The window of my office looks out on a patch of lawn about thirty by fifty feet. In the middle of the lawn there’s a live oak tree. This oak tree appears to have produced a bumper crop of acorns this year. This afternoon, I counted at least six Eastern Gray Squirrels (Sciurus carolinensis) on the grass, the surrounding sidewalks, or in the tree; three of them were the black color morph of S. carolinensis.
The squirrels have been digging furiously in the lawn, and in a few places have completely dug up all the grass, leaving a network of small holes about two inches across and one inch deep. Every so often, one squirrel will get too close to another one, which can lead to vocal squabbling and one squirrel chasing another. I also saw at least three American Crows (Corvus brachyrhynchos), who would land on the grass periodically and peck at the ground where the squirrels had been digging. Sometimes a squirrel would run at a crow; and the crow, even though it was somewhat larger than the squirrel, would flap its wings a couple of times and fly out of the way.
Amy and I were watching the squirrels a couple of days ago. “If they would only get organized,” said Amy, “they could run all us humans out of here and take over.” Of course she was exaggerating, but they are aggressive. They have come right into my office while I’ve been sitting at my desk with the door open, looking for food. It’s worth noting that since Eastern Gray Squirrels have been introduced to the Bay area, the native Western Gray Squirrel (Sciurus griseus) has essentially be extirpated from the region.
I went over to look at the damage the squirrels had done to the lawn. There is nothing in the holes they have dug. The ground is littered with the outer husks of acorns; some of the husks look green and new, some look brown and old. There are plenty of new acorns on the ground. I’m not sure why they are digging so furiously this year; this is not something they have done in past years. Maybe there’s a good reason behind it, or maybe they’re just — well, maybe they’re nuts.