So does the maned wolf break the “costs of carnivory” paradigm?

In recent post I wrote about the new research regarding the thylacine’s size, I mentioned that maned wolves might violated the “costs of carnivory” rule, which states that predatory mammals that weigh more than 21 kilograms (46 pounds) must haunt larger prey sources to survive.

Maned wolves do exceed this size, but their diet does not consist of large prey. They are not a threat to ungulate livestock. They take only small prey, such as rabbits, rodents, and small birds. They could be a threat to chickens and other poultry, but they aren’t cattle killers.

On a superficial reading of their ecology and diet, one would assume they would break this 21 kilogram rule. The largest ones do get to around 23 kilograms, and if they are that large, then they surely break this “costs of carnivory” rule.

But they don’t.

The reason is they have a most unusual diet for a canid.  Between 40 and 90 percent of their diet can consist of a single fruit called a lobeira or “wolf apple.” The average diet of a maned wolf is around 50 percent vegetable matter, which means they aren’t as bound by the rules of carnivorous diets as other mammalian predators are.

The maned wolf first appeared in the fossil record in what is today the Desert Southwest what is called the Blancan faunal age (late Pilocene to early Pleistocene).

It entered South America, along with a whole host of other canids, and it evolved to a specialist niche as a grassland predator. Many species of similar-sized dog were also diversifying in South America, it is likely that it evolved its unusual diet as a way of avoiding competition with more carnivorous canids.

So vegetarian are maned wolves that when fed a typical wild carnivoran diet in zoos, they often develop bladder stones. Their kidneys cannot absorb a particular amino acid called cystine, and the excess cystine turns into stones.

Most mid-sized canids are true generalists in their diets. The exceptions are the maned and Ethiopian wolves. The Ethiopian wolf runs between 14-19 kilograms, so its rodent specialized diet does not violate the rule.

But the maned wolf’s heavily frugivorous almost takes them out of the predator guild entirely.  They are as almost omnivorous as most bears are, and all extant bear species exceed 21 kilograms at maturity.

So maned wolves don’t violate the costs of carnivory rule. They do so, because they are far less predatory than virtually any other dog species. They are certainly less predatory that other dogs of their size.

T

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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.

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Multiple cryptic species of jaguarundi?

One must be very careful using studies of mitochondrial DNA to make conclusions about the natural history of animals. The DNA is inherited matrilinearly. It does not follow the entire genetic legacy of an organism.

However, it can point to the possibility that our understanding of taxonomy is incorrect, and these studies have pointed to multiple cryptic species in what we once thought was only a single one. Gray foxes and black-backed jackals have deep divergences in mitochondrial DNA lineages in populations that are not contiguous, which suggests that there are more species than the single one currently recognized.

Of course, these findings do require more study to figure out if these divergences are reflected in the nuclear DNA. But these studies are just the beginning.

Recently, I came across this paper from PLoS ONE that was published 2017. It looked the mitochondrial DNA of the jaguarundi, a neotropical cat that is most closely related to the cougar. It does range into the United States, but it hasn’t been seen here in decades.

This species has been a bit of problem for molecular biologists, because it is been quite difficult to figure out subspecies. There is little correlation between mitochondrial DNA sequences and morphology, which has made classifying them quite difficult.

But the authors discovered a rather unusual discovery. Using calculations of mutation rate, they found that the two main clades of jaguarundi diverged 3.2 million years ago. The same metric found that jaguarundis and cougars diverged 3.9 million years ago, and the divergence between the two clades of jaguarundi happened earlier than the divergence between lions and common leopards and the divergence between the tiger and the snow leopard.

This discovery does suggest that there at least two species of jaguarundi, which are morphologically indistinguishable.  Of course, the authors make it clear that more evidence from nuclear DNA needs to be included in the analysis, but the discovery does suggest that our classification of the jaguarundi as a single species may be faulty.

 

 

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Can African cheetahs replace the now defunct population of Asiatic cheetah in India?

