March 16, 2012
We have another new sighting for the North Campus. A California ground squirrel has been spotted using the opossum den located underneath one of our Museum sheds. So far it seems that both the opossums and the squirrels are sharing the space!
Sam Easterson's camera trap captures the first image! This is what Jim Dines, our Mammalogy Collections Manager, has to say about them: The California ground squirrel, as its name suggests, is common throughout California as well as the rest of the western U.S. Scientists know this rodent as Otospermophilus beecheyi (formerly known as Spermophilus beecheyi). They are diurnal (active during the daylight) and, like other ground squirrels, live in burrows that they excavate or take over from other animals. Our ground squirrel has apparently moved into a den built by an opossum. Ground squirrels eat seeds, nuts, and a variety of other plant material, as well as insects and handouts left by humans. Since they also invade gardens and cultivated areas, California ground squirrels are commonly regarded as pests. Their extensive burrow systems can be very destructive. They are also a host to fleas that can carry plague, so pose a health risk to humans and their pets. Rattlesnakes are one of the main natural predators of California ground squirrels and the squirrels have developed an interesting defense mechanism: the ground squirrels will eat the shed skins of rattlesnakes and then lick themselves and their young, thus covering themselves with rattlesnake scent and confusing a potential rattlesnake predator into thinking it is merely smelling another rattlesnake. Pretty sneaky, eh? The California ground squirrel has a fairly bushy tail so is sometimes mistaken for the Eastern fox squirrel (a tree squirrel), but has different colored fur and retreats underground instead of up into a tree. Watch Sam accidentally startle the squirrel into the den!