Why do coyote females have larger litters in heavily hunted areas?

I have a lot of quibbles with Dan Flores’s book, Coyote America. Among them is a contention that coyotes howl because it allows them to “take a census.”  If no other coyotes howl back, the females wind up releasing more ova and having larger litters. This description, which Flores calls an “autogenic trait,” cannot be found anywhere in the coyote literature. His account is not described in the book, but it is mentioned in his interview with National Geographic and on The Joe Rogan Experience.

I have no idea where Flores got this idea, but it’s not really what happens. The literature on why coyotes have larger litters in areas where they have been heavily hunted says that the larger litter sizes are associated with better access to food resources. The best-known paper on this issue comes from Eric Gese, a researcher with the USDA, who studied coyote population dynamics in an area of Colorado.

Gese contends that what happens with coyotes in pressured areas is that the surviving females are healthier, simply because they have access to more food resources. This greater health causes them to release more ova during the estrus cycle, and this increase in ova results in greater litter sizes.

It is not because the coyotes are taking census and can somehow magically figure out that they should produce more young.  It is simply that the coyote females’ own bodies respond to greater food resources by becoming more fertile.

What has possibly evolved in coyotes is that they have a tendency to become significantly more fertile when the females are at their most healthy. This is a great trait for a mesopredator to have.

After all, coyotes evolved in North America with dire wolves and a host of large cats breathing down their necks. Natural selection favored those that could reproduce quickly if populations were dropped dramatically.

But it’s not because of some “autogenic trait.” It is simply how coyote populations expand as mesopredators with increased or decreased access to prey.

So yeah, my take on Coyote America is that it is mostly a science fiction book. Not only does he mess up the exact genetic difference between a wolf and a coyote, which is not equivalent to the genetic difference between a human and an orangutan (as he claims),  he also messes up that coyotes really do hunt down and kill cats and eat them. They are not just killing a competitor. They are using cats as a food resource.

This was a book I was so looking forward to reading. It got good press, but the actual science in it was so lacking.

 

Read Full Post »

Forrest Galante discovers a possible coywolf in the Sierras

Forrest Galante hanging out with a socialized wolf that has features similar to the Southern Rocky Mountains gray wolf.

As long-time readers of this blog know, I am a huge fan of Forrest Galante’s Extinct or Alive on Animal Planet.  In the new season, he documents the discovery of the Fernandina tortoise, a Galapagos giant tortoise that has been declared extinct in the wild.  He also has found an unusual giant lion in Zimbabwe that has genetics that cannot be described to any known form of lion in Zimbabwe and might be descended from the massive Cape lion of South Africa.

So yeah, I love this show. The most recent episode involved looking for the Southern Rockies gray wolf in the Sierras of California. Some canid had been killing cattle in that part of the world, and when Galante’s team went into the region looking for the animal, they found lots of interesting things. With use of a German shepherd tracking dog, he discovers a massive deer that has been killed by a canid, and later investigations revealed a large canid that left massive tracks in the snow.

He finally captured the animal on trail camera, and he initially thought it was a wolf. But it had too many coyote-like features to suggest that it was pure.  So Galante surmised that this animal was a coywolf.

Now, this raises a lot of questions. One is that no one has ever seen a coyote-wolf cross in the West before. We know that they exist or existed because the genomes of Western wolves suggest some tiny amounts of coyote ancestry. But no one has seen one before in the West.

Further, the first wolf to enter California from Oregon was noted for his friendly relationship with coyotes. This wolf was of the Northwestern wolf subspecies, but it is possible that he passed some genes into the coyote population.  In recent years, wolves have colonized and bred in California. One pack, called the Shasta Pack, mysteriously disappeared, either killed by poachers or just dispersed. It is possible that a survivor of this pack wandered south into the Sierras and bred with a coyote.

