One of the most common wild animals in Lake County is not the deer, bear or mountain lion, but the California ground squirrel. Just about every empty lot or field in the county has a healthy population of these little critters. The ground squirrel is also a valuable food source for just about all the meat-eating predators such as coyotes, bobcats, foxes, possums and raccoons. Scavengers such as eagles and hawks also seek out the tasty ground squirrel. In addition to predators the ground squirrel is a popular target of humans who shoot them. Every year there are several sanctioned ground squirrel shoots throughout California.
According to the University of California, ground squirrels live in a burrow system where they sleep, rest, rear young, store food and avoid danger. The burrow openings are about 4 inches in diameter but can vary considerably. The burrows can be 5-30 feet or more in length and can extend 2-4 feet below the surface. Often there is more than one opening in a burrow system. Ground squirrels live in colonies that include several dozen animals in a complex of burrows. More than one squirrel can live in a burrow. They are seldom seen outside their burrows except to run from burrow to burrow.
Ground squirrels breed once a year, averaging seven to eight per litter. Timing of breeding varies with location. In Lake County, that time is February through April. Above-ground activity by adults is at a maximum at the height of the breeding season. The young are born in the burrow and grow rapidly. When they are about 6 weeks old they usually emerge from the burrow. At 6 months they resemble adults. They can live up to six years but most won’t make it past four.
They are most active during the day when they can be seen out foraging on plant seeds and even plant roots. They are primarily herbivorous and their diet changes with the season. After emerging from hibernation, they feed almost exclusively on green grasses and herbaceous plants. When annual plants begin to dry and produce seed, squirrels switch to seeds, grains and nuts and begin to store food. Ground squirrels usually forage close to their burrows. Their home range typically is within a 75-yard radius of their burrow.
They are very alert and are constantly on watch for hawks and eagles. Another one of their predators is the Great Blue Heron. Often as you drive the back roads in Lake County you will see a blue heron standing very still by a hole in the ground. He is waiting for a ground squirrel to show himself. It’s not unusual for a heron to stand by a hole for several hours and then, with a quick jab of his bill, grab the squirrel and swallow it. A few years ago I spent at least four hours watching a blue heron in a field near Lakeside County Park. During that period he grabbed two squirrels and swallowed both.
The most interesting aspect about ground squirrels is their relationship with rattlesnakes. Rattlers prey heavily on ground squirrels but over thousands of years the squirrels have developed a defense system against the snakes. Their long, bushy tail isn’t designed to keep them warm as some believe. It’s actually a defense mechanism they use to scare off a rattlesnake. The large bushy tail makes them look larger to the snake. They also pump blood into the tail, which creates an infra-red signal to the snake and makes him miss his strike.
The Department of Fish and Wildlife classifies ground squirrels as a non-game animal, which means they can be taken at any time of the year with no limit.
Many people classify the squirrels as pests because of the burrows and holes they make in their yards. Actually, they are another fascinating animal that makes living in Lake County so special.
