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Posts Tagged ‘Canada lynx’

woodland caribou

I had the pleasure of listening to Diane Boyd, a noted wolf expert, talk about wolf conservation issues on Steven Rinella’s Meatear Podcast. It is very good info about wolves, including wolf conspiracy theories.  One part I found particularly interesting was about the history of Isle Royale, which is experiencing a wolf reintroduction this year. Isle Royale is, of course, home to one of the longest running ecological studies that has examined predator and prey relationships.  The study mainly focuses on moose and wolves on the island, but an inbreeding depression reduced the wolf population of the island to two individuals last year.

I have always thought of Isle Royale as being a place of wolves and moose. But wolves came to the island only in the 1949, and moose came only in the early 1900s.

In the podcast with Diane Boyd, she mentions that Isle Royale was originally known for its woodland caribou and Canada lynx.  Boyd speculated that moose introduced brainworm to the caribou, but a more likely reason for their disappearance is that woodland caribou are sensitive to human-centered activities. All the logging and mining that happened on Isle Royale could not have done the caribou many favors. The last caribou was documented on the island in 1925.

Canada lynx are not particularly good predators of caribou. They were likely living on snowshoe hares, which are found on the island. Maybe, when snowshoe hares experienced the crash portion of their boom or bust population cycle, the lynx occasionally turned to hunting caribou, as they did in Newfoundland.

If Isle Royale’s fauna had remained the same at the beginning of the twentieth century as it did at the beginning, maybe it never would have become such a great place to study predator and prey population dynamics.

The restoration of wolves to Isle Royale, which is happening as I write this piece, is an attempt to bring back an ecology that dates all the way back to 1949. I have readers who can remember 1949.

We have this idea that conservation is about restoring things to an Eden when things were unmolested, untrammeled, and pure.  But what seems to be timeless is ultimately just temporary.

Last night, I was grappling with the concepts of conservation, specifically the idea of rewilding.  Rewilding is about restoring organisms to the land that were there at some point. Some think of feral horses in the West as being rewilded, from the Pleistocene though I am greatly skeptical of this idea.

Of late, though, there have been proposal to restore Pleistocene fauna to their former ranges, and if that animal can’t be found exactly, then a facsimile will be brought in.

In the case of North America, African elephants have been proposed as being equivalent of the Columbian and woolly mammoths. African lions might take the place of old Panthera atrox.   Some have even suggested that the plains of Texas, which are filling with blackbuck, might be a great place to turn out some cheetahs, thinking of course that Old World cheetahs are somehow the equivalent the long-legged coursing cougars that once roamed the Pleistocene wild of North America.

We don’t really know what killed off all these fantastic beasts of the Pleistocene. I lean more toward rapid warming at the time of the Pleistocene/Holocene boundary, but many reasonable people find some merit in Paul Martin’s “Overkill Hypothesis.”  This hypothesis contents that the Siberian hunter-gatherers who came into North America wound up killing off much of the megabeasts, or lacking such evidence of profligate killing, contend that these hunter-gatherers killed off a few keystone species, such as mammoths and mastodons, to cause ecosystems to collapse.

If this hypothesis is correct, there is a moral force for this Pleistocene rewilding concept. Humanity is responsible for killing off the megabeasts, and it is our duty to restore North America to its former glory as the land with the great bison, pachyderms, camels, and equines.

But this takes me back to Isle Royale. Humans certainly disrupted that ecosystem. If we wished to restore Isle Royale to its form ecosystem, we should be shooting off all the moose on the island and turning out woodland caribou from Ontario. We shouldn’t be trapping wolves and turning them loose. We should be trapping Canada lynx instead.

Canada lynx are much rarer in the Upper Midwest than gray wolves are, so by a triage of the conservation needs of the species, it would make more sense to preserve Isle Royale for the lynx.

Of course, that’s not what is being done. The wolf and moose studies are too deeply ingrained in our science and our understanding these two species. And if you were to twist my arm, I’d say choose wolves and moose over caribou and lynx.

But this is logic of Pleistocene rewilding. It is to say that we can somehow turn back the clock on that happened long before North America had cities and agriculture and way long before the continent was divided into nation-states.

