Ground squirrel one of county's interesting critters

It's among the most numerous of wild animals in Lake County but it doesn't have many friends. The California ground squirrel can be found at just about every location around the county. This little creature, weighing less than a pound, has an abundance of predators but still manages to survive and thrive.

Rattlesnakes, hawks, eagles, coyotes, feral cats and humans take a huge toll on this critter. Despite being considered vermin it is a fascinating creature.

Scientists have been studying the ground squirrel and they have discovered that they have a number of tools at their disposal to ward off predators. For example, they use their large tail to scare off rattlesnakes. Rattlesnakes locate their prey by sensing heat. They use a specialized sensory organ to detect the infrared radiation -- or heat signature -- given off by their small mammal prey. The squirrel pumps blood into its tail, which in turn increases the temperature in the tail and signals to the rattlesnake that it will defend itself. This display warns the snake that it has been detected and that it is likely to be harassed by the squirrel and others in the vicinity. The rattlesnake will usually leave the area.

Some squirrels have even developed immunity to the venom of a rattlesnake. The large tail also makes the squirrel look larger, which scares away predators. Female squirrels with pups also chew on the skins shed by rattlesnakes and then lick themselves and their pups (who are never immune to venom before one month of age) to disguise their scent from predators such as coyotes and cats.

According to scientists at 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 four 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 and each squirrel has its own separate tunnel. They live in colonies that can include several dozen animals in a complex of burrows. More than one squirrel can live in a burrow. They breed once a year and their litter averages from six to eight pups. The pups leave the nest in six weeks and are considered an adult when six months old.

The squirrels are active during the day, mainly from mid-morning through late afternoon, especially on warm and sunny days. They have two periods of dormancy during the year. During winter months most ground squirrels hibernate, but some young can be active at this time, particularly in areas where winters aren't severe. During the hottest times of the year most adults go into a period of inactivity, called estivation, which can last a few days to a week or more. During these periods, the burrow appears open at the entrance, but the squirrel plugs it with soil near the nest.

Ground squirrels do tame easily. A few years ago Jessie James, who used to live in Scotts Valley, rescued a baby ground squirrel and tamed it. He would call out its name and it would come running and jump on his lap. He kept the squirrel for several years until a rattlesnake killed it.

The reason ground squirrels are not very popular is because they do damage to plants and trees, especially nut and fruit trees. They also dig holes which can be dangerous to livestock. Squirrels also have been known to gnaw on plastic sprinkler heads. In addition, they will eat the eggs of ground-nesting birds such as quail. Ground squirrels also have been known to carry diseases such as bubonic plague. The Department of Fish and Wildlife (DFW) classifies ground squirrels as nongame animals, which means they can be killed without any restrictions. In some parts of California there are actually organized ground squirrel shoots where people will shoot the squirrels in a tournament-type event. Many people use a special poison to control the ground squirrel population. The poison is placed near the burrow and contains an anti-blood clotting chemical.

Whether you love them or hate them, the ground squirrel will be with us for many years to come.