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.
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.