The Rodrigues Fruit Bat
[ Pteropus rodricensis ]
Of the approximate 1,100 species of bat that live worldwide, the Rodrigues fruit bat was until recently one of the most endangered.
In its native habitat on the tiny western Indian Ocean island of Rodrigues, one of the Mascarine island group, off the coast of Madagascar, precious little forest remains.
All bats are nocturnal – they rest during the day and leave their roosts at dusk to feed during the night. Old World fruit bats navigate and locate food using their well-developed eyesight and sense of smell.
The fruit bat digestive system is specialised for a mainly liquid diet and a rapid gut passage rate – fruits, flowers and leaves are chewed to extract all the juice and the remaining fibrous portion is spat out as a pellet. Rodrigues fruit bats eat the leaves, fruits or flowers of manydifferent species of plant, but more research on their diet in the wild is needed.
Pteropus fruit bats usually live in large colonies or ‘camps’ with a social structure based on dominance. Dominant males and their ‘harem’ ofup to 8 breeding females are in the centre of the colony in the best, most protected territories and on the outskirts are subordinate males and juveniles. In the wild, fruit bats are seasonal breeders and in the tropics, young tend to be born at the start of the rainy season when food is plentiful – usually August to October in Rodrigues.
The World Conservation Union (IUCN) currently classifies Rodrigues fruit bat as Critically Endangered on the Red Data List (2000), on the advice of the IUCN’s bat specialist group. This means that it faces an extremely high risk of extinction in the wild in the immediate future.
This makes the bats increasingly vulnerable to cyclones, which frequently strike in the region. Surveys back in the mid-1970s found the population to be very small – just 130 or so individuals.
Captive breeding programmes alone are never enough to prevent extinction, but must be coupled with efforts to protect and restore species’ natural habitat as well as education programmes for the local population. Thanks, in part, to the conservation work of Durrell alongside that of local agencies, each of these measures are in place to assist in the protection of the Rodrigues’ habitat, and as a result the wild bats continue to make a steady comeback, although they are still Critically Endangered. Durrell’s success with Rodrigues fruit bats has helped to establish a similar programme for the larger Livingstone’s fruit bat from the Comoros islands, also in the western Indian Ocean. The population on Rodrigues is now estimated to be 3000 and rising.
The situation certainly seems to be improving for the bats, as their population is increasing steadily, however ongoing conservation work and monitoring of the bat population by local agencies is critical to ensuring the population of wild bats continues to flourish.
Thanks to the effective combination of captive breeding [at places like The Durrell Trust / Jersey Zoo], research, education, and habitat protection and restoration, the future of the Rodrigues fruit bat is now not as bleak as it would have been without these conservation measures.
[Information referenced from the Durrell Trust web site].