Urban coyotes have developed a taste for human food

The clever coyotes of San Francisco are proving just how adaptable they can be to urban life.

These native predators, who returned to the city in the early 2000s after a century-long absence, aren’t just surviving in the concrete jungle – they’re thriving. The coyotes have learned to switch up their menu based on what each neighborhood has to offer.

Scientists from the University of California, Davis, recently conducted a study to better understand how these animals are adapting to urban life.

The findings reveal how restaurant density, pavement levels, and other urban features influence what coyotes eat.

Urban coyotes’ diets are changing

Urban environments present new challenges and opportunities for wildlife. As green spaces shrink, coyotes in San Francisco are forced to modify their food sources.

The researchers found that these adaptable predators consume a significant amount of human-provided food. “Chicken is a really big diet item; we found it in 72% of the scat samples analyzed in the study,” noted lead author Tali Caspi, a Ph.D. candidate at UC Davis.

Despite their reliance on human food, coyotes still hunt natural prey when available. Pocket gophers, a common rodent in the area, were the second most frequent food source, found in 57% of scat samples.

Other notable items in their diet included pig (human-sourced) and raccoon (natural prey).

While concerns about coyotes hunting domestic cats exist, the study showed that feline remains appeared in only 4.5% of analyzed samples. This suggests that predation on pet cats is not a significant part of their diet.

Investigating urban coyote diets

To uncover these dietary patterns, the researchers collected more than 700 coyote scat samples from different parts of San Francisco between September 2019 and April 2022.

The team analyzed the samples at UC Davis’ Veterinary Genetics Laboratory, using genotyping to match scat to individual coyotes and DNA metabarcoding to determine what they had eaten.

One key finding was that urban coyotes living in areas with high restaurant density, such as downtown and other heavily paved neighborhoods, consumed more human food.

In contrast, those living in greener areas, such as the Presidio or Golden Gate Park, relied more on natural prey. This variation highlights how coyotes adapt their foraging behavior based on their surroundings.

The study also revealed that while individual coyotes within the same family had similar diets, the diets of different family groups varied significantly.

“This study highlights the huge range of dietary and habitat affinities of coyotes as a species. That is a trait for which they are already well-known, but the study also joins a growing body of evidence pointing to relatively narrow proclivities of coyotes as individuals. They tend to stick with what they know,” noted senior author Ben Sacks, director of the Mammalian Ecology and Conservation Unit at UC Davis.

Return of coyotes to San Francisco

Coyotes are native to San Francisco, but they were eradicated from the city in the early 1900s. For nearly a century, they were absent from the urban landscape.

However, in the early 2000s, coyotes made a comeback and have since established a stable population in the urban areas.

Today, they share space with more than 870,000 people in a city that spans just 47 square miles, making San Francisco the second-most densely populated major city in the United States.

Despite their return, many people remain unaware of how to coexist with these animals. Coyotes are opportunistic feeders, meaning they take advantage of whatever food is easiest to access.

While they can hunt naturally, human-provided food – whether intentionally given or found in trash – has become a major part of their diet.

Coexisting with urban coyotes

As coyotes continue to thrive in San Francisco, it is important for residents to take steps to reduce conflicts.

Many conflicts arise when people inadvertently provide food, either by leaving pet food outside, improperly disposing of trash, or feeding them directly. This can make coyotes more comfortable around humans, increasing the chances of unwanted encounters.

“There’s a misconception that coyotes are starving and need our help finding food in San Francisco, and clearly they don’t,” noted Caspi.

In reality, coyotes are highly adaptable and capable of surviving without human intervention.

Another way to minimize conflicts is by keeping domestic pets safe. Coyotes may not actively hunt cats, but they are opportunistic predators. Keeping cats indoors and ensuring that small pets are supervised can help reduce negative interactions.

Urban wildlife and adaptation

San Francisco’s urban coyotes are part of a larger trend of wildlife adapting to city life. Around the world, animals are learning new ways to survive in urban environments.

Song sparrows in Portland, Oregon, adjust their song frequencies to be heard over city noise, while cockatoos in Australia have figured out how to open trash cans for food. These behaviors demonstrate how different species develop unique survival strategies when faced with human-made landscapes.

“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.”

Coyotes, known for their intelligence and adaptability, are no exception. They have successfully integrated into one of the country’s most densely populated cities, using their keen instincts to navigate an environment vastly different from their historical range.

Future of coyotes in San Francisco

The study’s findings provide valuable insights into urban wildlife management. By understanding what coyotes eat and how they adapt to their environment, city officials and conservationists can implement better strategies to reduce conflicts while protecting both wildlife and human residents.

The research was funded by a Christine Stevens Wildlife Award from the Animal Welfare Institute, along with support from UC Davis, UC Berkeley, and the UC Davis Center for Community and Citizen Science.

Contributions from community scientists via iNaturalist also played a crucial role in the study, helping researchers locate fresh scat samples and even leading to a rare discovery of fin whale DNA in a coyote’s diet. This was traced back to a beached whale recorded on the app.

As San Francisco continues to evolve, so will its urban coyotes. They have proven their ability to adapt, and their presence in the city is likely to remain a fixture of the urban ecosystem. Learning to coexist with them will be essential in maintaining a balance between wildlife conservation and city life.

The study is published in the journal Ecosphere.

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