Cold Decay

Spring may have officially started one month ago, but that doesn't mean much in Michigan's Upper Peninsula — especially not this year. In 2012, we experienced a spring unlike anything I've ever seen before: 80°F temperatures, early flower blooms, and little snowfall to speak of. This year has been the exact opposite. We've had snowstorm after snowstorm and weeks of daytime temperatures barely scraping 32°F; now, in what's getting to be late April, spring looks like it might finally be on its way. Maybe.

Toward the end of March, I put the head of the Ann Arbor buck outside, and tied it to a post: I had the hope that the chickadees, nuthatches, and bluejays would scavenge at it. Well, the birds saw it, gave it a few suspicious looks, and promptly ignored it — and the buck head has been hanging there, relatively unchanged, ever since.

 

Once the temperatures hit the mid-50s and 60s — and stay there — the beetles and flies will no doubt discover this food source and consume it quite quickly. I do still hope that the birds, at the very least, will use the fur to line their nests. I witnessed some of that behavior last spring, when I was stretching a deer hide, and it was neat to see the chickadees and warblers stuff as much fur as possible into their tiny beaks.

Despite the sky being gray and the temperatures not exceeding 40°F, the snow is melting — slowly. Much of our backyard is still covered. I did see an old friend today, though, thanks to the work of an off-leash dog. Last October, I picked a raccoon up off M-28, skinned it, and later put the body out back. At some point in late November I checked in on it, and was surprised to see maggots squirming around beneath the corpse. We received our first substantial snow in mid-January or so, and the raccoon has been covered ever since — until today.

 

The body's state of decomposition was quite putrid, with meat and fat sloughing off the bones. In some places, mold had started to grow, and it came in a vast array of colors, ranging from pink to white to blue. The off-leash dog had really torn into the carcass — and I've observed this, time and time again: (wild) scavenging mammals want nothing to do with carrion when it's in this state. Domestic dogs, however, seem to love it.

In any case, because spring has been slow, posting has been slow. I hear that temperatures might actually reach the low-60s this weekend, and maybe by mid-May the snowbanks will have melted.

From the Collection: Fisher Identification

This is a Fisher (Martes pennanti) skull:

It should not be confused with an American Badger (Taxidea taxus) skull:

... or a Raccoon (Procyon lotor) skull:

Fishers are a large member of the weasel family, Mustelidae. An uncommon and shy animal, they are agile tree-climbers and prefer coniferous forests. Fishers are well-known for being one of the very few predators of porcupines! They also prey upon snowshoe hares, squirrels, and other small mammals, and are known to eat carrion. Despite what their name suggests, fishers do not seek aquatic meals.

Here is another view of the fisher skull. Note the canine tooth was not quite fully erupted at the time of the animal's death:

And, a closer look at that canine tooth:

This is an interesting skull — the rest of the teeth appear to be adult teeth, fully grown-in. Some of the nasal sutures are fused, and the sagittal crest, while small, is still rather well-developed. It's possible that the canine tooth was just late in appearing, a pathology unique to this particular individual.

A fisher skull should not be hard to identify. Shape and size aside, there is an easy-to-find feature that is unique to this species' teeth:

The upper molar, second from the back, has an exposed "rootlet". No other animal skull of similar size or shape possesses this same characteristic. Nevertheless, fisher skulls seem to get confused with those of raccoons and badgers, at least in my experience.

As you might remember from the previous post about the badger skulls in my collection, they were a case of mistaken identity: the shop owner swore that they belonged to fishers. Here's a side-by-side comparison of the two:

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Though fishers and badgers both belong to the weasel family, their appearance, habits, and skulls are quite different! The badger skull is larger and stockier; the fisher skull is thinner, with an overall more delicate appearance. While badgers are digging, burrowing animals restricted to the ground, fishers are skilled climbers and possess retractable claws.

When I purchased this fisher skull, it was misidentified as that of a raccoon. Shown together, they are quite different in shape, as well:

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Again, the fisher skull is longer, thinner, and flatter than the stocky, domed raccoon skull. Raccoons, like fishers, are dexterous climbers, but their omnivorous diet is far more varied — hence the not-so-sharp teeth of the raccoon.

For good measure, here is a side-by-side comparison of the raccoon and badger skulls, as these two are often confused, as well:

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Badger and raccoon skulls are actually pretty similar in appearance! But raccoon skulls are smaller, and badger skulls have a more "square" profile. Raccoons are not mustelids, and instead are part of a family that includes coatis and ring-tailed cats.

I've never seen a live fisher in my travels, and likely never will — they are a very wary animal. I came very close, however, last summer: Steph and I were backpacking along Pictured Rocks in Alger County, and near the beach we discovered the fresh tracks of a fisher:

 

It was likely that the fisher had been there no more than half an hour before us. Despite searching extensively, we never found the owner of the tracks.

Mink Feet

For an animal so seldom seen, the American Mink (Neovison vison) seems to get hit by cars quite frequently. One reason for this may be that roads often follow and cross the paths of rivers and streams — prime mink habitat. I've seen several roadkill minks over the years, but haven't spent time photographing any until now. Last year, a mink was found dead in the road, downstate, and was brought to me. Today, I took a few minutes to photograph it — just the feet, as the animal's head had been crushed by a tire.

 

 

A Dead Animal Sampler

I am currently visiting my family in Ann Arbor! Unlike Marquette, there's no snow on the ground and the daytime temperatures are above freezing. The cardinals and red-winged blackbirds are singing, and with the springlike weather, many mammals are on the move. It was made painfully apparent, as on my way down US-23, I saw that the highway was littered with their corpses.

This morning I took a drive to the Matthaei Botanical Gardens for some shed antler hunting and general scavenging. I wasn't let down!

