Gambian Epauletted Fruit Bat - Reproduction

Reproduction

The Gambian Epauletted Fruit bats show sexual dimorphism. The males of these species are usually larger than the females and in addition possess glandular pouches in the skin of the shoulder which are surrounded by light colored tufts of hair. These produce the effect of epaulets, and are how the species received its name (Wilson).

The species have more than one mate at a time. The males emit mating calls during the breeding season; which is around April to May and October to November (Wimsatt).

Males fly at night to different locations to mate. There, they begin courting calls which attracts the females. While making their mating calls, males will flash snowy white patches of fur on their shoulders, called epaulets, which are usually concealed. Because they do this at night, the large white furs are more visible under the lighting conditions (Wilson).

The gestation period usually lasts about six months, and pregnant females will roost apart from the males. There is usually one young per birth (Morris).

Although fertilization ensues immediately after mating, there is little development of the embryo. The delay in embryonic development ensures that birth coincides with a season when food is abundant enough to maintain lactating females, which have a high demand for energy. The delay in embryonic development also permits mating to take place when both males and females are in prime physical condition and have access to good supplies of food (Wimsatt).

Newborns grow rapidly, with various parts of their bodies growing at different rates. At birth, the thumbs and hind feet are almost adult size, and grow very little. However, the forearm and other bones supporting the wing enlarge quickly, producing a wing area in adults that is 10 times the size at birth. They rapidly gain weight until they are weaned. But once they begin to eat fruit instead of their mother's milk, their body weight decrease and they use up the fat reserve they have built up during nursing (Wimsatt).

At birth the species are equipped with distinctive milk teeth that appear to be useless as tools for eating solid food, but help them attach to their mother's teats. The shedding of milk teeth and the emergence of permanent teeth occurs at about the same time as the bats learn to fly and begin to eat fruit (Fenton).

The lifespan of this bat is long for being such a small mammal. Most epauletted fruit bats can live up to 28 years, and average about 21 years. The mechanism for such long life in bats is not know with certainty. Some suggest the longevity in bats is related to the calpain content of neurons (Fenton).