So Galante is finding lots of interesting things in the wild.  One thing I did sort of quibble with in the episode is idea that wolves and humans were at constant enmity in indigenous cultures. Yes, there was conflict between hunting man wolves on this continent, but the work of Raymond Pierotti and Brandy Fogg has revealed that many indigenous cultures had a close relationship with wolves, which often bordered on something like a pre-domestication symbiosis. He played up potential conflicts between indigenous people and wolves, but reality was a lot more nuanced than that.

Also, I don’t think most people are aware of the really upsetting discovery that gray wolves and coyotes last shared a common ancestor only around 50,000 years ago and that the two forms of canid have exchanged genes across the continent. That discovery has been sort of paradigm shattering for me. I have never looked at coyotes the same way since it came out.

Wolves and lions were once the most widespread large predators in the world. Depending upon which version of lion taxonomy one prefers, the American lion was either a subspecies of modern lion or a lineage of cave lions, which were a sister species to the modern lion.  If one considers it the former, then lions had a much larger range than gray wolves ever did, but if one considers it the latter, then gray wolves were the most widely distributed large predator.

It should be no surprise that lions and wolves have lots of mysteries lurking in their double helices.  Galante is getting the public to look at these animals with new eyes.  Lots of hidden things are there to be discovered.

More work need to be done to document Galante’s coywolf, but it is something that should be taken seriously.

 

Read Full Post »

Possible reinforcement in wolf and coyote “speciation”

An F1 cross between a gray wolf and a coyote that was produced through artificial insemination.

A few months ago, I wrote about a discovery that two species of howler monkey have evolved greater genetic divergence in a hybridization zone in southern Mexico. The hybrids were less fit to survive or reproduce, so natural selection has favored those individuals in both species that were genetically more divergent where their ranges overlap. This phenomenon, known as “reinforcement,” is a powerful tool that maintains both species as distinct.

I have been thinking about how this phenomenon may have played out in wolf evolution in North America.  We have found that gray wolves across North America have at least some amount of coyote introgression, which has been revealed in several full genome comparisons.

The wolves that have most evidence of coyote introgression are those that live in areas that were not in the historic range of coyotes, while those with the least coyote introgression tend to be in the areas where gray wolves and coyotes were sympatric.

It is possible that something like reinforcement went on with wolves and coyotes living in the West. Hybrids between gray wolves and coyotes were probably less likely to be able to bring down large prey or were too large to live on small game, which is the staple diet of most Western coyotes. Over time, reinforcement through natural selection could have caused greater genetic differences between Western wolves and coyotes, and Eastern wolves were without coyote and thus never developed these greater genetic differences.

When coyotes came into the East, they mated with relict wolves, so that we now have whole populations of wolf with significant coyote ancestry.

Now, this idea is not one that I find entirely convincing. One is that ancient mitochrondrial DNA analysis from wolves in the East suggests they had coyote-like MtDNA, which, of course, leads to the idea that the wolves of the East were a distinct species.

Further, the discovery of the recent origins of the coyote makes all of this much more murky.  Again, reinforcement is a process that is only just now being sussed out in the literature, and gray wolves and coyotes are unique in how much introgression exists between them.  Their hybridization has essentially been documented across a continent. The only wolves that have no evidence of coyote ancestry live on the Queen Elizabeth Islands of the Canadian arctic. No coyotes have ever lived on these islands, so they have never introgressed into the wolf population.

The howler monkeys in the reinforcement study hybridize only along a narrow zone in the Mexican state of Tabasco. They are also much more genetically distinct than wolves and coyotes are. The monkeys diverged 3 million years ago, but the current estimate of when gray wolves and coyotes shared a common ancestor is around 50,000 years ago.

So gray wolf and coyote “speciation” is a lot more complex than the issues surrounding these monkeys.

But reinforcement is something to think about, even if it doesn’t fit the paradigm exactly.

 

 

 

 

 

 

Read Full Post »

Panamanian coyotes are interbreeding with dogs and eyeing South America

The coyote has spread to almost the entirety of the North American continent. They are absent from much of the treeless tundra of the Canadian High Arctic, but they are at home in Alaska and Labrador. They range all through the United States and through all of Mexico. They live in every Central American nation and are working their way through Panama.

