San Francisco coyotes change their roster: study

With less available landscape in the nation’s second-dense urban environment, San Francisco’s coyotes are changing their diet — and doing so in different ways depending on their zip codes.

The number of restaurants and the amount of sidewalk — or “impervious surfaces” — in a San Francisco neighborhood affect what resident coyotes eat, according to a new study published Tuesday in the journal Ecosphere.

The study authors found that coyote consumption of mice was greatest where restaurant density was highest, while human-sourced food consumption was more common in more paved parts of the city.

“Chicken is a really macronutrient. We found this in 72 percent of the stool samples analyzed in the study,” lead author Tali Caspi, a doctoral candidate at UC Davis, said in a statement.

After all, chickens were a natural source of coyotes’ prey – pocket gophers – present in about 57 percent of the 707 total droppings sampled, followed by human-sourced pigs at 35 percent, and naturally acquired raccoons at 16 percent.

Despite recent concerns about increased cat consumption, scientists have found cat remains in only about 4.5% of fecal samples.

Although coyotes have been long-time residents of San Francisco, they were driven out of the city at 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.

The researchers explained that San Francisco is surrounded by water to the north, east and west, and in the south it is crossed by Insterstate-280: a highway that has one of the highest rates of road murder in the state.

“This study highlights a wide range of nutritional and habitat correlates of coyotes as a species,” lead researcher Ben Sacks, director of the Mammal Ecology and Conservation Unit at UC Davis, said in a statement.

Recognizing that this trait is already well known, Sachs explained that the study goes further—providing evidence of “the relatively narrow tendencies of wolves as individuals.”

“They tend to stick to what they know,” he said.

Researchers encouraged San Francisco residents to respectfully share their space with their wolf neighbors, with the goal of reducing human-wildlife conflict. They explained that such a measure could include keeping cats indoors, not leaving pet food outside and disposing of waste safely.

The study’s authors expressed hope that their findings could help inform urban wildlife management strategies, which could prioritize the protection of native coyotes while reducing human-wildlife tensions.

“There are a lot of different ways to survive city life as an animal,” Caspi said. “It speaks to the resilience and resilience of these species to see all these different strategies for dealing with urban life.”