Squirrels: Frenzied, But Not Teething

March 22, 2015 at 10:53 am | Posted in Brain and mind | 4 Comments
Tags: animal behavior, mammal

An Eastern Grey Squirrel (Sciurus carolinensis) in St James’s Park, London, England. Photo by DAVID ILIFF. License: CC-BY-SA 3.0 .

A previous post asked for an explanation of a puzzling frenzy that squirrels exhibit each Spring and Fall. Thin new twigs of trees rain down upon the ground. Each twig has been bitten off by a squirrel, who then apparently immediately drops it without even nibbling it. Since there is a new crop of baby squirrels each Spring and Fall, the post had hypothesized that this vandalism was committed by teething baby squirrels. It asked observant readers to post as comments anything they observed that confirmed or refuted that hypothesis, and also to post any explanations that they knew of, or alternative hypotheses.

Twigs that had been chewed off by squirrels and unceremoniously dropped. Photo by thepoliblog.WordPress.com.

The Spring frenzy started up at our house about two weeks ago, and it provides a partial answer.

There are no baby squirrels yet. So the rain of bitten-off but uneaten twigs cannot be due to the teething of baby squirrels. It is due to bezerk adults.

But what drives the adult squirrels into this frenzy?

In the Spring, all of the bitten-off twigs are new, and bear clusters of buds. But the frenzy is not due to squirrels being tickled or startled by the new twigs, because there are no new twigs during the Fall frenzy.

Are the twigs bitten off as a metaphorical chest-thumping by horny male squirrels?

Are they bitten off only by pregnant squirrels?

The twigs are not bitten off for nest-building, because the bitten-off twigs are all allowed to fall to the ground, where they are allowed to remain indefinitely.

Spring Break doesn’t seem to be a likely explanation, unless squirrels also have a Fall Break.
This explanation is additionally implausible because beer pong is considered to be beneath the dignity and intelligence of any squirrel.

The relevant Wikipedia article states that, ” To sharpen their teeth, squirrels will often chew on tree branches or even the occasional live power line.” Is that why they are biting off the new twigs? No, because if they were doing it to sharpen their teeth, they would not also do it in the Fall, I think.
If you spot a potential answer to this mystery, please post it as a comment below.

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