Tree squirrel

Tree squirrels are members of the squirrel family known as Sciuridae.

While they are often just called "squirrels," they do not form a single natural group. Instead, they are related to various other animals like chipmunks, marmots, and ground squirrels. The term "tree squirrel" is based on their habitat rather than their physical traits. These animals live mostly among trees rather than in burrows in the ground or among rocks. There are more than 100 arboreal species found on every continent except Antarctica and Oceania.

One fascinating exception to the standard tree squirrel body plan is the flying squirrel. Although it lives in trees, it possesses a unique physiological feature called patagia. These are special flaps of skin that act like glider wings. This allows the animal to perform gliding flight between trees. Most other tree squirrels rely on expert climbing skills to move through their environments. Many species have also adapted to live in human-altered areas like suburban backyards and urban parks.

Scientists use genetic data to classify tree squirrels into several distinct subfamilies. One major group is the subfamily Sciurinae, which includes the genus Sciurus. This genus contains well-known animals like the North American fox squirrel and the Eurasian red squirrel. Another group is the subfamily Callosciurinae, which consists of Asian tree squirrels. This group includes the genus Funambulus, such as the Asian palm squirrel. The Asian palm squirrel was introduced to Australia in the 1920s.

Other subfamilies include Ratufinae, which contains the Asian giant squirrels, and Xerinae, which includes African tree squirrels.

Squirrels have a very specific way of interacting with their environment through gnawing. Their teeth grow continuously throughout their lives. Because of this, they must chew on objects to prevent their teeth from over-growing. This characteristic trait means they will gnaw on many different things to keep their teeth sharp. They may chew on tree branches, plastic, or even metal to reach food. This persistent behavior can sometimes make them a nuisance to humans.

For example, they may chew through bird feeders or garden items to find snacks.

In residential areas, squirrels can cause significant property damage and safety concerns. They build nests, which are called dreys, in places like attics, basements, and sheds. These nests can cause unpleasant odors, noise, and structural damage to a home. A serious risk involves electrical systems. Squirrels often treat exposed power cables like tree branches and gnaw on the insulation. This can lead to short circuits, power outages, or even fires. In fact, squirrels have been responsible for shutting down the NASDAQ stock market twice.

Humans have had a long and varied relationship with squirrels. In Western society, squirrels were kept as pets until at least the 19th century. They were especially popular with the clergy and women due to their small size. Historically, squirrels have also been hunted for food and fur. In the Middle Ages, the red squirrel was hunted for its blue-gray winter coat, known as vair. In the Southern United States, squirrel meat was a traditional ingredient in Brunswick stew.

Today, some people in the UK eat the invasive gray squirrel as a fashionable meat option.

While squirrels are often seen as pests, they are also part of the urban landscape. In many cities, squirrels have become desensitized to humans and can be hand-fed in parks. However, wildlife experts note that feeding them improper foods can be harmful. For instance, sunflower seeds and peanuts can lead to metabolic bone disease because they lack essential nutrients. In some areas, people even build special structures like the Nutty Narrows Bridge in Washington to help squirrels cross busy streets safely.