A recent survey of coyotes and crab-eating foxes in Panama revealed that two species now have an overlapping range. The crab-eating fox (Cerdocyon thous) is widespread in northern South America, but only recently did a few of them wander into Panama.  This survey used a combination of camera trap and road-kill data to get an idea of where both canids live in the country.

Deforestation in Panama has opened up new territory for both species, which do much better in human-dominated environments.  Coyotes now are at the edge of the great forests of Darien. Beyond those forests lies Colombia– and a whole new continent.

Further, coyotes could possibly enter Colombia through a coastal approach, simply crossing onto the beaches of eastern Panama and walking down the coast.

Also, the researchers are noticing that some coyotes have dog-like features, which suggests they are interbreeding with village dogs. The dogs could confer onto the coyotes some advantageous genes that might make colonization of South America easier.

So my guess is it won’t be long before coyotes make it to Colombia, and when they do, they will be the first wild Canis species to enter that continent since the dire wolf.

No, they aren’t as impressive in their forms as that creature was. But they are impressive in how they have thrived despite all humans have thrown at them.

Of course, when Panama was a province of Colombia, Panama was considered part of South America, and if that were still the case, we could already say they colonized the continent.  Many old maps of South America show Panama sticking off upper left of Colombia.

But whatever one thinks, coyotes are very likely to make it into Colombia. They will likely spread from there throughout northern South America. What this means for the native species of South America, we can only conjecture.

But it is going to be an interesting mess.

Read Full Post »

Something to admire about a coyote

Whenever this civilization met coyotes, be at Jamestown, the Indiana frontier, or along the Missouri River, our relations with them were not cordial. We came out of Europe. Europe had waged war on wolves, where wolf attacks on people and livestock were certainly a problem, but in the lands that became the United States, predators were cleared off.  The bigger forms of wolf held on in northern Minnesota and in the Texas and Louisiana pine woods.

The lead flew at the wolfy kind. So did the steel trap and poison. The coursing dog did its work, as did the tracking hound and the big grappling hunting bulldog or mastiff.

And the coyote, instead of becoming reduced to a mere relict range, wound up colonizing a whole continent. Coyotes are in Newfoundland and Alaska. They have expanded to the south as well, and now coyotes rest at the edge of the swamps of Darien in Panama. Beyond those swamps lies Colombia and a whole new continent to wander through.

This little wolf, which once picked at the dire wolf and Smilodon’s kills, thrives because of our persecution. We have killed countless numbers of coyotes over the years, and they now live nicely in virtually every city in the country. Everyone lives near coyotes now. They don’t have to worry about larger predators driving them or killing them. They can live nicely on garbage and cats and the fruit from our ornamental trees.

There is something to admire about an animal that thrives in part because we’ve changed the ecosystems so much. The coyote is the biggest and most charismatic (and the most problematic) of these species, but the raccoon, the red fox, the skunk, the barred owl, and the opossum have all had their fortunes rise as we have “settled” this continent.

They are these barbarous dogs, unchained, uncollared, and untrained, that come slipping in.  We hate their liberty in the same way we hate a free-roaming dog, but we hate them more because they are the wolf we just couldn’t kill off.

We tried. Their biology just laughed at our vain attempts. And they are here, there, and everywhere to stay as the Anthropocene trundles on.

They got their start running the jackrabbits, which is one reason they can run with the swiftness and agility of a sighthound, and now, in their current hybrid “Eastern” form, they moved from lifting fawns from the coverts and have grown bigger and more wolfy to run down the adults.

This is a thriving beast, a utilitarian model that can live as a mousing fox, a scavenging jackal, or pack up and hunt like a proper wolf.

And you have to admire that versatility, that cunning, even if you hate them with every fiber of your being.

They got us buffaloed. And we didn’t see it coming.  It got our goat, because it watched where we tied it up.

