Saturday, September 13, 2014

Meet the Coywolf: Nature's Next Top Dog?

By Brian Stallard
Sep 02, 2014
Western Coywolf
(Photo : Mech et. al./doi:10.1371/journal.pone.0088861.g002) 
Even while pure grey wolf populations continue to recover in North America, the top dog has been, and may continue to be, the coywolf. A hybrid of coyote, wolf, and even wild dog, this species appears to be one of the most successful predators in the United States, despite the fact it is one of the least protected animals.

Wild grey wolves were all but wiped out by overhunting in the United States in the early 1920s, allowing coyote populations to explode in once-suppressed regions and spill over into new territory. Now coyotes can be found in nearly every territory wolves once roamed.

Coyotes are not the only top predators in these regions. There's a larger and more dangerous top-dog too. The coywolf, or Eastern coyote, is a larger coyote with wolf-like features that can be found in land north of the Great Lakes.

Past field studies have found that despite their dominant coyote features, coywolves behave like the apex predators that once inhabited the region - hunting in packs and having a complex social structure. The Western coyote, on the other hand, is primarily a loner except during mating and birthing seasons.

A Heck of a Mutt

Just last month, the renowned science journalist Moises Velasquez-Manoff wrote in New York Times Magazine that it is largely thought that the coywolf is roughly one-quarter wolf and two-thirds coyote, with the rest being dog -  a "canis soup" of mixed genes that Bradley White, a scientist at Trent University in Peterborough, Ontario, believes is the direct result of desperate and packless grey wolves breeding into coyote populations in the wake of their decline.

"The result has been a creature with enough strength to hunt the abundant woodland deer," Velasquez-Manoff wrote, "as much as 40 percent larger than the Western coyote, with powerful wolflike jaws."

The North American Grey Wolf (left) compared to the Western coyote (right)
(Photo : Flickr: Eric Kilby/Justin Johnsen (modified)) The North American Grey Wolf (left) compared to the Western coyote (right)
However, what's interesting is that this has never truly been proven. In fact, coyotes and grey wolves famously don't get along, bullying one another out of regions despite the fact that they only share some, and not all, resources.

A study published in the Canadian Journal of Zoology back in 2000 revealed that there is a chance that grey wolves and timber wolves from different parts of North America are two separate species entirely. That then lead experts to the theory that the timber wolf is a wolf species that specifically evolved from a coyote-like ancestor, while grey wolves emigrated to North America over the Bering Strait. Such a theory could explain why timber wolves (sometimes called "eastern wolves") can hybridize into the Eastern coyote despite what appears to be a base hatred between grey wolves and North America's smaller canine.

Still, a paper published in Heredity, a Nature publication, back in 2010 revealed that Eastern wolf and coyote populations often boast genetic information specific to timber wolf fathers and coyote mothers. This raised a new set of questions: was the timber wolf actually once a hybridization between coyotes and grey wolves? Does that then mean the coywolf is a hybridized hybrid?

Manmade Coywolves?

Before things got any more complicated, a team of wildlife researchers set out to determine once-and-for-all if pure male grey wolves (Canis lupus) and female Western coyotes (Canis latrans) can indeed make what looks and even functions like a coywolf on their own.

The results were published in the journal PLOS One earlier this year, and were not exactly as clear as the experts would have liked. Out of nine artificial inseminations over two breeding seasons, only three coyote mothers became pregnant.

"One coyote ate her pups, another produced a resorbed fetus and a dead fetus by C-section, and the third produced seven hybrids, six of which survived," the authors reported.

three lab-born 50/50 coywolves
(Photo : Mech et. al./doi:10.1371/journal.pone.0088861.g002) Three lab-born 50/50 coywolves.
What's interesting, however, is that while one out of three is pretty bad odds, the six survivors proved to be successful hunters - displaying a pack mentality even while boasting the adaptable scavenger guile of coyotes.

The authors add, "while our study adds information to the controversy, it does not settle it. Further study is needed to determine whether the putative Canis lycaon ["coywolf"] is indeed a unique species."

Did You Say "Chupacabra?"

Besides being a potentially unique species, the coywolf could also be the unexpected inspiration of a legendary monster.

The Chupacabra, a mysterious beast that reportedly ravages livestock in the deep south and across Mexico, may be nothing more than a bunch of mangy hybrids.

That's according to relatively recent DNA analysis of the "Texas Blue Dog," a creature that had reportedly killed 28 chickens on a Cuero ranch owned by  Phylis Canion.

According to the Science Channel's The Unexplained Files, Canion, a nutritionalist and wildlife enthusiast, discovered her chicken were all being slaughtered in the same brutal fashion over the course of a month - with throats torn and bodies drained of a great deal of blood.

"It opens the throat in the jugular," Canion had told the Huffington Post. "It seems to like the taste of blood, which is interesting because the only animal that is set up to suck blood is the bat."

A coyote or Mexican coywolf with mange. It is thought that most
(Photo : Flcirk: Calgary Reviews) A coyote or Mexican coywolf with mange. It is thought that most "Chupacabra" sightings are actually these unfortunate animals.
Because the kills were left where they fell, rather than being dragged away like most scavengers would, Canion believed that the predator responsible could be linked to legends of the chupacabra, which is notorious for draining the blood of its victims.

Canion and her neighbors later found the bodies of three hairless and dog-like beasts and had samples sent away for testing.

In 2007, initial DNA analysis from Texas State University came back positive for a Mexican coyote with severe mange - an illness that causes hair loss. Further analysis investigating strange skeletal proportions and a blue tinge to the beast's skin revealed that the creature may have been a Mexican wolf and coyote hybrid - an uncommon cousin to the northern coywolf.

However, even if a coywolf is one chupacabra, it might not be all. Dozens of sighting of the mysterious creature have been made over the years, and many still speculate that it is its own elusive species.


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