With few natural landscapes available in the country’s second-most-dense urban environment, San Francisco’s coyotes are shifting their diets — and doing so in different ways depending on their zip codes.
The number of restaurants and amount of pavement — or “impervious surfaces” — in a given San Francisco neighborhood are influencing what resident coyotes eat, according to a new study, published on Tuesday in Ecosphere.
Coyote consumption of rats was greatest where restaurant density was the highest, while consumption of human-sourced food was most common in the heaviest-paved parts of the city, the study authors found.
“Chicken is a really big diet item; we found it in 72 percent of the scat samples analyzed in the study,” lead author Tali Caspi, a PhD candidate at the University of California Davis, said in a statement.
After chicken was a natural coyote prey source — pocket gophers — present in about 57 percent of the 707 total scat samples, followed by human-sourced pigs, at 35 percent, and naturally-acquired racoons, at 16 percent.
Despite recent concerns about an increase in cat consumption, the scientists found feline remnants in only about 4.5 percent of the scat samples.
While coyotes have been longtime residents of San Francisco, they were driven out of the city in the beginning of the 20th century — only to return in the early 2000s, the authors noted.
“The city currently hosts a thriving coyote population, which regularly comes into conflict with urban residents,” they stated.
San Francisco, the researchers explained, is surrounded by water on the north, east and west and in the south is crossed by Insterstate-280: a freeway that has one of the highest roadkill numbers in the state.
“This study highlights the huge range of dietary and habitat affinities of coyotes as a species,” senior author Ben Sacks, director of the Mammalian Ecology and Conservation Unit at UC Davis, said in a statement.
Recognizing that this trait is already well-known, Sacks explained that the study goes further — providing evidence of the “relatively narrow proclivities of coyotes as individuals.”
“They tend to stick with what they know,” he said.
The researchers encouraged San Franciscans to share their spaces respectfully with their coyote neighbors, with the goal of reducing human-wildlife conflict. Such action, they explained, could include keeping cats indoors, not leaving pet food outside and disposing of waste securely.
The study authors expressed hope that their findings could help inform urban wildlife management strategies, which could prioritize the protection of native coyotes while minimizing human-wildlife tensions.
“There are a lot of different ways to survive city life as an animal,” Caspi said. “It speaks to the plasticity and resilience of these species to see all of these different strategies for coping with urban life.”