 

 

 

Read Full Post »

Omnivorous and opportunistic coyotes are feeding on fruit, small dogs, and cats in Southern California

An analysis of coyote feces from various parts of Southern California has revealed something rather shocking.  Yes, coyotes are coming into people’s lawns and cultivated gardens and eating lots of fruit, but the analysis revealed that cats comprise 20 percent of their diet in urban areas.

This is in direct contradiction of Dan Flores’s contention that coyotes usually just kill cats because they are competitors and leave their carcasses to rot in the sun.  He makes this claim in both Coyote America and made it again on Joe Rogan’s podcast.   If cats comprise 20 percent of their diet, coyotes clearly are targeting them as a prey species.

If one thinks about it carefully, cats are about the best meat a coyote can get in most urban environments.  Where there is civilization, there are many cats. and when you’re  a 25-30 pound coyote, an 8-10 pound cat would sustain you for some time. Most indoor-outdoor cats somewhat fat and usually lack any skills for living in anything like “the wild,” so of course, coyotes are going to target cats.

One of the authors of the new study is Justin Brown, who also appeared on Joe Rogan’s podcast after Dan Flores. I much preferred the discussion with Justin Brown, who was polite and knowledgeable about urban carnivorans, but it was obvious that he disagreed with some Flores’s airy-fairy ideas about coyotes.

Indeed, I think the reason why Flores’s book about coyotes gets so much attention is that it does present the coyote in a way that sanitizes it from what it really is. Coyotes are predators. They do kill sheep. They do kill dogs. They do take cats. They have killed people, including fully adult Taylor Mitchell in Nova Scotia.

These facts should not make us want to exterminate coyotes. Indeed, when someone says they want to do such a thing, I wonder if they might have come up with a more realistic goal in life like blowing up the sun or draining the ocean.

We err when we turn coyotes into terrible predators that deserve only death, but we also err when we turn them into the prick-eared Labradors of nature.

We should admire the coyote as the one of those Anthropocene wolves, a sort of North American super wolf that has thrived in spite of our attempts to eradicate it from the landscape. We have to adjust our behavior to live with them. Not letting cats go outside is probably a good idea, not just for their own welfare but for the welfare of lots of native species that cats target in their hunting forays.

We also need to understand that livestock producers must deal with coyote depredations.  Yes, we can encourage them to use nonlethal methods.  However, we shouldn’t be as judgmental of someone killing the odd one to protect livestock.

So yes, we now have evidence that coyotes are targeting cats in urban environments. If we love our cats, we’ll keep them inside. Cats don’t need to be outside to be happy, and they will never become a coyote’s breakfast if they stay where the Old Song Dog won’t be able to catch them.

This shouldn’t have been much of a shock. A similar study in 2009 in Tucson, revealed that 42 percent of an urban coyote’s diet consisted of cat meat.

The discrepancy in these two studies probably comes from the fact that coyote predation upon cats has become much better known by the public in the past decade, and Californians probably have at least heard of the studies that show how many birds, small mammals, reptiles, and amphibians cats kill every year.

So yes, if you let your cat outside, you are taking risks. Some people think it’s worth it.  That’s okay, but don’t blame the coyotes for doing what comes naturally. They are trying to survive in an human dominated world, and you’re providing them with an easy, nutritious prey source.

Read Full Post »

Of coyotes, wolves, dogs, and men

Humans and the various canids belonging to gray wolf species complex possess the most complex relationship of any two beings currently living on this earth.  At one point, they are our cherished companions, often closer to us than we ever could be with other people, and on another point, they are the reviled predators that might take a child in the night.

We have clearly defined relationships with other predators. Leopards and cougars, well, we might hunt them for sport or photograph them in the wild. But we never become closely aligned with them, except for those eccentrics who dare to keep such dangerous predators as pets.

People living in the Eurasian Pleistocene brought some wolves into their societies.  Wolves and humans should have been competitors. We should have had the same relationship with each other as spotted hyenas and lions do in Africa now.  But at some point, humans allowed wolves in.

Raymond Pierotti and Brandy Fogg demonstrate that many humans throughout the world have had some kind of relationship with wolves. In some cases, it is or was a hunting symbiosis. In others, they were totemic animals.