One of the first finds was an Eastern Cottontail. There wasn't much left to the rabbit's body — it had been preyed upon, likely by a coyote or a fox. All that remained was fur and its back feet, one of which I photographed, in-hand:

 

It's an interesting play on the concept of a "lucky rabbit's foot" — which, as it turns out, is a custom that has been around for thousands of years! Obviously, this cottontail wasn't so lucky, but the predator that fed upon it was.

The next find wasn't a dead animal — it was an antler!

 

Finding shed antlers is always exciting. I was able to spot this one from around fifty feet away, as it was an arc of gleaming white in the dull, dead grass. It's got four tines, and is of average size. It's also freshly shed — and there are no rodent gnaw marks! This find, however, was dwarfed by my next discovery.

As I looked for this antler's mate, which I never found, I noticed a turkey vulture circling overhead. I started off in that direction, and was soon met by an incredible sight:

 

This White-tailed Deer buck was a relatively recent death — likely no more than a few weeks old. His vitals had been ripped open by coyotes; his stomach contents were bared to the sky and his pink muscles glistened. The buck's eyes were mostly intact, but for whatever reason, his nose and ears had been bitten off by coyotes. One leg was missing entirely. His antlers, though, were pretty amazing.

 

Three tines on the right antler were broken, likely during the rut. The same antler also had some neat little kickers coming out near the base, as well as an unusually wide main beam. The tines on the left antler, including the eye guard, were quite long.

 

Back in 2011 when I found March Buck, I had needed assistance in removing his head — this time, I was more than capable of doing it myself! As I cut it off, the turkey vulture circled overhead, patiently waiting for me to leave. This buck's head will be returning with me to Marquette; it will be interesting to see how old this deer was. I'm unsure of his cause of death — it's possible he was struck by a car, then limped into the field to die.  

My adventure didn't end there, however. The next find was a small Striped Skunk, found dead in the same field. It looked to be only a day or so dead. It's very possible that the skunk died of rabies; I left the body alone and continued on my way.

 

After dropping off the (very heavy) buck head and shed antler in my car, I continued to explore. Deciding it might be interesting to see if March Buck's skeleton was still there, I headed in that direction. I didn't find any of his bones — but I did find the carcass of a doe. She was laying in almost the exact same place that I found March Buck: beneath the lone cedar tree.

 

The doe's state of decay was nearly identical to that of March Buck. But even stranger — and this was downright uncanny — was that she, too, had something wrapped around her foot. Unlike March Buck's piece of plastic tubing, this doe had a guy line strangling her hind leg, just above the dew hooves. It had tightened all the way down to the bone — which was broken.

 

I have little doubt that this impairment caused her death. It was a disturbing, grisly sight.

At that point, I started the long trek back to the parking lot. Along the way, I spotted the body of a Virginia Opossum beneath a tree:

 

It was a relatively small animal, and looked to have been dead for at least a week or so. In typical opossum fashion, the lips had curled away from the teeth, making for a gruesome, deathly grimace.

My last find of the day was the lone foreleg of a deer.

From the Collection: Badgers!

Winter still has its icy, snowy grip on Michigan's Upper Peninsula, so back to the collection we go! Today's topic is the American Badger, Taxidea taxus — not to be confused with the oft-erroneously represented Eurasian Badger, Meles meles, nor the internet-famous Honey Badger, Mellivora capensis.

Like the minks* from the previous collection post, the badger is also a member of the weasel family, Mustelidae. Striking facial markings aside, however, the badger is quite different in appearance from most mustelids. Its body is flat and stocky, and its skull is stout and raccoon-like. Badgers have shaggy fur, a short tail, plenty of loose skin, and long, sharp claws for digging. They carry a fierce reputation, but they are also shy creatures. Unlike the Eurasian Badger, the American Badger is a rather solitary animal; it prefers open grasslands for its habitat. Its southeasterly range does not extend much further than Michigan, but the badger thrives in the prairie and desert habitat to the west and southwest.

I have two American Badger skulls in my collection. Both came from the same source — a taxidermist's shop in the Keweenaw Peninsula. I have a feeling that mammals were not his strong point: he swore the skulls belonged to fishers (Martes pennanti)**, and that "he shot them himself." Neither was professionally cleaned, and they look as if they sat outside for a number of years. With cracks and missing teeth, neither skull is in great condition, but they were only a few dollars apiece, and both have character.

The first badger skull belongs to a middle-aged individual. Though the skull has a strong sagittal crest, the sutures on the rostrum were not yet fused at the time of the animal's death. Obviously, this badger met its end by being shot in the head. Bullets, just like the tire of a car, do an incredible amount of internal damage, and seldom does a bullet leave just a clean, circle-shaped hole in its wake:

The reverse side of the skull shows a gaping hole, though this is not quite as dramatic as the skull's ventral view:

In addition to the cracks spiderwebbing along the braincase, the force of the bullet blew out a large portion of the skull's underside. It's a very quick, violent way to go; it's most likely the badger was trapped and then shot at close range.

The second skull, though missing two of its canine teeth, is in better condition than the first:

 

This skull came from a much older animal. Though its teeth were not in bad shape at the time of its death, its sutures are completely fused. It's a more robust skull than the first, and measures 5.0" (as compared to the bullet-damaged skull's 4.75").

Here are a few side-by-side views of these two badger skulls:

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Lastly, here is a photo showing the size difference between last entry's mink skull and a much-larger badger skull:

* The identity of the second mustelid skull from the previous entry has not yet been confirmed! There have been a few guesses but the mystery still remains. If you haven't already, share the link with someone who knows their mammals well!

** The fisher will be the next skull I showcase. It, too, was the victim of mistaken identity!