India’s supreme court is now seeing an interesting case in which taxonomy and endangered species politics converge to have real world consequences. The question is whether African cheetahs can replace Asiatic cheetahs on India’s plains.

Yes, for there were once cheetahs in India. Their traditional quarry was the blackbuck antelope, and many nobles in India kept cheetahs or “hunting leopards,” as the British colonizers called them, for coursing blackbuck.

Cheetahs were not just found in India.  They ranged throughout the Middle East up into the Caucasus and Central Asia. In the wild, this lineage of cheetah is found only in Iran, where they exist in only relict numbers.  In Iran, the situation is made even more complicated with an international human rights scandal in which several cheetah researchers were imprisoned.  Cheetahs have since been extirpated from all of Asia, except for that tiny Iranian population.

So India, a nation with growing wealth and a growing conservation ethic, cannot turn to Iran to reintroduce its former cheetahs.  With Iran out of the question, some experts have suggested that African cheetahs be used as stand-ins.

And this is where things get interesting. African cheetahs are not exactly like the ones in India. There is a bit of a debate about when the two lineages of cheetah split, with one set of papers and researchers suggesting a very recent split (5,000 years ago) and another suggesting a more ancient one (44,000-47,000 years ago).

40,000 years suggests way too much evolutionary distance between the two cheetah populations for African cheetahs to be equivalent of the Asiatic ones.

But even if we accept this later date, it is still not that much of a divergence. Currently, most experts recognize only a single species of red fox, but Old World and North American red foxes diverged 400,000 years ago.

African cheetahs have evolved to hunt on open plains. Various small antelopes comprise the majority of their diet. They are not ecologically that different from cheetahs that lived on the plains of India.

So they aren’t that genetically distinct from each other, and they aren’t ecologically that different either.

It would make sense to bring African cheetahs to India. Of course, the legal system and the interpretation of statutes often goes against sound conservation policy.

But if cheetahs are ever to return to India, the question is now in the hands of India’s supreme court.

I hope they decide that those from Africa can stand in. They are far from exact, but they are far from ersatz.

 

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Orphans of the Disused House

Life and death act out their forces on nature and man. And so it went with this old house. No one lives there any more. The lawn has grown thick with meadow grasses and multiflora rose, and no one seems to remember much about who lived there or the dramas of existence that played out within its walls.

But one would be wrong to think such an edifice would be without life. Two orphaned raccoons, both brothers, wound up commandeering the premises one sweltering hot July evening.  Their mother had been crushed on the highway. She darted out just as a massive semi came racing down the lane, and she was exited this mortal coil in a loud thud and the whirring of tires upon bone and ligament.

They were well-weaned when she was killed, and they spent the better part of the summer learning to be proper raccoons. They negotiated the lazy streets and moved onto quite country lanes, where garbage was sometimes illegally dumped.  They avoided the barking dogs and the murderous boar racccons. They bluff-charged cats and swatted away slobbering opossums.

For weeks, they meandered about, but one day, the came across something quite nice. One a quiet country lane, an old house stood.  And to the curious young raccoons, it was a beacon. It was like finding an island full of hidden treasure. It smelled so interesting and so beguiling.

Weather had worn down some siding near the front door. All it took was a bit of chewing and pulling, and the two brothers had made themselves a good entry hole.

Upon entering the house the found it full of old tables and chairs and couches from the time Gerald Ford was president.  Scores of insects, including beetles and moths, had taken up residence in the house, and these creatures were a welcome nighttime repast for the two brothers.

A fox squirrel had made her nest in the attic, and her four little babies also were a nice snack, but after going through the house in search of food, the two brothers realized they had stumbled upon a true treasure.

Most raccoons den up in trees. A few unfortunate souls use burrows that were dug by other creatures.  Some raccoons do well in old barns, and countless ones have taken up residence in chimneys.

Normally, those that choose to live in human created structures find themselves evicted pretty quickly, but no one cared about this old house. A car might pass by the structure twice or three times a day, usually the crotchety old man who lived at the end of the road. He would curse about the eyesore had to pass when journeyed back to civilization, but he wouldn’t do anything about it. He would just motor on in disgust and go on with his day.