In their work, Pierotti and Fogg contend that the relationship between humans and wolves broke down with the rise of Christianity in the West. I don’t think that’s when it broke down. It started to become complex when humans began to herd sheep and goats.

In Kazakhstan, wolves are hunted and revered at the same time. The Kazakh people herd  livestock, so they must always worry about wolf predation. Stephen Bodio documents this complex understanding of wolves in his The Hounds of Heaven.

“They hunt them, kill them, chase them with hounds and even eagles, take puppies and rear them live, identify with them, make war on them, and claim descent from them,” writes Bodio. This description sort of fits modern humanity’s entire relationship with this gray wolf complex. We pretty much have done and continue do almost all of these things.

Wolves, coyotes, and dingoes have killed people. So have domestic dogs. In the French countryside, wolf hunts were considered a necessity to protect human life, largely because has the longest and best documented history of wolves hunting people. The dispossession of rural peasants and the depletion of game in the forests created conditions where wolves would consider humans easy prey.  Lots of European countries have similar stories. And when Europeans came to North America, they knew about the dangerous nature of wolves, even if they had never even seen one themselves.

Humans have declared war on wolves in Eurasia and in North America. The wolf is extirpated from much of its former range in Europe. They live only over a limited range in the lower 48 of the United States.

Man fought the coyote with the same venom and lead he threw at the wolf. The coyote’s flexible biology and social behavior meant that all that effort would come for naught.  The coyotes got slaughtered, but they rebounded. And then some. And the excess coyote pups found new habitat opened up with big ol’ wolves gone, and they have conquered a continent, while we continue our flinging of lead and setting of traps.

In Victorian times, Western man elevated the domestic dog to levels not seen for a domestic animals. They became sentient servants, beloved friends, animals that deserve humanity’s best treatment.

And in the modern era, where fewer and fewer Westerners are having children, the dog has come to replace the child in the household. Billions of dollars are spent on dog accessories and food in the West.  Large sectors of our agriculture are ultimately being used to feed our sacred creatures.

A vast cultural divide has come to the fore as humans realize that wolves and coyotes are the dog’s wild kin. Wolves have become avatars for wilderness and conservation, and coyotes have become the wolves you might see out your front window.

Millions of Americans want to see the wolf and the coyote protected in some way. Dogs of nature, that’s the way they see them.

The rancher and the big game hunter see both as robbers taking away a bit of their livelihood. Humans are lions. The canids are the spotted hyenas. And their only natural state is at enmity.

Mankind’s relationship to these beings is so strangely complex. It greatly mirrors our relationship towards each other. We can be loving and generous with members of our own species. We can also be racist and bigoted and hateful. We can make death camps as easily as we can make functioning welfare states.

And these animals relationships with each other are just as complex. Wolves usually kill dogs and coyotes they find roaming their territories. But sometimes, they don’t. Sometimes, they become friends, even mates.  Hounds can be trained to run down a coyote, but sometimes, the coyote and the dog become lovers in the forest.

Social, opportunistic predators that exist at this level of success are going to be a series of contradictions. Dogs, wolves, and coyotes certainly are. And so are we.

It is what we both do. And always will.

Read Full Post »

The Wolves of the Anthropocene

For most of my life, scientists believed that the present era was still the Holocene.  Glaciers retreated with a global warming trend around 11, 650. Man went from being the apex predator over much of the world and became the apex consumer. Agriculture allowed our populations to expand, and we started to give up our wandering ways and became “civilized.”

It was generally believed that the past few centuries are but a continuation of this age, but now a growing number of scientists believe we have left the Holocene and entered into the Anthropocene. Several scholars have issues with this new distinction, but I think it is quite useful. In this era, human activity is the main factor affecting climate and ecology, which is why the age is named for the Greek word for human (anthropos).

The best argument I’ve seen for when this era began is 1610.  In this scenario, the era is dated to when European disease and conquest killed off enough Native Americans and enslaved and enough African had been enslaved to allow forests to grow back in former agrarian fields.  This process started in 1492, but by 1610, enough of those trees had grown to remove enough carbon dioxide from the atmosphere to push the planet into the Little Ice Age.

