Once regarded as a symbol of the American West, the coyote has been quietly moving east since the early 20th century. In recent decades, it has colonized such far-flung places as Cape Cod, and in 1999 one was captured in New York City's Central Park.
The sprawling suburbs of the East, which represent a kind of last frontier for the coyote, have been especially hospitable, ecologically speaking. Coyotes do well in habitat where wooded and cleared areas merge, and suburban settings can be rife with prey such as deer and small mammals.
Although it is now ubiquitous in the United States, the coyote, like many larger predators, remains a mystery to many people, and it has been much maligned, usually out of ignorance. Matthew Gompper, assistant professor of mammalogy at the University of Missouri and an ecologist specializing in carnivores, has been studying coyote population biology in the Northeast. Here, he sorts coyote fact from fiction.
NG News: Is it true that coyotes are larger in the East?
Gompper: They are somewhat larger than the coyotes of the Great Plains and the Southwest.
And coyotes of the Northeast are the largest of all?
Coyotes in the Northeast have been stereotyped as huge. They're larger than coyotes elsewhere, but that's typical of a lot of species, such as bears. This is known as a latitudinal cline—as you go north, animals get larger. Once you factor that in, it's not clear that coyotes of the Northeast are exceptionally large. Actually, there are no standout differences among coyote populations across the range of the species.
How large do coyotes get in the Northeast?
A 40-pound (18-kilogram) individual would be very large. In the Adirondacks, where some of the largest coyotes in North America exist, the average male weighs nearly 40 pounds; the average female, 31 pounds (14 kilograms). Elsewhere in the Northeast, average weights range from 31 to 35 pounds (14 to 16 kilograms), and in the Midwest the range is 24 to 31 pounds (11 to 14 kilograms). These aren't big differences. No coyote anywhere comes close to reaching the massive proportions of a gray wolf. The coyote is far smaller than the typical German shepherd.
Why did the coyote's range expand east?
The coyote probably originated in the Great Plains, so it's a species that thrives in open country. At the turn of the 20th century, it began to take advantage of new habitat that agriculture and logging had created. It also benefited from the decline of the gray wolf, a competitor and a predator of the coyote. There were two main waves of colonization, northern and southern. The northern wave occurred first—the coyote showed up in northern New York in the late 1930s. Most of the southeast wasn't colonized until the 1960s.
Had the coyote previously existed in the East? Was it returning to areas in which it had been wiped out?
There isn't strong evidence to support the view that the coyote once existed in the East, then disappeared, and has now returned. It's plausible that a coyote-like animal did inhabit the Northeast during the Pleistocene.
Is it true that coyotes have even colonized offshore islands?
Yes. They're good swimmers. In the Northeast, for example, they've colonized the Elizabeth Islands of Massachusetts.
As coyotes spread east, did they hybridize with wolves?
There's good data to suggest that coyotes hybridized with wolves in the past. As coyotes expanded into the Northeast, for example, they may have hybridized with remnant populations of wolves, most likely in Canada. Some, therefore, might have a proportion of wolf DNA in their genome. But the significance of this isn't clear. These animals clearly act like coyotes and not wolves.
What about hybridization with domestic dogs?
Coyotes hybridize with dogs, but this is very rare in the wild, where they have plenty of opportunity to mate with members of their own species.
How big is the coyote's territory?
Home ranges are smaller in agricultural and suburban areas, because there's more prey. A coyote living in an Adirondack forest could have a territory as large as 62 square miles (100 square kilometers), while a suburban coyote could do fine with one-fifth that size, perhaps less. The suburb's patchwork of wooded and open areas offers an abundance of edge habitat, which the coyote is highly adept at exploiting.
Which prey animals do coyotes seem to prefer?
Rabbits and deer make up most of their diet in the Northeast, but they will take pretty much any animal that comes their way, if they can overpower it. They also eat carrion and a fair amount of berries—in late summer, blueberries and raspberries may constitute half their diet. Most of their predation of deer is on fawns, although several members of a pack could bring down an adult.
Do they prey on domestic cats?
Coyotes are opportunistic predators. There's no evidence that individuals specialize in hunting domestic cats, but we know coyotes will eat cats as well as small dogs. We don't know whether these animals are a significant part of their diet. Of course, from the perspective of pet owners, coyotes are a danger. Predation of smaller livestock is also a valid concern.
Do coyotes pose a danger to humans?
Almost all attacks on people seem to represent an attempt to gain or to defend a food resource. In the Northeast, I'm aware of five or six such attacks. In some cases, the coyotes were getting handouts or were feeding at dumps, so they were habituated to humans and associated them with food. Other cases involved hunters. Hunters track wounded animals, and so do coyotes, which makes the two more likely to meet. Instances of coyotes viewing humans as prey are extremely rare. In 1998, a coyote attacked a three-year-old boy on Cape Cod. I've seen no conclusive evidence that the coyote was being fed, so this may have been one of the few cases of true predation directed at humans.
Do coyotes ever form large packs?
Sometimes. A large pack would include a mated pair with multiple generations of young. But small family groups—a pair with their most recent offspring, accompanied by yearlings that have yet to strike out and find their own territories—are more common. When hunting, packs may break into subgroups of two or three individuals. Solitary individuals old enough to be on their own but too inexperienced to secure a territory are known as floaters.
Will the coyote's presence in the suburbs reduce populations of "problem species" such as white-tailed deer and Canada geese?
During harsh winters, predators such as coyotes can significantly reduce deer herds, but I'm not aware of anyone who has studied the dynamics of coyotes and white-tailed deer in suburban environments. Since coyotes have only recently arrived in eastern suburbs, we know little about their natural history there. Once researchers have time to study them, we'll be able to make informed comparisons with what has occurred in the West, where coyotes have very different prey and competitors. As for Canada geese, coyotes do prey on waterfowl, but again, studies of this particular dynamic are lacking.
What's the coyote's future in the suburbs of the East?
They will increase until resources are unable to support further growth. Then, their population will level off.
What would you say to suburbanites who feel uncomfortable about having coyotes as neighbors?
Coyotes are far less of a threat than the dog next door. I think a person who sees a coyote should feel lucky. Coyotes are most active at night, at dawn, and at dusk; they avoid humans; and they're often mistaken for dogs. So, even though they inhabit areas of high human density, they're pretty much invisible.