Saving Paradise

Category: Bats | Date: Jul 20 2009 | By: savingparadise

On July 15, 2009 I accompanied Terence for a monitoring exercise for the Seychelles Sheath-tailed bat Coleura seychellensis carried out by Nature Seychelles at Baie Lazare, Mahe.

Baie Lazare has one of three roosts on Mahe occupied by the endemic and very rare Seychelles Sheath-tailed Bat. So rare is the bat and so limited its range that it has been listed as Critically Endangered on the IUCN Red List, and is considered close to extinction. The bat is also listed by EDGE (the edge of existence programme), the global conservation initiative which focuses on threatened and unique species.

The Seychelles Sheath-tailed bat was once abundant on Praslin, La Digue, Mahé and Silhouette. It suffered a dramatic decline during the mid-late 20th Century. The exact cause of the population decline is unknown, but it’s been linked to habitat destruction, human disturbance, decline in insect density, and possible predation by barn owls. Recent studies failed to detect any bats at previously known roosting sites on the islands of La Digue and Praslin, and the species is now thought to be extinct on both islands. This bat is now only known to roost on Mahe and Silhouette, with an estimated 50-100 individuals believed to exist. Past records show 32 individuals at La Passe on Silhouette, and 36 individuals at three roosts on Mahé: Cap Ternay, Baie Lazare, and Anse Major.

The monitoring is being done with the help of two volunteers and on this day we were accompanied by Ian Valmont.  Ian and the others have been recording dusk emergence of individuals at the roosts on Mahe. We sit outside the roost where we can see bats emerge. Ian and Terence are carrying ultrasonic detectors (Bat box) set to 37 kHz to detect when a bat is approaching. However, the counts are based on actual visuals of the bats. At this roost, 7 individuals have been recorded and all were seen on this day. Other observations on  the bats behavior and the status of the habitat are also recorded.

The bats are difficult to photograph at emergence as they fly past rather fast. My amateur skills produced very poor quality video from our digital camera. I am hoping that at the next monitoring I will be more successful. However we did manage to record some audio files on Terence’s phone picked up by the “Bat box” as they emerged (Terence is photographed here climbing to the cave with Ian Valmont, carrying the bat detector). I have uploaded it here for your listening pleasure.

Very little is known of the bat’s status and ecology, so this monitoring, part of a project that started in 2006, helps to contribute to existing data and  identify threats to its continued existence. The threat to the bats is real and present due to its unprotected status and the fact that it relies on coastal habitats which have come under intense pressure from housing and tourism development on both Mahé and Silhouette.

Find more information on the bat at EDGE

Tags: Seychelles Sheath-tailed Bat

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