Sunday, August 23, 2015

Wolf, Coyote, or Coywolf? New Science On Wolf Hybrids

eastern wolfUnlike Little Red Riding Hood, most of us can tell the difference between a wolf and Grandmother. But beyond that: our wolf identification skills are probably not as good as we think.

Consider the names bandied about the popular media today: gray wolf, red wolf, coyote, coywolf, coydog. Which of these are species? What is the real deal with hybrids? What does it mean for conservation?

The answers are not simple, in large part because the topic of wolves and wolf hybrids often resides more in the realm of folklore than biology. A good way to pick a fight in any bar in rural America is to start offering opinions on “Canadian gray wolves” or “coywolves” or “eastern coyotes.”

What does the science say?

A new paper in the journal Biology Letters uses the latest genomic techniques to give a clearer picture of canid taxonomy and hybrid origins. The researchers used a technique called restriction site association DNA marker sequencing (RADSeq) and genomic simulations to resolve the hybrid status of wild canines in North America.

It’s only in the last ten years that these techniques have been developed to be able to understand complicated biological systems — not just in humans and fruit flies, but in wolves and all kinds of other creatures.

A whole new set of questions can now be answered with these genomic techniques – including questions about wolf hybrids.

Even the paper’s authors acknowledge that canine taxonomy can be, well… complicated.

“The genetics has gotten very complicated,” says the paper’s lead author, Linda Rutledge, post-doctoral researcher and instructor at Trent University, Ontario. “It’s very difficult for people to read genomic papers and understand them.”

So what should wildlife conservationists know about this research? Here are some key points.

urban-coyoteEastern wolves are a separate species.

The paper notes two prevailing evolutionary models for animals in the Canis genus in North America. One model maintains that there are two species of wild canids: the gray wolf (Canis lupus) and coyote (Canis latrans). Their comingling has also resulted in various hybrids.

The second adds a third species to the mix: the Eastern wolf (Canis lycaon).

For years, many have considered the Eastern wolf to be one of the hybrids of gray wolves and coyotes. This has led to confusion among policy makers and the general public.

The genomic research in this paper found no evidence that the Eastern wolf is a hybrid.

It’s a separate species.

Disagreement may be the biggest threat.

As geneticists debate, policy makers and wildlife managers base their decisions on confusing information. Or, more often: they feel paralyzed to make decisions.

Eastern wolves, though, need action. Their core population is centralized in Algonquin Provincal Park in Ontario. For many years, the animals could be legally shot as soon as they left the park.

That’s changed: there is now a buffer zone around the park that prohibits all hunting and trapping of wild canids.

But beyond that, protection of eastern wolves in Ontario is largely on paper only. Why? The eastern wolf is difficult to tell apart from the coyote. And coyotes can be hunted or trapped year round, without bag limits.

So it’s essentially open season on eastern wolves in potential expansion areas.

The paper’s authors hope that establishing the evolutionary history of the eastern wolf, demonstrating it is a species and not a hybrid, will lead to better protection.

“The eastern wolf needs a recovery plan that extends into dispersal areas, including Quebec,” says Rutledge. “There is wonderful habitat for them to disperse into; there just needs to be protection so they are not killed as soon as they disperse out of the buffer zone.”

Eastern Coyotes, Great Lakes Wolves are hybrids.

The genomic testing revealed three species of canids, but there are also hybrids arising from these species encountering each other.

Here is what the paper argues about hybrids.

Eastern coyotes are hybrids of western coyotes and eastern wolves. This is the animal often referred to as the coywolf.

Following extermination of wild canids in the eastern United States following European colonization, western coyotes began colonizing the habitat – and bred with eastern wolves when they encountered them on their expansion.

Great Lakes wolves are hybrids of gray wolves and eastern wolves.

Red Wolves, Eastern Wolves likely same  species.

The researchers did not test for red wolves for this paper, but relied on a body of work conducted previously.

These animals, once found in the southeastern United States, became critically endangered in the 1900s, and the last wild animals were gathered and placed in captive breeding facilities.

The captive breeding of a small population may have caused their genetics to diverge from eastern wolves. They have been since been reintroduced in sites of the Southeast – where they breed readily with coyotes, perhaps further confusing the genetic situation.

“The attention and controversy around wolves is all cultural, not biological,” says coauthor Paul Hohenlohe, assistant professor of biology at the University of Idaho. “But the reality is the biological situation is also complicated. It’s not static.”

Arguments about wolf management and conservation can quickly descend into trying to reconstruct the past. What wolf really belongs in the East? Were gray wolves there? Are Canadian gray wolves the same as Rocky Mountain wolves?

Historical records don’t help. European explorers were not taxonomists, let alone geneticists. They called things by confusing and inconsistent names: brush wolf and gray wolf and black wolf could all mean the same thing, or be perceived as different species.

And so obsessing over what canine belongs where can seem a futile quest.

Lead author Rutledge proposes another way for conservationists to approach this: focus on the ecosystem not the species.

“Conservation focuses on a very species-specific model,” she says. “Agencies often want to know first whether a species is taxonomically valid, but that may not be an efficient way to approach conservation in general. Our research shows that what species are can be very difficult to pin down.”