Darcy Morey and Rujana Jeger have a great model for understanding dog domestication as a change in trophic strategies.  In the Pleistocene ecosystems, most wolves were mesopredators, playing second fiddle to an ecosystem full of cave lions, machairodonts, large bears, and cave hyenas. When these wolves hooked up with people, though, they hitched their wagon to the species that often behaved as the apex predators in the ecosystems.  When humans switched to agrarian lifestyles during the Holocene, humans became apex consumers, and dogs joined us as beneficiaries of being allied to that apex consumer species.  During the Holocene, many wolves became apex predators, as the cave lions and other large predators became extinct.

I’ve always liked the framework that Morey and Jeger derived in this paper, but now that we’re entering into a new geological age, maybe we need to look at the change in trophic strategies of wolves in this new age.

Morey and Jeger don’t have a good framework for what happened to wolves in the Anthropocene, but across Eurasia and North America, wolves were gone from many human-dominated landscapes by the first decades of the twentieth century.  They existed only in isolated areas in Western Europe, and in the  lower 48 states of the US, they lived only in Minnesota and in an isolated region in East Texas and Louisiana, where the taxonomically controversially red wolves were located.

Large pack-hunting wolves were really in quite a bit of trouble.  In the United States, the coyote population began to expand out of its Western core range into the Great Lakes States. They eventually made to New England and the Maritimes of Canada, and they hybridized with relict wolves and the expanding population of domestic dogs.  Coyotes eventually colonized all the Eastern states, and as they did so, they largely became the apex predators in many parts of their range.

But in the 1960s, attitudes about wolves began to change. Many nations protected wolves, and there were often introduction plans in the works.  By the early decades of the twenty-first century, wolves were making significant comebacks in Germany and Italy. The wolves in Italy were often living very much like stray domestic dogs, living large at garbage dumps. Wolves live near large cities in Germany, and how these wolves are going to adapt to living in such human dominated environments is going to be a major question for researchers.

And in throughout Eurasia, we began to see that domestic dogs were mating with wolves.  Indeed, it is now estimated that a majority of wolves in Eurasia have relatively recent dog ancestry. 

Similarly, as coyotes expanded in North America, their genes began to work their way into the wolf population.  Yes, coyotes in a large part of the US have wolf ancestry, but we also have discovered that wolves across North America have coyote ancestry. Indeed, one interesting thing about these genome comparisons is that coyotes and wolves are much more closely related than we initially gleaned form mitochondrial DNA analysis. The calculation is that the gray wolf and the coyote last shared a common ancestor around 50,000 years ago.  This recent common ancestry has a taxonomic implication, which is that coyotes are themselves a divergent form of gray wolf in much the same way domestic dogs are.

In the Anthropocene, the wolves that have done the best have been the domestic dog and the coyote. The domestic dog’s ability to ingratiate itself into human society or live very nicely as an opportunistic scavenger/hunter on the periphery of humanity is a great gift.  The coyote can live as an opportunistic scavenger/hunter as well, and it also can live very nicely as a mousing fox or pack up and hunt deer.

Gene flow among wolves, coyotes, and dogs has made these entities much more fuzzy than we once thought they were. Dog genes are working their way into both the coyote and wolf population.  Strange pelt colors are popping up in the wild animals. The black coloration in domestic dogs was conferred onto the North American wolf population during the Holocene, but this same mutation for melanism has entered the coyote and Italian wolf population in very recent years. Dogs have introduced dewclaws on the hindlegs to some wolf populations, and I have seen photos of Eastern coyotes that have those hind dewclaws as well, which likely were introduced through breeding with domestic dogs.

Coyotes in the East are evolving larger size to become better predators of deer, but becoming larger and more effective ungulate hunters will have a trade-off. As carnivorous mammals grow larger, they become more and more dependent upon large prey to survive.  Very large wolf-like coyotes will lose their ability to live well on small prey and garbage.

