Scientists have recognized for a while that Adirondack coyotes are bigger than western coyotes, but there has been debate over whether the cause is genetic or environmental.
Although scientists have suspected a wolf connection, Kays said the study proved it. “One of the big results was to show this in a systematic way,” he said.
Kays and two colleagues, Abigail Curtis and Jeremy Kirchman, tested the DNA from 686 coyotes and measured the skulls of 196 specimens. They found not only that Adirondack coyotes are part wolf, but also that their skulls are wider and larger–that is, more wolflike–than the skulls of typical coyotes. The Adirondack coyote’s larger skull and body give it an advantage in hunting deer.
“It’s got enough coyote in it to live around humans, but enough wolf to take down ungulates,” Kays said.
Coyotes evolved as hunters of rodents and other small prey in the Great Plains, but they migrated east in the last century, partially filling the niche once occupied by wolves (which were driven out in the 1800s). Some traveled south of the Great Lakes, reaching New York State via Ohio. But others went north of the lakes into Canada, where they bred with wolves, and then moved south to the Adirondacks and New England, according to the study, 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 dwell in similar habitats–woods filled with deer–genetics, not the environment, must account for their physiological differences.
Kays also noted that Adirondack coyotes exhibit far less genetic diversity than coyotes that migrated through Ohio. This suggests that the population is descended from a few females that crossed the St. Lawrence River from Canada.
Despite its lupine genes, the hybrid remains more coyote than wolf, according to Kays. In a sense, though, the wolf has returned to the Adirondacks, only in a different form.
“It’s interesting to show that evolution is still happening,” Kays said. “It’s not something you observe just in fossils.”
NOTE: This article appears in the November/December issue of the Adirondack Explorer.