Thirteen-lined ground squirrel

Appearance

It is brownish, with 13 alternating brown and whitish longitudinal lines on its back and sides, creating rows of whitish spots within dark lines.

Behavior

The thirteen-lined ground squirrel is strictly diurnal and is especially active on warm days. A solitary or only somewhat colonial hibernator, it often occurs in aggregations in suitable habitats.

In late summer, it puts on a heavy layer of fat and stores some food in its burrow. It enters its nest in October , rolls into a stiff ball, and decreases its respiration from between 100 and 200 breaths per minute to one breath about every five minutes. It emerges in March or early April.

The burrow may be 15 to 20 feet long, with several side passages. Most of the burrow is within one to two feet of the surface, with only the hibernation nest in a special deeper section. Shorter burrows are dug as hiding places. This ground squirrel's home range is two to three acres .

Its primary diet includes grass and weed seeds, caterpillars, grasshoppers, and crickets, but it may also eat mice and shrews; it will viciously attack and consume cicadas if able to catch them. This squirrel sometimes damages gardens by digging burrows and eating vegetables, but also devours weed seeds and harmful insects.

It is well known for standing upright to survey its domain, diving down into its burrow when it senses danger, then sometimes poking out its nose and giving a bird-like trill. The "trill" is an alarm call that is most often used by females to warn nearby relatives. It has a maximum running speed of 8 mph and reverses direction if chased.

The thirteen-lined ground squirrels have solitary habits, shown by agonistic behaviors to squirrels invading their own areas, which they've evolved, requiring less energy and the risk of getting injuired. Tail-flicking is also evolved from their solitary habits, which allows them not to violate other squirrel individuals' space.