Squirrel is the common name for rodents of the family Sciuridae. In everyday speech in the English-speaking world, it usually refers to members of the genera Sciurus and Tamiasciurus. These typical members of the family are tree squirrels with large bushy tails.
They are indigenous to Europe, Asia and the United States. Similar genera are found in Africa. The Sciuridae family also includes flying squirrels, and ground squirrels such as the chipmunks, prairie dogs, and woodchucks. The unrelated family Anomaluridae also have “squirrel” in their common name. They are usually referred to as “scaly-tailed flying squirrels”.
Typical squirrels include the European Red Squirrel Sciurus vulgaris, the Fox Squirrel S. niger, the Eastern Gray Squirrel S. carolinensis, the Western Gray Squirrel S. griseus, the Douglas Squirrel Tamiasciurus douglasii, and the American Red Squirrel Tamiasciurus hudsonicus.
Diet and feeding behavior
One well-known trait of some species of squirrel is the gathering and storing of nuts for the winter. They will gather juicy nuts and store them in any accessible hiding place, usually by burying them. Recent research shows that they have rather limited memories, and use spatial clues to remember the locations. Ground squirrels rise on their hind legs and curl their paws flat against their chests when they sense any kind of danger. They will then survey their surrounding territories. If they feel that they are in danger, they will often send the warning call. It is a loud screeching sound, to alert other squirrels.
Unlike rabbits or deer, squirrels cannot digest cellulose. They must rely on foods rich in protein, carbohydrates, and fat. Early spring is the hardest time of year for squirrels. Buried nuts begin to sprout and are no longer available, but new food sources have not become available yet. During these times squirrels rely heavily on the buds of trees, such as the Silver Maple. Despite popular impression, squirrels are actually omnivores. They also eat a wide variety of plant food, including nuts, seeds, fruits, fungi, and green vegetation. Also, they eat insects, eggs, and even small birds, smaller mammals, and frogs. It is also a common occurrence that these foods replace nuts in some of the tropics.
Squirrels are sometimes also pests because they chew on various edible and inedible objects. The habit helps keep the squirrel’s teeth stay sharp and also wears them down (rodents’ teeth grow continuously). Homeowners in areas with a heavy squirrel population must keep attics and basements carefully sealed to prevent property damage caused by nesting squirrels. Squirrels can be trained to be hand-fed. Because they are able to collect surplus food, they will take as much food as you put out. If a person starts to feed one, that squirrel will come back often. Urban squirrels have learned to get a great deal of food from generous humans.