National Park Service says (opens in new tab)<\/a> coyote families maintain territories that \u201ccan span several miles.\u201d\u00a0<\/p>\nAidan Moore, who works for Alcatraz City Cruises, said the coyote has been holed up near the parade grounds, where birds frequently nest. Bird carcasses have recently been found around the island, Moore said.<\/p>\n
\u201cHe\u2019s certainly much fatter than when he arrived,\u201d said Moore. \u201cWe don\u2019t know how long he\u2019s going to be a resident here, because if he interferes with the nesting birds he might get relocated to the mainland.\u201d<\/p>\n
It is the first documented coyote on Alcatraz since the island was transferred to the National Park Service in 1972.<\/p>\n
\u201cPark biologists and staff are actively monitoring the coyote to better understand how it is surviving on the island and to assess any potential impacts to the seabird breeding colony,\u201d the NPS said in a statement.<\/p>\n
Kessler urged the agency to let the coyote remain on Alcatraz.<\/p>\n
\u201cHe expended a huge amount of effort to reach the island,\u201d Kessler wrote on social media. \u201cIf he can survive there, we should allow him to.\u201d<\/p>\n
Kessler and a UC Berkeley researcher said the coyote likely left the mainland due to territorial pressure from the city\u2019s approximately 20 coyote family groups, each of which defends its turf against outsiders. With limited options for dispersing young coyotes \u2014 about 30 are killed by cars in San Francisco each year \u2014 this one apparently decided to strike out across the water.<\/p>\n
Christopher Schell, an assistant professor at UC Berkeley who studies how carnivores adapt to urban environments, said coyotes rarely display this type of swimming endurance, but it\u2019s not unprecedented. He recalled reports of coyotes swimming up to three miles to islands from Seattle and Tacoma, Washington.<\/p>\n
\u201cWe\u2019re just now coming to the realization of their swimming and navigation prowess,\u201d he said.<\/p>\n
Schell said the coyote\u2019s successful crossing likely reflects intense competition for territory on the San Francisco Peninsula. Research conducted by his lab, in collaboration with Kessler, the California Academy of Sciences, UC Davis, and community science groups, has confirmed that the area is saturated with coyotes.<\/p>\n
\u201cHigh territoriality and competition may have pressured the animal to seek new opportunities or open niches that could have resources to sustain a population,\u201d Schell said. \u201cThe gamble was likely made because competition on the peninsula was too stiff.\u201d<\/p>\n
He said a hands-off approach could allow the coyote to help regulate prey populations on the island, potentially increasing biological diversity.<\/p>\n
But if it must be relocated, Schell said, authorities should consider if the animal could survive a move without hurting its health, then establish a viable domain elsewhere and avoid conflict with humans.<\/p>\n
\u201cThat animal may be just as likely to get hit by a car if it is relocated, as it tries to cross a road that is unfamiliar,\u201d he said.\u00a0<\/p>\n
\u201cThey have been able to successfully colonize so many different types of urban environments, habitats, and biomes across the North American continent that it is no surprise that one of their superpowers is also being able to have the necessary nautical navigation skills and stamina to successfully swim to nearby islands,\u201d he added. \u201cWe still have a lot to learn about coyote flexibility, social ecology, and their intersections with the urban interface.\u201d<\/p>\n