So the two brothers had found themselves a raccoon castle, and for the rest of the summer, they used it as their retreat. At night, they would make sorties into true dwelling civilization, and by morning, they would be at home in the old house.

And so through the summer, the two brothers lived well in their castle, but this situation could not go on forever. They could not know that the coming winter would bring on the rut, the great war between the boars. They could not know that someday they would be tearing at each other’s faces.

But for now they curled up beside each other as the sun cast down into the smudgy old windows. The light it cast in the house was ethereal. Ancient dust rose into the beams of light, casting about like some forlorn glitter.

They snuggled into each other as the hissing of dog day cicadas buzzed out from the adjacent walnut trees.  The youthful summer was now, and they could thrive and wallow in it.

But just as all things with man and nature, the summer of peace would be fleeting on.

But in youthful raccoon existence, there is no time to think of such matters or even to consider them. That something is temporal is not even understood.

And so they slept in the bliss of the current hour as if it were all that lay ahead. To be is to be, and one must be right now and not in the horrors of the coming future.

They were young raccoons in that state of ignorant bliss, a state our kind secretly admires though publicly disdains as if we all didn’t know the real truth.

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A potential new species of wildcat discovered on Corsica

Wildcat taxonomy is hotly contested, especially with the 2017 revision of the taxonomy of Felidae, which posits that the wildcat of Africa, the Middle East and South and Central Asia is a different species from that of Europe and the Caucasus.

The island of Corsica, once home to many insular endemic mammals during the Pleistocene, has always had a legendary wildcat, one that farmers claimed was a predator of goats and other livestock.  However, it was debated about whether this cat was a European wildcat or just a feral cat.

However, in recent days, various outlets have reported that a team of scientists is now examining this cat more closely.  Its DNA is different from the mainland European wildcat.

One hypothesis is that these “fox cats” arrived with the second human colonization of Corsica, which would put it closer to the ancestor of domestic cats than to the European one.

The current thinking is that this Corsican fox cat is a new species, but more analysis is going to be performed before anyone can make that conclusion.

If this animal arrived with people and is derived from the Middle Eastern population of Felis lybica, then it is a feral cat. However, it is a different sort of feral cat than one finds in parking lots and old warehouses.

This discovery will take a lot more work to figure out fully what it is. It may be a new species of cat, or it may give us better clues on how cats were domesticated.

It is an amazing find, and I have so many questions. And they will likely be answered in the not to distant future.

 

 

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Baby trash pandas

I took the trash out this evening, and I discovered a litter of trash pandas hanging out by the bin. I did not see the mother, but they did run when we realized we weren’t to be trusted.

We did not touch them.  I hope their mother is nearby. If I see them out tomorrow, I will be calling the DNR.

 

 

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Doug Peacock and Grizzly Bears

Posted on The Atlantic’s Youtube channel, this week:

He’s one of my heroes. I won’t lie about it.

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The Eastern brown bear

The brown bear of North America is usually called a grizzly bear, but it is part of a species that once ranged across the Northern Hemisphere from Ireland to Kentucky.  Yes, at the end of the Pleistocene, this species expanded its range through a broad swathe of North America. This eastern population apparently did not exist into historic times, for the first accounts of these bears are all from early explorers entering the West or the Great Plains.

But there was a population of brown bears that lived on in the East until historic times. This population was not documented fully, though, until it was extirpated.

In Northern Quebec and Labrador, there were always accounts of anomalous bears that went on into the twentieth century.  Farley Mowat documented much of this evidence in Sea of Slaughter, and the most compelling evidence in Mowat’s text is an off-line by George Cartwright in which he describes a bear with a white ring around its neck. This is an accurate description of a brown bear cub.

However, Mowat was aware of a discovery of a female brown bear skull on Okaka Island by anthropologist Steven Cox.  The find was buried in an Inuit midden, and from this discovery,  it has become accepted that brown bears lived in Northern Quebec and Labrador until the twentieth century. This form of brown bear is sometimes called “the Ungava brown bear,” but no one has attempted to give it a scientific name, simply because it was probably an Eastern extension of the grizzly bear population.

