Wednesday, May 30, 2012

Leash Your Dog! – Another Coyote Update

It's been a few months since I last posted about the coyote carcass in our backyard. Decomposition has been going quite well, especially with warmer temperatures and a few days' worth of rain. The carrion beetles have been very active, and their larvae are eating the last of the remaining flesh. Still, there have been a few hitches along the way, in the form of a different species of canid: the domestic dog.

Sadly, there are irresponsible dog owners in the area, who do not believe in leashing their pets. Even worse, some folks simply let their dogs wander through the neighborhood, unattended, to do whatever they please, wherever they please. Unattended dogs often end up in our yard, sometimes just to defecate, and other times, to investigate the coyote. It's not something I'm happy about, and I wish more could be done to enforce the leash law.

A week or so ago, I went out back to survey our yard, and when I got to where the coyote should have been, it was entirely absent (despite having been there perhaps an hour before). I was both alarmed and concerned, and set out at once to locate it – surely a dog couldn't have dragged the whole body away without anyone noticing. It didn't take me long to find it: the coyote rested in a nearby driveway, about thirty feet from where it was supposed to be. Mostly bones, it was still held together by scant flesh, and I returned the carcass to our backyard. One of the back legs, however, was missing, and I doubt I'll ever see it again.

Not wanting a repeat of this incident, I placed a pallet, lined with window screening, over the body. This worked for a few days, until I saw that, yet again, a dog had visited, and had attempted to pull the coyote out from under the pallet. This time, it had made off with half of the pelvis and several tail vertebrae, which I'm sure are now long-gone. From four planks of wood and window screening, I constructed a more suitable decay-box; however, I had to pull the carcass apart, into four separate pieces, for it to fit underneath. On top of the decay-box I placed two heavy rocks. So far, this has worked.

This is what the coyote looked like this morning, after two days in a row of rain:

Predictably, the carcass is soggy and stinky, but these are great conditions for decomposition! Note the coyote's ghoulish, semi-mummified eye.

Ribs poke through decomposing flesh, catching the sunlight. I cannot stress enough how crucial this rain has been; the Upper Peninsula has been in a state of drought for years and years, and this particular spring has already been brutal. Last week there were two very large forest fires east of here, which together burned up tens of thousands of acres. Both are contained or near containment, and I'm sure the rain helped. Rain: good for plants, good for soil, and good for decomposition. All of these things are interconnected.

The right side of the coyote's head was damaged when she was hit by a car, and I have a feeling it was the impact against the pavement that did it. A few of her teeth are shattered, as is the back of her cranium. I look forward to seeing the skull in full, once the decay has finally finished.  

Note: Had a wild animal dragged the coyote away, I would be disappointed, but not angry. Scavenging is part of the natural world, and is, obviously, an integral part of this project's message. However, domestic dogs are not wildlife, nor do they belong in my backyard, so I do believe my exasperation and call for dog owners to leash their pets are justified. 

Another thing of note: In the winter, when the coyote carcass had flesh on it, it was visited by foxes, raccoons, and quite possibly a mink. The body wasn't once disturbed by dogs, as people don't typically let their dogs out for extended periods of time when it's cold. In contrast, when the flesh truly started to decay past the stage of edibility, wild animals left the coyote alone entirely.

Saturday, May 12, 2012

A Star-Nosed Mole

There are some animals that we don't know much about, due to their secretive behavior or remote habitat. Many of these mysterious animals live deep in the world's oceans, or in the thickest, most secluded part of the rainforest. But, if you can believe it, there are a few animals, right here in Michigan, whose habits biologists are still attempting to study and understand! One of those animals is the star-nosed mole (Condylura cristata).

I came across one, dead, a few days ago. It was lying upside-down on a bike bath, having only just died, probably less than an hour before. There was no sign of what had killed the mole, though it seemed to have a few puncture wounds in its back that were bleeding. Because moles are in the same order as shrews, I assumed that the mole had a bad taste that repelled its would-be predator. However, that assumption was false: star-nosed moles do not possess a bad taste or smell, so why the body was left remains a mystery.

Star-nosed moles are wonderful and bizarre in appearance. Their dark fur is dense and silky, and is water-repellant: which makes sense, as these moles live in damp habitats and can swim in pursuit of prey. The tail is long, scaly, and sparsely covered in thick hairs. The eyes are almost non-existent, and may be useful only for distinguishing between light and dark surroundings. The front feet have evolved perfectly over millions of years, and are amazing digging machines.

But, perhaps most bizarre and fantastic is the star-nosed mole's namesake: its nose.

This nose may well be the most sensitive, highly-developed nose in the animal kingdom. It is adorned with eleven pairs of tentacles – all of which can move independently – and each tentacle is covered with thousands of tiny sensory receptors called Eimer's organs. With this nose, the mole can effectively "see" its surroundings, in a way completely different than humans and most other vertebrates. It is perfect for detecting and catching the star-nosed mole's favorite prey: earthworms.

Star-nosed Mole II

After photographing the mole, I skinned it, and was amazed to see the structure of the head. The eyes were the size of poppy seeds, if not smaller, the snout was ridiculously long, and the teeth were tiny, sharp, and numerous. Unsurprisingly, the muscles on the forelegs were extremely well-developed.

Because star-nosed moles are so secretive, and their habitat doesn't usually intersect with gardens or lawns, they're not a common sight. I feel very fortunate to have found this animal! To see a star-nosed mole in action, watch this video. They are amazingly fast!

Thursday, May 10, 2012

A Tusked Squirrel

A few weeks ago, I received a handful of old taxidermy mounts that were no longer wanted at the Museum of Zoology back in Ann Arbor. All are in rougher shape, especially the fruit bat and the fox, and are quite likely full of arsenic. My favorite of the group, though, is a common fox squirrel with an uncommon appearance.

This fox squirrel had a nasty case of malocclusion when it died. Many species of mammals, including humans, can develop malocclusion, but it's the most dramatic with rodents: rodent incisors grow constantly, meaning they must gnaw constantly to wear down their teeth. When a squirrel has a cleft palate or a broken jaw (or is fed an improper diet its entire life), the incisors no longer align properly, resulting in overgrown, curled teeth.

In some extreme cases, the top incisors can grow so long that they pierce through the palate, and may continue back out the top of the animal's head. It's a miserable existence, and most rodents with malocclusion don't live for very long – pain and infections aside, it's hard to eat, and many die of starvation. One has to wonder if the taxidermist who mounted this squirrel – holding a nut it obviously could never eat – had a bit of a sick sense of humor.

This mount may have ended up in a dumpster, so I'm very happy to instead have it in my collection. It's bizarre, sad, and a wonderful example of how torturous Mother Nature can be.