Posts Tagged ‘coyote evolution’

Coyote (Canis latrans) Evolution

March 2, 2017

The coyote is a remarkably adaptable and intelligent animal. The evolutionary history of this species began about 43 million years ago when its ancestors, the caniforms (dogs, bears, weasels, skunks, and raccoons) diverged from the feliforms (cats, hyenas, mongoose, and civets).  The canis genus likely originated in North America over 5 million years ago, having evolved from a primitive wolf-like animal known as eucyon.  Johnston’s coyote (Canis lepophagus) was an early member of the canis genus that lived in North America during the Pliocene from ~5 million years BP-~2 million years BP.  Most paleontologists who study the anatomy of canids believe C. lepophagus was ancestral  to wolves, coyotes, and dogs. Wolves crossed the Bering land bridge and colonized Eurasia, while coyotes stayed in North America.

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Canis lepophagus attempting to scavenge a carcass of a llama defended by a Borophagus, the bone-eating dog.  This illustration depicts a scene that may have occurred during the early Pliocene or late Miocene over 3 million years ago.  Canis lepophagus is thought to be the common ancestor of wolf, dog, and coyote.

At the Rancho La Brea Tar Pits in California coyote bones are the 3rd most common specimens to be excavated here behind dire wolves (Canis dirus) and saber-toothed cats (Smilodon fatalis).  Timber wolf (Canis lupus) skeletal material is present but uncommon.  The abundance of carnivore specimens from this site allows scientists to study changes over time in the anatomy of these species.  Ice Age coyotes from this locality were larger and more powerful than present day coyotes, and they had larger jaws and teeth.  There are probably a couple of reasons for this size disparity.  Pleistocene coyotes hunted larger prey and had a better diet.  They may have hunted juvenile individuals of megafauna species such as horse, bison, camel, and llama; and there was more meat to scavenge.  Moreover, they had to compete with larger carnivores and likely lived in bigger packs.  Dire wolves competitively excluded timber wolves from coyote range.  This benefitted coyotes as well because there was less of an ecological niche overlap between dire wolves and coyotes than there is between timber wolves and coyotes.  Less than 1000 years after the extinction of the Pleistocene megafauna, coyotes evolved to their present day size and stature.

Dire wolves are long gone and timber wolves have been extirpated from most of their former range, but coyote populations are increasing, and they have re-colonized eastern North America within the past century.  Coyotes are 1 of the few carnivores smart enough to avoid poison bait and traps.  Studies show they produce larger litter sizes in response to human hunting pressure.  Though human hunting of coyotes may cause a temporary decrease in their populations, in the long term their populations increase because they begin producing larger litters.  This explains why their populations increase despite being considered a pest that can be hunted year round with no bag limit.

Coyotes in northeastern North America interbred with the last timber wolves in eastern Canada and dogs, and these coyote-wolf-dog hybrids live in large cities and suburbs.  Genetic studies suggest these hybrids are 65% coyote, 25% wolf, and 10% dog.  Characteristics inherited from dogs help them tolerate urban noise, and some have even learned to look both ways before they cross roads.   They’ve adapted well to living on golf courses, city parks, abandoned farmland, vacant lots, cemeteries, and roadside ditches where they have frequent access to roadkill.  I think coyote-wolf-dog hybrids have colonized southeastern North America as well.  I’ve seen some that look like western coyotes, and others that resemble wolves.  More genetic studies of southeastern coyotes may confirm my hypothesis.

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Coyote-wolf hybrids have colonized northeastern North America.  I hypothesize some coyotes in southeastern North America have also bred with wolves and dogs.

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These photos help distinguish between coyote-wolf hybrids and pure bred coyotes.  I’ve seen canids in Georgia that resemble both.

Reference:

Meachen, Julie; and Joshua Samuels

“Evolution in Coyote (Canis latrans) in Response to Megafaunal Extinctions”

PNAS 2012

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