This bear was probably killed off for its hide and because it caused great conflicts with people.

This brown bear, though, was the last brown bear of Eastern North America. It has never been clear to me why the brown bears of Ontario, Michigan, Ohio, and Kentucky became extinct. It usually said that brown bears prefer more open habitat than black bears do, but brown bear live very nicely in forests on the West Coasts and in Europe.

We do know that Native America populations in the East were fairly dense, and if these late Pleistocene-early Holocene bears were as much a problem to live with as grizzly bears can be, it would make sense that humans would have extirpated them from their settlements.

But the truth is we really don’t know why the brown bear became extinct from its eastern range. It did, however, hold on in the far reaches of Quebec and Labrador until about a century or so ago.

 

 

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How to classify the domestic cat?

As I have noted many times on this blog, I think that the only way to correctly classify the domestic dog is as form of gray wolf. I am okay with regarding them as a divergent subspecies, but Pierotti and Fogg make a pretty good case that we really cannot define a domestic dog subspecies, because that subspecies would have to include everything from truly feral dogs to pekingese. I think that the wolf genome comparisons also show that creating a special dog or dingo species distorts the monophyly of Canis lupus.

Some will argue with me on this one, but you will have to use a species concept that is totally not based in cladistics or one that allows for a huge amount of gene flow between the two species.  An ecological species concept can work, but then you’re going to be forced to split up Canis lupus into many different species. Arabian wolves are simply aren’t ecologically equivalent to arctic wolves. So I think creating a special dog species is problematic from a systematics perspective.

However, I’ve been asked several times what I think about how to classify the domestic cat. Almost every authority in cats uses the name Felis catus to describe the domestic cat, while Canis familiaris is slowly being replaced by Canis lupus familiaris.

The revised taxonomy of Felidae  that was released in 2017 does change how we classify wildcats. Classically, we recognized a single species of wildcat, Felis silvestris. The domestic cat is derived from a Near Eastern population, which was classified as Felis silvestris lybica.  There was another wildcat that lives Western China that was sometimes recognized as Felis sivestris bieti or Felis bieti. The big taxonomy debate in this genus was where to include this Chinese mountain cat into the greater wildcat species or have it be a species of its own.

The new taxonomy changes quite a bit of this. Felis bieti is now recognized as species, but Felis silvestris now refers to only European and Caucasian wildcats.  Felis lybica is the new scientific name for the wildcats living Africa, the Middle East, South Asia, and some parts of Central Asia, where it is sympatric with the Chinese mountain cat.  The fact that lybica and bieti exist in the same area without much gene flow is apparently the reason for elevating bieti to a species.  The reason for splitting up silvestris, though, had do with a deep mitochondrial DNA divergence between European and Caucasian wildcats and the rest of the wildcat species. Apparently, these two forms split from each other 173,000 years ago.

This revised taxonomy is really, well-supported with data, and I generally think it is right in its conclusions. However, I do think it made an error with this genus.

It retained Felis catus as a full species.  The same logic that says dogs are Canis lupus familiaris says that you cannot have a special domestic cat species either.

So the best way to classify domestic cats is as Felis lybica cata. You will probably only see this name written on this space, because unlike the literature on dogs, there is a noted deep adherence to Felis catus in the literature on domestic cats.

I honestly don’t know why there is such an adherence, because domestic cats are not that different from Felis lybica.  They come in more colors and coat types, but most domestic cats can live just as wildcats do. That’s why feral cats are an ecological hazard in so many places. They are quite effective predators, the ultimate mesopredator that found a niche living under the nose of man.

We don’t have as many good nuclear DNA studies on the various small cats as we do on various forms of the gray wolf complex, and this may be why there is a tendency to avoid a cladistic classification for the domestic form.

But if we’re doing this for dogs– and for good reason– we should be doing the same for cats. And the same for pigs and domestic mallards and domestic jungle fowl.

 

 

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