Wolves of the Northeast deep woods have interbred with western coyotes, and the hybrid coywolves now thrive among us
I have never seen a wolf or coyote, outside of a zoo. An urban college professor, I have lived for the last 45 years in suburban Saint Louis. A red fox family once graced our subdivision for a few years, but never a coyote “yip” or wolf “howl” have I heard in our well-groomed neighborhood, no wild fur have I seen.
Until last month. Driving along a city street passing through a patch of woods not one hundred yards from a traffic light intersection, I saw something my eyes had a hard time believing. Dashing from the trees to my right and across the street in front of my car was a coyote, a really big one! Its tail streaming behind, it soon vanished into the patch of forest to my left, a brief apparition that engraved itself on my memory.
At least I thought it was a coyote. Big, though, for a coyote, heavy set rather than slender. Too small to be a wolf like those I had seen at the zoo, so probably not a wolf. Not a dog, either – of that I was certain. While it was the size and build of a really big German Shepard dog, there was no escaping the appearance — the long red-grey fur of its coat and its full furry tail – of a coyote.
What I had seen, it now appears, was a coywolf.
Grey wolf – coyote hybrids don’t happen
Four species of the genus Canis live in North America: coyotes and three kinds of wolves (grey, eastern, and red). Grey wolves like the one in the photo are the most ancient of the four species, diverging from the other three 1-2 million years ago. Coyotes diverged from eastern and red wolves much more recently (150,000 – 300,000 years ago); as a consequence, coyotes are quite a bit closer genetically to these two wolf species than they are to the grey wolf.
Because of the great genetic distance between them, hybrids between coyotes and grey wolves are extremely rare. Several hybrids have been produced in captivity using artificial insemination, but in the wild hybrids simply don’t happen.
So what is it that I saw? Too small for a coyote (as in the photo), and, besides, coyotes have never been common so far east as Missouri. However, it seems things have been changing. The trigger has been civilization. Over 400 years of clearing forests for farming in eastern North America and the hunting of wolves that has accompanied this clearing has led to a drastic population decline in eastern wolves. Like a falling chain of dominos, this decline has led to a chain of consequences, each triggering the next. The steep reduction in numbers of eastern wolves opened the door to an invasion of coyotes, moving into the wolves’ fast-emptying ecological niche from the coyote’s prairie homeland to the west. The dearth of available wolf mates facilitated the mating of the remaining eastern wolves with their new coyote neighbors.
Biologists think the initial hybrids were produced among dwindling wolf populations in southern Ontario, Canada, perhaps a century ago. As decades went by, the dogs that accompanied the farmers were added, like seasoning, to the genetic mix. Because of their genetic similarity, the wolf-coyote-dog hybrids were vigorous and successful – more successful, it turns out, than either parent species in the rapidly-changing environments of the ever-more-densely-populated northeast.
The coyote-eastern wolf hybrid has been formally labeled the “eastern coyote,” but the name has not stuck, as the new beast is a long way from a coyote. The hybrid animals now numbers in the millions and are found throughout eastern Canada, in every eastern state north of Virginia, and as far west as Missouri. A study last year of the genetic makeup of 437 of these hybrids living in ten north-eastern states and Ontario revealed DNA which on average is 64% coyote, 26% wolf, and 10% feral dog. The resulting critter is informally but widely known as a coywolf.
Is the Coywolf a species?
So what are we to make of the coywolf? Should we think of it as true species, a fifth American member of the genus Canid? Many argue “no,” that the coywolf is just a transient, an accident of circumstance that will not persist. Continued mating with feral dogs will inexorably dilute the mix, these naysayers claim. If its genetic makeup is not constant, how can it be thought of as a species, they question. Other biologists disagree with them, pointing out that the anatomy and genetic makeup of coywolves is quite different from that of wolf, dog or coyote, and that there is little evidence of continued admixture of coywolves with dogs. All over the northeast, the coywolves look the same, and coywolves are now common in places where wolves and coyotes are not found (like Saint Louis). Isn’t that enough to qualify as a species?
Any high school student taking biology will be familiar with the biological species concept, which defines species as groups that are genetically sequestered – that is, that do not interbreed with other species. By this definition, coywolves are not a true species, as they freely interbreed with dogs (and presumably with wolves and coyotes). But by this same definition, wolves and coyotes are not true species either – after all, it was their interbreeding that produced the coywolves in the first place!
So there is lots of room to disagree. On balance, I don’t see a problem with accepting coywolves as a provisional species, a functional biological unit. Linnaeus knew little about the breeding behavior of the species he named. He looked for characteristic differences shared by all members – a way to identify an individual as a member of a group. I am happy to live by that limited definition. What I saw was — a coywolf.
Living amongst us
The coywolf I saw bounding across the road didn’t seem to be having any problem living in the middle of the Saint Louis suburbs. He knew how to cross the street in traffic, how to keep out of sight during the day, and big as he was, he certainly wasn’t having any trouble finding things to eat.
What does an urban coywolf eat? Fast of foot and with big jaws, catching squirrels presents no problem (the squirrels in my yard as dumb enough even the dogs catch them). Pets also prove tempting targets. Studies of coywolf droppings reveal many cats are eaten. Adult Coywolves weigh in at about 55 pounds (25kg), twice the size of a coyote and strong enough to take down a small deer. With the population explosion of urban deer, coywolves may provide an ecological counterweight, keeping the numbers of deer down. Unlike wolves, coywolves like hunting in open terrain. They now live in a vast area east of the prairies where coyotes have never lived and where wolves have long since been exterminated. Now common in rural areas, they also populate the suburbs, and are even urban, living in big cities like Boston and Washington — New York City is said to harbor a population of some 20!
Those who study coywolves say their cries are a mixture of their ancestors’ cries. They start off with the deep-pitched howl of a wolf, sliding into the higher-pitched yipping of a coyote. I have not heard this cry in Saint Louis. But now, of an evening, I find myself listening.