Indeed, while we’re theorizing about Pleistocene rewilding, we’re not really coming to terms with that fact that Pre-Columbian rewilding is a project that will only go so far. Yes, we’ll have wolves come back to the Upper Midwest and the Western States.

But no one is seriously considering restoring grizzly bears to Texas or even attempt to bring back wolverines to Michigan.

We cannot handle that idea of wildlife now. That we have managed to hold onto so many wild places and restore so many wildlife species is a certain greatness about the United States. However, this feature is one that always exists in tension, one that must be recognized and fully understood.

Isle Royal in 2019 is not the same as Isle Royal in 1960, which was not the same as Isle Royale when the loggers and the miners came.

And if that one island is so different, imagine how different the entire continent of North America has become since the Pleistocene gave way to the Holocene, which has now giving away to the Anthropocene.

There is a sadness in knowing that things pass, and we certainly have a moral duty to prevent extinction and to preserve what ecosystems we can.

But we should understand that what we’re preserving was never timeless, and even in our attempts at restoration, we aren’t always going back to the known original condition of a place. We often go back to what seemed wondrous and pure and wild.

And if we can understand this simple fact, maybe we can get a handle on what our species continues to do to the planet and the rest of life that resides here with us. We have done much, but we shouldn’t assume that we are preserving any kind of stasis.

I write these words from the northern edge of Appalachian Ohio, awaiting the arrival of the nine-banded armadillo, which will some day come working its way up from North Carolina and Tennessee into Virginia and then West Virginia.  Xenarthan,  the “strange jointed stranger”  with roots in Latin America, it will come scurrying along into this part of the world.

What it may change in our ecosystems, I cannot guess. But it is coming.  When it arrives, it will roam where wolves once howled and elk bulls bugled.

And its story on the land will be one to note. It will not be timeless. It will a temporal as the fleetingness of existence, a bit of the faunal guild of the Anthropocene making a name for itself in a new land, just as those Siberian hunters did all those thousands of years ago.

 

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Snowshoe paws

Canada lynx (Lynx canadensis) have really big feet. They are snowshoe hare specialists, and these big paws help them move over the snow, just like snowshoes.

They are not just boreal bobcats. They are derived from a much latter migration of Eurasian lynx into North America, while the bobcat likely evolved from endemic North American lynx. They adapted to living in snowy climates, and because snowshoe hares are often abundant, they became specialists at hunting them. Their numbers follow the boom and bust cycle of snowshoe hares throughout their range.

 

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canada lynx

North America has two species of lynx, the widespread bobcat (Lynx rufus) and the boreal-adapted Canada lynx (Lynx canadensis). The two species do have some range overlap across the northern-tier of states, and when Canada lynx ranged down the Appalachians, their range overlapped much more extensively.

These two animals behave quite differently from each other. The bobcat is a generalist predator that hunts everything from mice and voles up to white-tailed deer, while the Canada lynx specializes in hunting snowshoe hares.

The bobcat is found in Mexico and throughout the southeast, especially in Florida.  Those southernmost bobcats are often not much larger than domestic cats, but the biggest bobcats, which are found in the Great Lakes states, are actually larger than Canada lynx.

It is well-known that bobcats and Canada lynx do hybridize. Hybrids have been produced in captivity, and hybrids have been encountered in Maine, New Brunswick, and Minnesota.  These hybrids are apparently fully fertile, which leads to the question of how much the two species really do hybridize.

A group of researchers looked into a big sample of bobcats and Canada lynx that came from across the continent. Of the 2,851 cats sampled, only 7 had any evidence of introgression from one species to the other.

This finding shows that bobcats and Canada lynx do hybridize, but it is virtually unknown in the wild. The authors caution that if Canada lynx numbers ever become low, bobcat introgression could swamp the genetics of that population, effectively making the species disappear through hybridization.

This finding is quite different from what has been discovered with gray wolves and coyotes. Gray wolves and coyotes have apparently exchanged genes across North America, and animals of mixed coyote and gray wolf genetics are pretty common.

