SCALY-TAILED SQUIRRELS – Anomaluridae

SCALY-TAILED SQUIRRELS

SCALY-TAILED SQUIRRELS FACTS

The scaly-tailed squirrels range in size from 7.3 to 18.5 inches (18.5 to 46 centimeters) along their head and bodies, with tail length measuring between 5.4 and 18.4 inches (13.8 to 45 centimeters). They generally weigh between 7 ounces and 4 pounds (200 to 1,800 grams). The family Anomaluridae (from words meaning “strange-tailed”) look very much like regular squirrels (family Sciuridae) from the outside because they have adapted to similar environments, but major differences in their skulls, teeth, and other internal items show that they have no close relationship. Scaly-tailed squirrels, unlike regular tree squirrels, have a furred “gliding membrane” on each side of their bodies that stretches in a square shape between the front legs and the back legs and also between the hind legs and the tail. Only one genus, the mainly diurnal (active during the day) Zenkerella, lacks this membrane and cannot glide. The membrane is supported in front by a strut-like, rigid section of cartilage that extends from the elbow joint, rather than from the wrist, as in the true flying squirrels. They are the only gliding mammals in Africa. Scaly-tailed squirrels are so named because of the double rows of overlapping, spiky scales on the underside of the tails for one-third of its length along the base. When the animals land after a glide, the scales help to keep them from skidding on tree trunks, and also help them climb up trees. Their silky tails are bushy on top and have strongly colored tufts. They have strong digits for manipulating food and climbing, and very long whiskers and large ears for their mainly nocturnal activity. Their heads are large and placed forward on the face, providing excellent binocular vision for finding prey and good landing places.

GEOGRAPHIC RANGE

Scaly-tailed squirrels are native to the middle region of Africa, and live mainly south of the Sahara Desert in west, central, and east Africa. Countries in which they appear regularly are Sierra Leone, Kenya, Angola, Mozambique, Ghana, Liberia, Senegal, Congo, Cameroon, Gabon, the Central African Republic, and Ivory Coast.

SCALY-TAILED SQUIRRELS HABITAT

Scaly-tailed squirrels prefer the open woodlands of east, central, and west Africa and the rainforests of west and central Africa.

SCALY-TAILED SQUIRRELS DIET

Larger scaly-tailed squirrels eat bark and twigs from more than a dozen species of tree, but their favorites are miombo, velvet tamarind, ironwood, owala oil, and awoura. They occasionally also eat insects and gum (tree sap). The smaller squirrels eat almost nothing besides gum and insects.

BEHAVIOR AND REPRODUCTION

Because of the remoteness of their habitats and the animals’ secretive nature, scientists know relatively little about the anomalurids, members of the Anomaluridae family. However, it has been observed that the scaly-tailed squirrels clear out small branches that obstruct their habitual gliding paths. In doing so, along with their method of pruning the tops of non-food trees to keep them from crowding out their favorite food trees, the squirrels perform important functions in their ecosystems. They dislike coming to the ground, and when forced to do so move in a clumsy, kangaroo-like fashion to the nearest tree. Their gliding membranes fold away neatly when not in use, and do not prevent the squirrels from quickly scurrying along tree branches like their familiar garden-variety counterparts.

Anomalurids compete with hornbill birds for dens, which they typically make in old, hollowed out trees up to 131 feet (40 meters) high. They also battle eagles, which sometimes come in to snatch their young for prey. Females have litters of up to three pups, which are born with open eyes and thick fur. Their parents wean them from milk onto solid food by feeding the pups already chewed food from special cheek pouches. The squirrels communicate largely by scent, and use large glands in their groins to mark areas, but observers have heard them making a twittering noise as well. Field biologists believe that scaly-tailed squirrels may reach population densities of 500 individuals per 1.2 square miles (1 square kilometer). They often spend their days clinging to the side of a tree. The squirrels usually associate in pairs, but some species have been seen collected into large groups within a single den.

SCALY-TAILED SQUIRRELS AND PEOPLE

The mammals are sometimes accused of raiding oil palms for their nuts, but in general they have very little interaction with humans. Conservationists have worked to limit or stop the harvesting of the squirrels’ food trees, many of which are valuable sources of high-quality commercial lumber.

CONSERVATION STATUS

Despite logging of their food trees and a general decline in habitat quality and quantity, scaly-tailed squirrel species are not considered threatened.