting wild animals 1 / 15 Back to Gallery

The deer your daughter said jumped out of nowhere and dented the car she had borrowed to go out with friends might not be the elaborate fabrication it seems, a new analysis of highway crashes with animals would indicate.

Mule deer were involved in 88 percent of the 6,600 accidents involving wildlife and motor vehicles around the state last year, a tapestry of roadway carnage that is at a peak in the Bay Area, according to the annual report released Tuesday by the UC Davis Road Ecology Center.

The smashups also involved more bears and cougars among the myriad of creatures struck in California, where 12 motorists were also killed and 268 were injured in 2017, the report said. The roadway gore cost Californians hundreds of millions of dollars in damages.

“The bottom line is that most of the animals don’t have any natural adaptation to roadways and cars, so there is no instinct they can rely upon to avoid those collisions,” said Fraser Shilling, co-director of the Road Ecology Center. “These are fatal lessons, and most wildlife don’t go on to figure it out.”

Close to 3,000 of the 6,600 animals hit on the highways were killed, but Shilling said that’s only a fraction of the death toll. The calculations were based strictly on incident reports taken by the California Highway Patrol and the California Roadkill Observation System on state highways, which make up just 10 percent of the state’s paved roadways.

In addition, Shilling said many collisions are not reported or are only included in insurance claims, like the hypothetical roadway encounter between the daughter and the agitated deer. A great many animals just run off and die later, never to be found, he said. State Farm Insurance Co. said it gets about 23,000 customer claims a year for accidents involving wildlife.

What’s clear, though, is that the roadway bloodshed is getting worse.

The available data show that Californians spent $307 million on vehicle damage, emergency response, injuries, lost work and insurance associated with animal collisions in 2017. That’s an 11 percent increase over 2016. The $276 million spent on animal collisions in 2016 was itself a 20 percent increase from the year before.

From 2015 to 2017, there were 19,800 collisions with wildlife, according to the report.

What hasn’t changed over the years is the fact that motorists in the Bay Area plow into more furry critters than drivers in other parts of the state.

A 23-mile section of Interstate 280 between San Francisco and San Jose is the perennial top dog in the statewide competition for most roadkill, Shilling said. A 28-mile portion of Highway 101 in Marin County follows closely behind in the center’s calculations of animal blood spilled and damage caused.

The bloated and crushed corpses of furry four-leggers are also commonly found on State Route 13 in Alameda County, Highway 24 from Oakland to Walnut Creek, and Interstate 680 between San Jose and Fairfield.

The Sierra Nevada foothills, the North Coast, and parts of the Central and South Coast also contributed a prominent share to the slaughter, according to the report.

Besides the 12 people killed in accidents with wildlife across the state last year, 44 people suffered major injuries and 224 suffered minor injuries. Some 2,841 animals were killed in the accidents, and 149 had to be dispatched by emergency personnel. Nobody knows what happened to 2,119 animals that were hit by vehicles, the report stated.

Statewide, mule deer were hit more often than any other animal, followed by coyotes, black bears, wild pigs, mountain lions and elk.

Smaller animals, like squirrels and skunks, were not included in the overall analysis this year because they are less likely to pose a danger to drivers or cause damage to their vehicles.

Black bears saw the biggest increase in the number hit by cars, going from 89 in 2016 to 170 last year. Mountain lion collisions also went up, from 44 to 64.

“Predators are often at risk because they move around a lot (searching for prey). So it’s not surprising that you would get predators hit, (but) the fact that both of them went up might indicate that there is some ecological mechanism taking place,” Shilling said. “These are large animals. They will total your car.”

The problem, he said, is that the increase in the rate of wildlife-vehicle collisions has not been accompanied by a comparable increase in efforts to mitigate the problem.

Shilling said there is an urgent need for legislators to use state transportation funding to pay for fencing and construction of wildlife over-crossings on major highways. One such crossing, proposed to help mountain lions and other wildlife get over the Ventura Freeway at Liberty Canyon in the San Fernando Valley, would cost about $50 million, he said.

The Road Ecology Center has created an automated system tracking vehicle-wildlife conflicts on highways, a tool that he said could also be used in the future to help guide autonomous vehicles. It can be found at roadecology.ucdavis.edu/hotspots.

Peter Fimrite is a San Francisco Chronicle staff writer. Email: pfimrite@sfchronicle.com Twitter: @pfimrite