Once coyotes get a taste for city living, the call of the wild fades to a whisper. Food is abundant and predators are few. Research indicates that coyotes enjoy the benefits of urban areas enough to put up with all the people, and Seattle is no exception.
Over the past century, coyotes have colonized every major metropolitan area in North America. Chicago is home to an , and in Los Angeles, urban coyote density is at least seven times higher than in wild areas. Coyotes are often spotted in parks and neighborhoods , but the lack of formal data makes it difficult for researchers to track trends.
鈥淲e observed a ninefold increase in coyote density in Seattle compared to more natural and wild areas of the state,鈥� said lead author , a UW professor of environmental and forest sciences. 鈥淭hat might surprise people who think of coyotes as afraid of humans, but I think it just shows how ideal the urban setting is for coyotes.鈥�
The results in Environmental Research: Ecology.
In the study, researchers analyzed coyote scats collected throughout Seattle and from wild study areas near Winthrop in north-central Washington and Chewelah in the northeastern part of the state. They estimated density based on how often they picked up a scat from the same animal, identifying 261 total coyotes from 842 scats.
Researchers were also curious about factors that influence density within the city, such as the luxury effect 鈥� where wealthier neighborhoods have more plant and animal diversity. Researchers compared the coyote density maps to ones showing pollution level, tree cover, buildings and roads, human population density and income level. Of those factors, only human density seemed to influence the coyotes.
鈥淚n Seattle, human population density had a negative effect on coyote density. But when you compare coyote abundance in Seattle to areas with far fewer people, the coyote population was much higher in the city,鈥� Prugh said.
Although coyotes are wary of people, the conditions that dense human populations create favor their survival. Urban coyotes are less likely to be killed or go hungry than their wild counterparts.
that fear of mortality may play a role in determining where coyotes live. In the wild, larger carnivores such as wolves and mountain lions hunt coyotes, but in cities they get to masquerade as apex predators. Farmers and landowners are also more likely to kill coyotes to protect their livestock in rural settings.
The only things that regularly kill urban coyotes are cars and disease.
Cities also offer a wider variety of food options for coyotes. Scat analyses showed that urban coyotes鈥� diets were more than twice as diverse as those of wild coyotes, although .
Rabbits are the choice prey for coyotes in most ecosystems and the abundance of one often impacts the other. Seattle鈥檚 over the past few decades changed urban ecology, and may have helped draw coyotes to the region.
鈥淐oyotes and rabbits have a natural relationship, even in a highly altered environment like Seattle,鈥� Prugh said. Rabbit density could be an even stronger predictor of coyotes than humans, she added, but there isn鈥檛 enough data to test the theory.
Although long-term coyote population data is also limited, there is overwhelming anecdotal evidence of coyote abundance increasing in the past few decades, Prugh said.
Sightings are more common at dusk and dawn, but coyotes are now as well. They tend to avoid people, but residents have raised concerns about coyotes and displaying territorial or behavior.
Because they are territorial, coyotes will fight each other over turf. This behavior helps control their population in the absence of other predators. Cities can only support so many coyotes, but Prugh isn鈥檛 sure whether Seattle has met that limit yet.
Either way, the coyotes aren鈥檛 going anywhere fast.
鈥淥ne thing that coyotes have shown over and over is that they are incredibly resistant to control efforts,鈥� said Prugh. 鈥淲ith enough food, they will just have more pups.鈥�
The study also highlights some of the often overlooked ways that coyotes can benefit the ecosystem. For example, by munching on young plants, and coyotes help them by munching on rabbits.
鈥淲hether there are too many or too few coyotes is sort of a societal question, but ultimately our answer might not matter,鈥� said Prugh. 鈥淐oyotes are here to stay in cities, and it is up to us to learn how to live with them.鈥�
Co-authors include , lab manager at the UW; of Purdue University; and of Colorado State University; of the Wildlife Institute of India; of New Mexico State University; and of the University of California Berkeley.
This research was funded by the U.S. National Science Foundation, the UW Royalty Research Fund, the Woodland Park Zoo, the Animal Welfare Institute and the Fulbright India program.
For more information, contact Prugh at lprugh@uw.edu.