Eastern coyotes big enough to take down deer
Some deer hunters in the Northeast like to point fingers at the coyote as a reason behind anecdotally determined population downturns in the white-tailed population, all the while looking beyond human factors like habitat destruction, pollution and road-building.
(Even a casual out-of-doors person knows well, however, that many deer are roaming around.)
Hoofprints in the mud, road-killed individuals, and browse lines are some of the well-known indicators of a numerically large deer herd. I counted dozen-plus deer carcasses along eastbound Interstate 80 while returning home from State College on Thursday.
But let’s take a closer look at the coyote. I’ve had several noteworthy encounters with coyotes in the West over the years, while hiking in Idaho, New Mexico and elsewhere. And my field notes for sightings of other carnivores cover a lot of pages. There was, for example, the carnivorous badger that greeted me with a snarl as I rounded a bend in the trail while hiking up to a better fishing hole along a Rocky Mountain trout stream in central Idaho.
Wildlife biologists have long known that coyotes in the Northeast are bigger than their Western cousins, but there has been debate over whether the cause is genetic or environmental. A recent study by Roland Kays, mammal curator at the New York State Museum, comes down squarely on the side of genetics: the Eastern coyote is part wolf.
While scientists have postulated a connection between coyote and Canus lupus (wolf), Kays told the Adirondack Explorer newspaper the study has proven that link. “One of the big results was to show this in a systematic way,” Kays told Explorer writer Phil Brown.
Kays and two colleagues tested the DNA from 686 coyotes and measured the skulls of nearly 200 specimens. They found not only that Adirondack coyotes are part wolf, but also that their skulls are wider and larger overall – that is, more wolf-like – than the skulls of typical coyotes. The Adirondack coyote’s bigger skull and body give it an advantage in hunting large prey, like deer.
“It’s got enough coyote in it to live around humans, but enough wolf to take down ungulates,” Kays told the Explorer.
Some life history: Coyotes evolved as hunters of rodents – small game – in the Great Plains, but migrated east in the last century, partially filling the predatory niche once occupied by timber wolves (which were extirpated from the East in the 1800s.) Some coyotes reached Pennsylvania and New York via Ohio, traveling south of the Great Lakes, while others went north of the lakes into Canada, where they bred with wolves, and then moved south into New York and New England, according to the study by Kays and others which was published in Biology Letters.
The two populations later met in western New York and Pennsylvania. Unlike the Adirondack coyotes, those that arrived in New York via Ohio remained the same size as their Western counterparts. Kays said that since both populations live in similar habitats – woods filled with deer and other prey – genetics, not environmental factors, must account for their physiological differences.
Kays also says that coyotes of the North Country in New York show far less genetic diversity than coyotes that migrated eastward through Ohio. This suggests that the population is descended from a few females that crossed the St. Lawrence River from Canada.
Despite its mixed genes, the hybrid remains more coyote than wolf, according to Kays. In a sense, though, the wolf has returned to the North Country, only in a different form. “It’s interesting to show that evolution is still happening,” Kays told the Explorer’s Brown. “It’s not something you observe just in fossils.”
You can read more about the “coywolf” and look at a picture of a mounted specimen by clicking on a Burlington, Vt., Free-Press article at http://www.burlingtonfreepress.com