Because we don’t have evidence of a hybrid swarm, which we do with wolves and coyotes, we have very good evidence to consider bobcats and Canada lynx quite distinct species.  And conversely, it is within reason to question the validity of coyotes and gray wolves as being distinct species

I would love to see a similar study to the genome comparisons performed on gray wolves, coyotes, and admixed canid populations in North america performed on Canada lynx and bobcats. My guess is that there will be some evidence of very limited hybridization between the two species, but it will not be like coyotes and gray wolves.

We don’t have a good handle on when bobcats and Canada lynx last shared a common ancestor. We need some more genomic data to make this claim, but what we know now is that Canada lynx and modern Eurasian and Iberian lynx are sister taxa.

The bobcat is thought to be more basal to the lineage.  Lynx species have been roaming North America since the Pliocene. Indeed, the earliest lynx fossils were found in North America, not Africa, as we previously believed.

The bobcat evolved in North America. It is the last survivor of the endemic North American lynx that gave rise to the other species in Eurasia, while the Canada lynx came back from that ancestral Eurasian lynx population some 200,000 years ago. 

These animals have likely been distinct from each other for a very long time, but they have not yet lost chemical interfertility. It will likely be a while before this happens, but if climate change continues to threat Canada lynx populations, the bobcat will move north into their range and hybridization could become a threat.

So stay tuned to see what happens, but the genetic data clearly show that bobcats and Canada lynx are two distinct species that do rarely hybridize.

 

 

 

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canada lynx

For many years, there was a bit of debate about how many Lynx species there were. In the 1980s,  the Canadian lynx and the Eurasian lynx  were thought to represent a single species.

The Canada lynx is not a northern bobcat, as one might think. These cats are very similar to each other in size, and it actually gets quick touchy trying tease apart historical accounts of bobcats and lynx in North America.

But bobcats come from earlier invasion of the Lynx lineage that came into North America between 2-5 million years ago. The Canada lynx came about when an ancestral Eurasian lynx came into North America within the past 200,000 years. The Canada lynx is more closely related to the modern Eurasian lynx than to the bobcat.

Compared to the bobcat and Eurasian lynx, the Canada lynx is a bit weird. Eurasian lynx and bobcats are very much generalist predators. The Canada lynx is a super specialized predator. They pretty much live on snowshoe hares alone, and their populations track the snowshoe hare population cycles. It is pretty weird that this animal has hitched itself to such a tenuous prey species.

One could make the case that the Canada lynx is nothing more than a specialized Eurasian lynx, even though it is significant smaller.

I think this is a bit hard to justify. For one thing, there is absolutely no gene flow between Eurasian lynx and Canada lynx, except in captivity. Canada lynx, bobcats, and Eurasian lynx all can interbreed and produce fertile offspring, but unless the Bering Land Bridge appears again, there is no way for Eurasian lynx to arrive to hybridize with them.

I also don’t think there is any way to get around the super-specialized body of the Canada lynx, which is long-legged and big-pawed. It’s also a lot smaller than the Eurasian lynx.

So I think it is hard to get around the simple fact that this animal is distinct enough to be a species, even it can hybridize with bobcats and Eurasian lynx.

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A perfect pet, eh?

I wonder what happens when you try to take his chicken away.

Source.

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Source.

One dead moose sure can feed a lot of creatures!

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Edwardian-lynx-c-Bristol-Museum-Art-Gallery-600-px-tiny-April-2013

Ab4458 the Edwardian lynx. Photo (c) Bristol Museum & Art Gallery. From Tetrapod Zoology.  

An errant Canada lynx was killed in the English county of Devon in 1903.

Darren Naish writes in the Tetrapod Zoology blog:

For over 100 years, a potentially significant dead cat has been sat in storage in a British museum. Specifically, the specimen – the lynx Ab4458 – has been at Bristol Museum and Art Gallery ever since it was added to the collections there in February 1903, and what makes it significant is that it was shot dead after living wild in Devon, southern England. As revealed in a new paper published by Aberystwyth University’s Max Blake and a team of colleagues (myself, Greger Larson, Charlotte King, Geoff Nowell, Manabu Sakamoto and Ross Barnett), the specimen represents a historic ‘British big cat’, though with ‘big cat’ being used very much in the vernacular sense, not the technical one (Blake et al. 2013).

