More On Ground Squirrels

Some of the California ground squirrels I see outside my window at work are now wounded. Only the males can be seen above ground; the females are all in their burrows, presumably with young.

The male nearest my window has some pretty serious injuries. They seem sequential, and also seem to have been the result of fighting, I’m imagining with other males. I have now seen quite serious lacerations to his neck, thigh, face, and now, today, a new one to the left hip.

There is quite a lot of research on ground squirrel communication, but from what I can tell it’s mostly on their calls. It’s an altruistic system: whoever’s on guard tells everyone else if there’s an aerial predator (a single, high call) or a ground one like a cat (a lower, multiple syllable one). Everyone wins in this system: if I save you today, you might save me tomorrow.

I wonder, though, whether there’s been much study of ground squirrel tail movement as communication. There’s clearly a significance in courtship-a waving tail means come hither by a female, essentially-but I’ve also noticed the males use their tails when threatening, and then abruptly turn to GROOMING their tails when they somehow both decide that this fight’s not worth it. (Owings does have a picture at the above link of side-to-side tail movement of squirrels approaching a rattlenesnake, and says this movement is restricted to this particular situation; we went to a fascinating talk where he explained how ground squirrels had developed an immunity to rattlesnake venom.)

Whatever the game might be, the male nearest my window is clearly losing; I think he might soon become food for Swainson’s hawk babies. One of the Wildlife Health Center vets took a look at his face through my binoculars yesterday (her diagnosis: “ooh, that’s gross”) and said she didn’t normally interfere when it seemed like natural behavior. She did say the wound was probably infected.

I watch him scratch the earth and rub the wound in it, worry it with his paws.

Migration’s almost over; I saw a warbling vireo yesterday, but no migrants today.