Thursday, April 24, 2014

Porcupine Places and Parts

This post might be only for the naturally curious as it touches on scat and dead things, specifically that of porcupines. When I am out and about in woods, wetlands, and fields, I often see the remains of animals that died naturally or were killed by a predator or vehicle (roadkill), as well as signs of footprints, poop (aka scat), or other features.

Of course it is usually more exciting to see a live animal in its natural habitat, but many mammals are secretive or active only at night, so live sightings are uncommon. Signs of their activity or their demise are much more likely. And these signs tell a lot about an animal's behavior and characteristics, which brings us to the porcupine.
Porcupines leave lots of sign of their activities. Since they are active mostly at night, we don't often see them in action. Porcupines are slow and have poor eyesight, which leads to many getting killed on roads. Against most potential predators, a porcupine's 30,000 quills provide an adequate defense. Dogs know this well, although they never seem to learn. A few animals--including the fisher--are adept at exploiting a porcupine's quill-free zones: its face and belly.
Winter is the best time to see signs of porcupine activity, as they leave several tell-tale signs: pigeon-toed tracks in well-worn trails in the snow, piles of scat at their den entrance, and clipped hemlock branches beneath a favorite tree, as seen in photo below.
This behavior is called "nip-twigging." A porcupine perched high in a hemlock in winter, clips a small branch to reach the buds and new, tender needles at the very tips. The rest of the needle-covered branch is dropped to the ground as waste. However, a white-tailed deer finds these fallen hemlock boughs just fine for a winter meal.

As noted, porcupines are unlike most other mammals in that they defecate at the entrance to their dens. On Saturday I visited a very large den site with so much scat that the entrance was blocked.
Just outside this den site we found a dead porcupine, whether killed by a predator or just died we don't know. There wasn't much left but a few parts.
Take another look at the picture above, the one that shows a necklace-like string of, well, porcupine scat. This is the desiccated lower intestine of the dead porcupine filled with individual pellets yet to be expelled. Apparently whatever killed the porcupine or fed on it after it died, was not interested in eating the scat-filled intestine, which is all plant material. (Porcupines are 100% vegetarians, make that vegan.) I had never seen this before, so it was a great find (for those that get enthused about such things). Thanks to Vermont naturalist Mary Holland for confirming the answer to "what is this necklace?"

Porcupines are giving birth about now to one porcupette. The quills on a young porcupine harden within a few hours after birth, giving it ready protection against potential predators, except when it tries to cross a road.

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