“But we know that ecosystems need top predators,” she continues. “That is so clear in the case of over-abundant white-tailed deer in eastern forests. The eastern wolf could play that role, if it could disperse.”

In other words: Let’s quit trying to make wolves fit into our neat little taxonomic boxes. Let’s focus instead on how to protect and restore their critical role as top predators.

Photos: Above, an eastern wolf in Algonquin Park (Photo by Michael Runtz); and below, a Wisconsin coyote (Photoby Matt Miller).  All photos courtesy The Nature Conservancy.

A version of this story first appeared on the Nature Conservancy’s blog Cool Green Science.

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Matt Miller is a senior science writer for the Nature Conservancy. He writes features and blogs about the conservation research being conducted by the Conservancy’s 550 scientists.

Matt has served on the national board of directors of the Outdoor Writers Association of America, and has published widely on conservation, nature and outdoor sports.

11 Responses

  1. Bruce says:

    Wow, a lot of material to digest here. One thing which stood out in this article and the one on Canadian Grey Wolves was the idea many have that wolves routinely kill off coyotes within their ranges. Apparently, they seem to not only co-exist, but interbreed to a lesser or greater extent depending on wolf species, leading me to believe wolves and coyotes occupy somewhat different niches on the food chain, so competition is not as fierce as believed.

    It also seems possible, considering the fact coyotes have dispersed into every state, that they are more wanderers rather than home territory creatures like wolves. I remember reading in the media about coyotes and coydogs being hunted in NY in the 60’s, so they’ve been there for a long time. In fact, I seem to remember the state encouraging hunters to deliberately hunt these animals, especially in winter. I don’t recall if this involved a bounty of some sort.

    All this brings up a question: if wolves of whatever species should repopulate the Adirondacks, how many of us are really qualified to tell the difference between a protected wolf, and a coyote, coywolf, or coydog if experts need DNA to be sure in many cases? Another question might be if folks are seeing what they believe to be wolves, how much of their belief is based on wishful thinking and mistaken identity?

  2. Paul says:

    Matt, since it is so easy for these different “species” to inter-breed I wonder why scientists don’t use sub-species designations like we see with deer. Speciation is supposed to be at least a somewhat of an evolutionary barrier. For example many of us Homo sapiens look and act very differently and come in all different sizes but since it we can interbreed we are the same species. Why doesn’t the same rule for taxonomy apply here?

  3. Tim=Brunswick says:

    What an unbelievably ridiculous philosophical discussion/story. There is no over-population of deer/moose in the Adirondacks for sure and you people rant about bringing in wolves!

    Wolves DO kill coyotes and …yes they DO mate with them under certain circumstances, but when competition for food/territory is serious ( i.e. ..ADK’s), it is not likely to happen. Even if it does, you can call them what you want during your doctoral chats, they’ll still kill deer, moose, pets and anything else they find when the opportunity arises and they’re hungry!

    The ADK’s aren’t broken, but by golly let’s talk about fixing it……….

    • Bruce says:

      Tim, no one has suggested wolves do not kill coyotes, only that it may not be as prevalent as people think. I don’t believe you actually read the article, because if you had, you would have seen that it was not about bringing wolves into the Adirondacks at all, but a paper helping to dispel some erroneous notions about wolves and their wild kin.

      I’m at a loss to know what it is you have against information designed to help people be better informed, unless you’re afraid better informed people might make decisions you don’t agree with.

    • Boreal says:

      I disagree about the deer herd. When I was young, I had to hunt to find deer. Now, I spend half of my time and money repairing/replacing landscaping and picking off Lyme-infested deer ticks because of deer on my property. But I am not allowed to kill them, being within the village limits. There is certainly an over-abundance in my area.

  4. Marco says:

    Paul, I believe it does apply. I do not believe the offspring are fertile or, to put it another way, the offspring cannot have offspring. Otherwise they would be simply a sub species of a single species. While we don’t see it all that much today, a mule was the offspring of a horse and donkey. He is not a separate species, since, he cannot produce viable offspring. Indeed this is the very definition of a species.

  5. Dave Gibson says:

    Thank you very much, Matt Miller, for this important posting and overall message, easily absorbed by a general readership. Well done.

  6. Bruce says:

    A couple of recent articles I found on verified wolves in, or very close to the Adirondacks. Are they closer than we think?

    A small pack has been filmed by wildlife officials in the Mt. Shasta area of California, the first documented wild wolves in CA in over 100 years. They are believed to have come from Oregon, some 80 miles away, down the Sierras.

  7. Mike says:

    Whatever they are genetically, these animals have decimated the deer population in the central Adks. I’ve heard them, early morning and at dusk, they sound like wolves not coyotes. Coyotes and wolves I’ve heard elsewhere, and these sound like wolves. I’ve seen their large tracks, scat and at times fleeting glimpses of them, and worse I’ve seen their carnage and destruction, fawns, yearlings, does, even mature bucks. Year ’round they pull them down, but what they do in the winter deer yards is nothing short of a massacre, and would make the strongest of us weep at their wanton and wasteful killing. They need not be encouraged.

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