In 2008 FIJI Water committed $5 million to preserve 50,000 acres in the Sovi Basin, one of the largest remaining lowland rain forest in the South Pacific, and an important part of the Polynesia/Micronesia biodiversity “hotspot.” As part of a continuing series, we will be profiling some of the rare and endangered creatures found there.

The Sheath Tail Bat: Barely Hanging On

It would be hard to find a better argument for preserving the Sovi Basin rain forest than the sheath tail bat. Once relatively common in many of the islands of the South Pacific, sheath tail populations have been mysteriously dropping since at least Word War II.

Known locally as Bekabeka and by science as Emballonura semicaudata, the sheath tail, like many other bats, eats insects, hunts at night (is nocturnal), and roosts in caves. Sunset at a sheath tail roosting cave is an awesome event as bats swarm out of their cave by the hundreds in search of breakfast, lunch, and dinner.

Like other bats, Bekabeka also hunts using echo-location. These bats can determine the size and nature of objects in front of them just by analyzing the sonar echoes they receive from the objects.

A Mysterious Drop in Bat Populations

Because the sheath tail has been little-studied, scientists aren’t exactly sure why populations are dropping. Bombing of island caves during World War II, feral cats, eco-tourism, forest loss, and insecticides have all been blamed for steady declines in populations throughout the South Pacific. As a result of these declines, the bat is on the IUCN’s Endangered Species Redlist, and many Pacific governments have passed laws to protect them.

Fiji is one of the few places with a steady population of sheath tails. In 1979, the last sheath tail was observed on Fiji’s main island of Viti Levu, but bat populations still exist on smaller islands scattered around the archipelago.

The disappearance of the sheath tail, besides being a loss to biodiversity, would have further repercussions: Where they still exist, sheath tails play an important part in maintaining the population of flying insects.