|Squirrel bite marks|
(Stony Brook SP, NY)
Notice that it is a long stripe on the tree. The purpose of this biting seems to be to transfer scent from glands on the cheek rather than to feed. The bites themselves never make it all the way to the cambium layer. So what I was seeing on the branch in front of me was nothing like this. But I am no squirrel-marking expert so I was reluctant to eliminate any possibility. Finally, I felt it was possible that the bark was being collected as nesting or winter den material. The only flying squirrel nest I have ever seen was in a bluebird box and was completely made of shredded bark.
Look closely to see the individual incisor marks of the squirrels.
As for the WHO, I had several suspects in mind. I was pretty confident this wasn't a bird, but I considered woodpeckers. However, the wood was really not compromised at all as one would expect from a woodpecker. That left mammals and more specifically rodents (this just wasn't the work of rabbits). I was thinking gray squirrel since the are bigger and this was some big damage and the woods were primarily deciduous; the prime habitat for gray squirrels. I remember thinking Eastern chipmunk as well and as it turns out we never got a single image of chippies.
So our game of clue was upon us. Was it Professor Pileated with the candlestick in the library? Or Ms, Squirrel in the kitchen with a lead pipe? Time would tell.....
Here are the results:
First, the most images obtained were of mice. I never saw the mice engaged in any behavior that would account for the damage. It appeared they were using the log as a highway. I made a single composite photo of several mice just for fun:
But the second most common critter was the red squirrel. I didn't really consider this prime red squirrel habitat so I didn't really think of him as a suspect, but perhaps that is exactly WHY he was eating bark. In prime habitat, the red squirrel is eating pine seeds. I am under the impression that bark eating in squirrels is a sign that there is not enough of their preferred food. We had a very poor beech nut and acorn crop this year so maybe that had something to do with this behavior as well.
(Wayland, NY 10/12)
|Red and gray squirrel compared|
(Wayland, NY 10/12)