Bats occur on most of central Seychelles, with the exception of some of the outlying cays (Birds, Denis, Platte & Coetivy). They also occur on the atolls of the Aldabra group but are not established on the Amirantes, Farquar or Agalega.
The Sheath-tailed bat Coleura seychellensis is one of only two mammals endemic to Seychelles. It is possibly the rarest bat in the world with only about 100 individuals left in Seychelles.
It was once commonly found in Seychelles, but the species has undergone a dramatic decline in population during the mid to late 20th century. At present, it is listed as critically endangered under the IUCN Red Data globally threatened bat species of the world. The Department has ongoing monitoring programs and latest data shows an increase especially on Silhouette Island.
Very little is known about the bat’s ecology, habitat and behavior. Several possible causes for its decline have been forwarded, including predation by Barn Owls, roost disturbance, habitat loss and decline in insect availability as a result of pesticides use.
This bat feeds on insects at night time using echolocation calls to detect objects and navigate.
At present, the long-term conservation of the species is maintained through constant monitoring and reporting on status of present known roosts. It is accepted that for stable populations in stable environments, 500 individuals may be sufficient to guarantee long-term persistence of the population. More study needed.
The fruit bat of Seychelles was originally named Pteropus edwardsii (wright 1868) and renamed Pteropus seychellensis seychellensis by M. Edwards in 1887.
P. S. Seychellensis usually has a black back interspred with grey hairs, a black or brown muzzle, yellow mantle and a yellow or orange ventral surface tending to grey or black towards the legs and is widely distributed throughout the central granitic Seychelles. Roosts are found on all the large islands and temporary roosts are recorded on smaller islands. Roosts are located in tall trees such as from the coast Casuarina woodland to the higher Albizia dominated forests of the Morne Seychellois National Park. During most of the day, it sleeps hanging from one foot but are also often observed feeding and flying during daytime. Groups are frequently observed flying between islands to feed and ‘chest dip’ in sea water. As well as being a seed disperser, the Seychelles fruit bat act as a pollinator to both introduced and endemic floral species through spread of seeds from source to roots.