I first took note of this phenomena a few years ago. Around fall, it’s like all of the sudden the squirrels somehow get a lot dumber and practically throw themselves under cars. This year it seemed to have started even earlier. My suspicion was that after a few good summer months of gorging themselves on garden bounty (such as every last piece of fruit in my yard!) they go into a food coma that slows them down to something approaching light speed.
Well in short, it’s not a food coma. I found this article in The Seattle Times describing the phenomena and even speaking to biologists who have dubbed it the “fall shuffle”. Food does play a part in the way of increasing squirrel populations if there is a good acorn harvest. If you’ve ever visited Portland in summer and fall you would know it is every greedy squirrel’s dream. More fruit and nuts than even these tiny bandits could possibly consume. Apparently while they are gorging all summer they are also engaging in more carnal delights and right about now there are a bunch of baby squirrels running around (After having read this article I did notice more babies around, their tails are much less bushy).
So the wee babes are running around (insert hilarious why did the squirrel cross the road joke here) getting picked off by cars on their quest for food. Even worse though, from the article:
Compounding the situation, squirrels are particularly active just after dawn and just before dusk, which coincides this time of year with morning and evening rush hours, a convergence that is bad news for squirrels.
That zigzag behavior, of course, is a defensive response to throw off predators.
But a car is another matter.