So in the Anthropocene, dogs remain allied to the apex consumers. Some coyotes operate as apex predators, and some wolves live as opportunistic scavengers.

And as these creatures adjust their trophic strategies in a much more predator tolerant world, the pseudo species barriers that exist among wolves, coyotes, and dogs can break down. Hybridization among these creatures is likely to be a major feature of their continued evolution, a definite feature and not a bug.

These canids  thus make the leap with us into this human dominated age, an age that is experiencing a mass extinction of amphibians and great retrenchment of large sharks and big cats.

Yet they are still there. Evolving as the winds change. Winds that we ourselves are changing and are only now starting to understand.

Read Full Post »

Coyotes, nature’s sighthounds

Built a lot like a lurcher.

Read Full Post »

Why coyotes are not basal Canis

The traditional understanding of coyote evolution is that coyotes are basal wolf-like canids. This understanding comes from the hypothesis that coyotes directly evolved from Canis lepophagus in North America alone. Coyotes look and behave a lot like jackals of the Old World, and because we know that the larger wolf-like canids evolved from jackal-like ones, we just assumed that the coyote was a primitive form.

One problem with this positioning has always bothered me. Jackals tend to have proportionally smaller brains than wolves, but coyotes have proportionally larger brains than wolves. Domestic dogs have evolved smaller brains from wolves, although wolf and dog brain size comparisons aren’t as cut and dry as people think. 

No one thinks of dogs as basal forms of Canis, so it is possible for animals in this lineage to lose brain size, just as it is possible for a primitive lineage of canids known as coyotes to evolve a larger brain.

Please note that my discussion on brain size here isn’t really a discussion about intelligence, because the literature on which form is most intelligent is quite all over the map. Domestic dogs kept in Western countries in the modern way do appear to have social cognitive abilities that virtually all other species lack, while wolves are much better at working with each other to complete tasks.

But coyotes have proportionally larger brains than either wolves or dog do, and in this lineage, larger brains are generally a derived characteristic.

However, the really important data about coyote evolution is the discovery that they shared a common ancestor with gray wolves much more recently than commonly suggested. A genome-comparison study of various North American canids found that the common ancestor of both gray wolves and coyotes lived around 50,000 years ago. Because anatomically modern gray wolves replace the Mosbach wolf in the fossil record between 300,000 and 500,000 years ago, the ancestor of both had to have been a form of gray wolf from Eurasia.

The coyote is thus a jackal that has evolved in parallel out of the gray wolf lineage, which means it is not a primitive canid at all. It likely evolved this jackal -like morphology and behavior because the form of gray wolf that it derives from was unable to compete with the dire wolf, the American lion, the short-faced bear and the machairodonts as a top-level predator. It was forced to evolve a smaller body that could be fed on carrion and small prey.

We know now that there is a big difference in what prey predators target once they exceed 20 kg. Predators that weigh more than that mass target large vertebrates, while those that are smaller than that weight target smaller prey. Although coyotes do cooperatively hunt deer, they primarily feed on rabbits and mice. So by becoming smaller, coyotes were not directly in conflict with dire wolves or the other large predators of Pleistocene North America.

Only through analyzing full genomes of coyotes and gray wolves did we realize that our assumptions about their evolution were wrong. Earlier studies that looked at mitochondrial DNA alone found that coyotes fit within a basal position of the wolf-like canid lineage. However, recent full genome comparison of various wolf-like canids that looked at the role hybridization played in their evolution found something interesting. The lineage that leads to wolves, dogs, and coyotes experienced some introgression from a ghost species that was closely related to the dhole. The authors think that the reason why coyotes turn up so basal in these mitochondrial DNA studies but appear so wolf-like when their full genomes are compared is coyotes have retained a mitochondrial line that comes from that ghost species.

So the generalist coyote is a re-invention out of the gray wolf lineage. It is not basal to the wolf-like canids. It just merely resembles the basal forms in some of their ecology, in some of their behavior, and in their odd mitochondrial inheritance.

Read Full Post »