Up in the north country of Michigan – north of the so-called Bay City/ Muskegon line – porcupine road kills are about as common as possum kills “downstate.” Because of their naturally slow nature (top speed about 2 miles per hour) and nocturnal habits, porkies frequently find themselves failing to make to the other side of the pavement. Porcupines also happen to have a thing for salt and in their constant search for sodium they often resort to pavement licking for residual road salts. Needless to say, this practice is even more unsafe than your plain variety crossing habit. I’m not sure if it was saltiness or slowness that resulted in the collision that ended the career of the porcupine I picked up the other day along M-30 outside of West Branch (see here). I was appreciative, never-the-less, of the opportunity to get a good close look at one of these unique forest beasts.
As a Naturespeak reader I invite you to peek over my shoulder as I perform the examination. How does one go about probing a porky, you ask? Of course you know that the answer is “very carefully”. It’ll take two installments to do this right, so please stick with me (pun intended).
A majority of the features of this common creature are very uncommon indeed. They are, of course, the only quill bearing mammals in the region, but we’ll get to that in due time. There are many distinctive non-quill features to look at first. Porcupines are the third largest rodent found in the Americas and the second largest in Michigan behind the beaver. On average they span around 30 inches from head to tail and tip the scales at around 14 pounds. I wasn’t able to weigh my example, although it felt like a ten pound bag of potatoes…or should I say a ten pound box of nails! This creature has an overall body type like that of the beaver with a round head, no neck to speak of, large hindquarters, and a thick tail (see below). It’s hard to see their actual outline due to the dense covering of long stiff hairs that extend beyond the quills- some of which are 4 inches long. Most of the underfur is black, the quills are white, and the “true” hairs are reddish brown. There is a patch of short black fur, bordered by a forest of white quills, that runs in a chevron shaped pattern down the back and along the entire top side of the thick tail.
The face is flat and covered with short black hair. With small eyes and short and rounded ears (see beginning photo), it’s no wonder that this fellow is nearsighted. Given the fact that “pines” communicate with a host of squeals and teeth grinding it is reasonable to assume that they hear relatively well. Porcupines are all about scent communication, so possess a large nose and prominent nostrils to probe their scent-filled world. You may find it re-assuring that my road-kill example gave off absolutely no scent what-so-ever – good or bad. This was a very fresh little pig!
I found the feet to be fascinating. In fact, I would say that you haven’t really lived until you’ve shaken hands with a porky (see below). There are no quills on the lower legs so it’s safe to handle these appendages. Porcupines are flat-footed, which in the parlance of mammalogy classify them as plantigrade beasts. This means that they walk on their soles in the manner of bears, raccoons, and humans. Most other critters walk on their toes. Their tough sole pads have the look of pebbly gray plastic and the feel of a vinyl chair seat. There are four well-clawed toes on the front foot (see here) and five on the hind foot (see here). These claws work in unison with the pliable sole pads to allow this hefty beast to climb trees. The tail is also used as a brace much in the manner of a woodpecker to keep from backsliding. We all want to keep from backsliding don’t we?
Oddly enough, porcupines are prone to falling out of trees. Many show signs of healed bone fractures sustained from such accidents. In one study, over 30% of the examined quill pigs had suffered from fractures. On this note, you might have noticed the neat little puncture hole in the sole of the hind foot pictured earlier. This was likely caused by a self-inflicted quill wound. Yes, porcupines often poke themselves with their own weapons of defense. That pointy topic will have to wait until next time.