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Archive for the ‘Carnivorans’ Category

My sister ran into this Hawaiian monk seal in Maui today!

hawaiian monk seal

There were three species of monk seal: the Hawaiian, the Caribbean, and the Mediterranean. The Caribbean monk seal is now extinct, and the remaining two are pretty rare. The Hawaiian has some issues with an inbreeding depression, so it’s a pretty cool thing to run into.

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A red fox vixen in the Mid-Atlantic part of the USA. Photo by Kris Diaz.

A red fox vixen in the Mid-Atlantic part of the USA. Photo by Kris Diaz.

Red foxes are currently the most widespread wild canid.

This is the same sort of fox that can be found in Egypt, England, and Virginia, and it has been introduced to Australia, where it has become a virulent invasive species, taking out scores and scores of endemic native wildlife.

For many years there was a debate about how to classify the red fox in North America. Unlike Australia, where there is no real case for calling it native wildlife, North America’s red fox population has been a bit controversial.

When the tobacco colonies along the Chesapeake created America’s first landed gentry, there was a move to import well-bred foxhounds for sporting purposes. At that time and in that part of the continent, there were no native red fox populations, so there were accounts English red foxes being introduced to the Virginia Tidewater and the Maryland plantations for sporting purposes.  Red foxes were found in northern New England at the time, so I’ve often wondered why they didn’t just get their foxes from those colonies.

For a very long time, it was just assumed that red foxes living south of New York State were derived from English foxes that were brought over in the seventeenth and eighteenth centuries.

After all, the Australian red foxes were definitely derived from introduced individuals, so it would make sense that there could be an introduced population in the Eastern US.

However, red foxes are found over much of the continental US and Canada, and there are Pleistocene records of red foxes in Virginia.

So red foxes definitely are native to this continent, but the question is whether those in the Eastern US are derived from native populations or from those English imports.

In the early twentieth century, virtually all red foxes in North America were classified as Vulpes fulva, rather than Vulpes vulpes.

But as time progressed, all North American red foxes became classified as Vulpes vulpes, and the Eastern and Midwestern population of red fox became Vulpes vulpes fulva.

Then two papers came out that examined the DNA of red foxes across the continent and in Europe.

In 2012, Stratham et al.  found that their mtDNA of Southeastern and Mid-Atlantic red foxes was very similar to those in Eastern Canada and the Northeastern US, meaning those populations were indigenous North American foxes. They descended from foxes that came into that part of the continent during in the nineteenth century in much the same way coyotes invaded the East in the twentieth century.

Then, in another Stratham et al (2014) paper, it was revealed the Old World and New World red foxes have been reproductively isolated for 400,000 years. This paper also looked at the y-chromosomes and nuclear DNA of 1,000 red foxes from around the world, and it strongly suggests that there are actually two species of red fox. There was some evidence of Eurasian red foxes entering into the Alaskan red fox population 50,000 years ago, but other than that, these two animals might as well be separate species.

Now, I’m a little hesitant to consider that red foxes should be split in two in this fashion, but keep in mind, that in North America, there are two species of Urocyon fox, the mainland gray fox and the island fox. But analysis of mtDNA from both types of Urocyon revealed that the island population only split from the mainland species somewhere between 7,100 and 9,200 years ago.

The lower estimate of that split is at least half the time that dogs and wolves have been split.

And it’s nowhere near the time in which New World and Old World red foxes have diverged.

If we are so willing to have two species of Urocyon, then there is way that we can have just one species of red fox.

The case that these two types of red fox are different species is just so much stronger than the island fox’s taxonomic distinctiveness.

Of course, I actually do question the taxonomic validity of the island foxes. Some of these island fox populations are so inbred that they could stand to have mainland gray foxes introduced for genetic rescue purposes, but because they are a species in the eyes of the Fish and Wildlife Service, no one seriously considers the possibility.

But when it comes to red foxes, two things are clear:

They are native to this continent and are not English imports.