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For over 100 years, a potentially significant dead cat has been sat in storage in a British museum. Specifically, the specimen – the lynx Ab4458 – has been at Bristol Museum and Art Gallery ever since it was added to the collections there in February 1903, and what makes it significant is that it was shot dead after living wild in Devon, southern England. As revealed in a new paper published by Aberystwyth University’s Max Blake and a team of colleagues (myself, Greger Larson, Charlotte King, Geoff Nowell, Manabu Sakamoto and Ross Barnett), the specimen represents a historic ‘British big cat’, though with ‘big cat’ being used very much in the vernacular sense, not the technical one (Blake et al. 2013).

A lynx of any species would not technically be a big cat. The term “big cat” in the taxonomic sense applies only to the cats in the genus Panthera (the tiger, the lion, the jaguar, the leopard, and now, the snow leopard) and the two species of clouded leopard. All other cats are technically “small cats,” which means that the cougar, the largest of the small cats, is actually larger than the smallest of the big cats, the mainland clouded leopard.

This particular lynx caused quite a stir before it was it was killed.

Accession documents at the museum describe how it was shot dead by a ‘Mr Heb’ (the handwriting in the accession catalogue is difficult to read and this name might be wrong) after killing two dogs. It was then donated to the museum by a Mr J. Niblet of Newton Abbot, Devon. The geographical origin of the specimen is given as ‘Newton Abbot’. Foreign specimens are clearly marked with a place of origin, so we have to conclude that the cat really did come from Devon.

No one really paid much attention to this cat until 2011, when Max Blake, a student at the University of Bristol, found it while doing volunteer curatorial work at the museum. The animal was quite clearly not a Eurasian lynx, as everyone had initially assumed.

Blake, who was then studying zoology, knew it either had to belong to one of the two New World species of lynx, the bobcat or the Canada lynx.

But the animal appeared to have a mixture of both Canada lynx and bobcat features. The cat had just enough facial markings to suggest that it was a bobcat, and thus, it could have belonged to one of the northern subspecies of bobcat.

When I initially heard of this case back in 2011, I thought it was a northern bobcat, not just for those reasons, but because it is virtually unheard of for a Canada lynx to attack dogs. Bobcats, however, are much more aggressive animals, and in the wild, the larger subspecies are known for hunting mule and white-tailed deer. Canada lynx are rangier than bobcats, but they are actually lighter in weight than the largest subspecies of bobcat. And their diet consists of almost nothing but snowshoe hare. (Canada lynx are about the most bizarre cat species I can think of).

The researchers were unable to extract any DNA from the specimen, but the museum did still have its bones on file. After a careful morphological analysis of its skull, it was determined that the cat was indeed a Canada lynx.

This lynx had very worn out teeth, which suggests that is was of advanced age when it was killed. It also might explain why it was so willing to attack the dogs. It was desperate for some sort of sustenance, and dogs may have been the only suitable prey available.

Analysis of the teeth revealed it likely hadn’t been living on its own for very long:

Examined with all of this in mind, Ab4458 lost its incisors during its lifetime. New bone then overgrew the alveoli*. Thick build-ups of calculus are present on its lower and upper premolars. Based on this data, we conclude that Ab4458 suffered from periodontal disease and – based on all that calculus – lived a life of 10 or 11 (or so) years in captivity during which it fed on soft, non-abrasive foods. In conclusion, we couldn’t find any evidence here that the animal lived for a long time in the wild. Rather, it had been a captive animal for years (Blake et al. 2013).

So someone in Devon had been keeping a pet lynx for quite some time. It then was either released or got loose when it was about 10 or 11 years old.

My guess is this cat came from Newfoundland. Devon and Dorset were the English home counties for a large number of fishermen who fished off Newfoundland’s Grand Banks.  Newfoundland English is heavily influenced by the dialects from that part of England, where the people sound like stereotypical pirates.

Perhaps a Devon fishermen brought home a lynx kitten for his children as a souvenir from his travels. The cat was probably a beloved pet for a few months. Then maybe it got a bit aggressive, and its owners moved it to the backyard, where it remained for the rest of its life.

Until it escaped or was set free.

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