Anomalurus derbianus
Lord Derby's scaly-tailed squirrel

Lord Derby's flying squirrel inhabits the tropical and subtropical forests of western and central Africa.

The principle habitat is heavy virgin rainforests (Grzimek, 1990) (Nowak, 1991).

Anomalurus derbianus are squirrel-like in form and have a head-body length of 27-37.9 cm. Their tail is approximately 22-28.4 centimeters in length. The upper side of the tail is bushy with a hairy tuft at the end. The fur is silvery-grey on its dorsal side, with the ends of individual hairs brushed in white. The fur on the belly is dense and completely white. These color markings blend well against the background of a tree. Lord Derby's flying squirrels have long whiskers, big pouch-like ears, and large eyes. Their digits are well developed and they have strong claws. Anomalurus derbianus possess a hairy gliding membrane that extends between the forelimbs and the hind limbs and between the hind legs and the tail. This membrane is heavily covered with hair on the top, and sparsely covered on the underside. These scaly-tailed squirrels receive their name from the presence of two rows of overlapping scales on the underside of the tail near the base (Grzimek, 1990) (Nowak, 1991) (Rosevear, 1969).

Anomalurus derbianus are mainly crespuscular and nocturnal. They sleep during the day in nests constructed in the holes of trees. These scaly-tailed squirrels can live alone or in pairs; however, several animals may inhabit the same tree. Lord Derby's flying squirrels leave their retreats soon after sunset, gliding from a high level in one tree to a lower level in another. These "flying" rodents leap into the air with their arms, legs, and tail extended, which stretches their membrane, allowing the animal to glide a surprising distance. They do not actually fly. One incredible glide of A. derbianus was seen to cover 100 meters, and another was reported to have gone 250 meters! When a Lord Derby's flying squirrel alights on a lower tree trunk, it thrusts the scales on the underside of its tail into the bark of the tree, using them as an "antiskidding" device. The scales are also used as an aid in climbing up the rough bark of trees. Anomalurus derbianus do not come to the ground voluntarily. The gliding membrane greatly restricts their terrestrial mobility, and when intentionally placed on the ground, they run away by hopping clumsily, like kangaroos. They also may become quite aggressive, defending themselves with their sharp claws and incisors. (Delany, 1975) (Grzimek, 1990) (Nowak, 1991).

Lord Derby's flying squirrels are herbivorous, eating a variety of plant products such as bark, fruit, leaves, flowers, and green nuts. Insects are sometimes included in the diet, but this is most likely by accident (Grzimek, 1990) (MacDonald, 1985).

Due to the rapid deforestation of their habitat, Lord Derby's flying squirrels are increasingly endangered. No specific protection, however, exists for this species. Any attempts to decrease habitat destruction in Africa will help protect A. derbianus (Grzimek, 1991).

The systematic position of Anomalurus derbianus has been greatly debated. They have been grouped with the porcupines, the mouse-related rodents, and the squirrel-related rodents. They are sometimes included in a separate suborder, Anomaluromorphia, and superfamily, Anomaluroida. Although these animals resemble squirrels in external appearance, parts of their internal anantomy indicate no close relationship to squirrels. The little information known about their predecessors helps to further complicate their phylogenetic classification. The longevity of Lord Derby's flying squirrels is estimated to be several years (Grzimek, 1990) (Nowak, 1991).