And they haven’t exchanged genes with the Old World red foxes in a very long time.

So there really is a strong case that our red foxes are Vulpes fulva and not Vulpes vulpes.

But there aren’t wide morphological differences between the two populations. Red foxes in Europe pretty much look like the red foxes of the Eastern US. In fact, North American and northern Eurasian red foxes look much more similar to each than either looks like the Middle Eastern and North African subspecies of red fox.

Red foxes in Eurasia and North America pretty much share the same niche as generalist mesopredators. Both types have successfully colonized suburban and even urban environments.

Those are the traits we see.

But their DNA says we’re looking at two quite distinct populations.

It’s counter-intuitive.

But it is strangely fascinating.

 

 

 

 

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Bobcat poo turns chalky white when it gets old. There is a lot of calcium carbonate in the feces, which means they turn chalky when left exposed for a few days.

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Too cute fox!

Look at that face!

Source.

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This week we had several visitors on the trail cameras. Keep in mind that one of these cameras has a messed up clock, so the time stamp reads that the video was taken in 2068. These cameras are pretty good technology, but they aren’t that good!

Let’s start small.  Here’s a white-footed mouse or a deer mouse:

Source.

I can’t tell whether it is a white-footed mouse or a deer mouse, which is hard enough to do in the broad daylight. These animals are in the genus Peromyscus, and although we call them mice, they aren’t closely related to the mice that originated in Old World.  New World rats and mice are more closely related to voles, hamsters, and lemmings than to house mice and Norway rats.

Then we got a light-colored opossum:

Source.

A good close-up of a melanistic gray squirrel:

Source.

And a large raccoon:

Source.

Because of the size of the raccoon, I am assuming that this one was a male. He was coming to inspect a pile of sticks and logs that I have anointed with weasel lure.

 

 

 

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Source.

The uploader of the video describes the fox as a “silver fox.”  This isn’t correct at all. This is a gray fox, genus Urocyon, which is not a true fox at all.  It is actually the most genetically distinct species of dog still existence today. It last shared a common ancestor with the rest of the dog family 9 to 10 million years ago.  Gray foxes are known for their tree-climbing behavior, which is one of their hallmarks. Indeed, another name for this fox is the “tree-climbing fox” or “tree fox.”

Silver foxes are actually a phase of red fox. When I first watched the video, I was expecting to see a silver phase red fox, but the shrieks very quickly told me that this uploader had misidentified the species. This is pretty common. Silver and normal phase red foxes do interbreed, but you might as well try to cross a red fox with a hamster than try to cross red and gray foxes.

A fisher is a large North American marten. North American martens are not closely related to Eurasian martens, but they look similar to them. In fact, both North American marten species are more closely related to wolverines than to pine and beech martens which they superficially resemble. The term “fisher” comes from a mistranslation of the French word for polecat, which is fichet. French trappers sold fisher pelts as polecat pelts, and the name just sort of got stuck with them. They don’t fish at all. They hunt porcupines and squirrels and have been known to take white-tailed deer fawns on occasion.

The fisher’s range is currently expanding. They are now becoming more and more common in the Eastern US, and in my state, where they were extirpated, they are now making a strong comeback.

They live in pretty much the same habitat as gray foxes and hunt a lot of the same prey, so I have actually been thinking how these two species would interact. My guess is they would be hot competitors, and this video suggests that I might be right. I don’t know if there are any studies on fisher and gray fox interactions, but as fishers expand their range deeper in the gray fox’s core range, there will be lots of interactions like this one.

The “lesser” carnivora don’t get much attention as the big ones do, but their behavior and ecology are every bit as fascinating.

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Bounding weasel

Weasels bound, so they make tracks that look like two little feet. But what really happens is they put their front feet down and then move their back feet into the same place where their front feet were as they bound forward.

My guess is this was a least weasel, because it was awfully small.

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This weasel likely came through just before it started to snow yesterday, because its tracks are nearly filled in. There was a whole line of tracks just like these going from one side of the access road to the other.

 

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