By Zachary Fagenson

MIAMI (Reuters) - Shortly after dusk, three researchers squat on the lawn of a vacant, million-dollar home in a posh Miami suburb, pointing ultrasonic microphones at the darkened mansion.

They're part of the Miami Bat Squad, listening to track down the home of the rare Florida bonneted bat - a critically endangered species that has turned up at a nearby golf course.

Scientists know little about the brown, snout-nosed creature, which emits unusual audible noises as it flies and whose population is believed to number only a few hundred. The bonneted bats exist only in southern Florida.

But last week, the Miami Bat Squad announced that it had located what is believed to be the first known roost of the rare creature in decades.

The group, made up of about 200 volunteers, has been trying to find the daytime home of the species since they were heard circling a golf course in the upscale community of Coral Gables earlier this year.

“I was on the back porch drinking a glass of wine and thought ‘Oh my God, those are bats,'” said Florida International University biologist Kirsten Bohn, who recognized their faint chirping after she moved into the area recently.

Bohn has been leading efforts to locate precisely where the bats roost by day, count their numbers and gather any other information that could help preserve them. They were added to the U.S. endangered species list last fall.

“This one is a special case, because so little is really known about its habits,” said Ken Warren, a spokesman for the U.S. Fish and Wildlife Service.

For the past several weeks, volunteers have walked the golf course at dusk, watched trees and rooftops and listened for bat cries. To rally the bat seekers, Miami-based spirits maker Bacardi Ltd, whose bat logo pays homage to roosts in its Cuban distillery during the late 19th century, supplied free drinks for one of the volunteer events.

Last week, the group narrowed down the roost to the posh house with the red Spanish tile roof at the edge of the golf course. Now they are working to find the precise location, and to try to ascertain the number of bats in the colony.

On one recent evening, researchers tucked high frequency recorders around the house. As Bohn listened for bat sounds measured by computer software, a shadowy silhouette emerged from a crack in the roof, then zipped overhead with a fast-pitched series of metallic chirrups.

Bohn was ecstatic, and hopes to prove that the bat, which is thought to live in groups of less than a dozen, may have been calling to friends.

She and her graduate students debated whether to scale the house to collect bat droppings to ship to a London-based analyst aiding their effort, but decided to wait until morning.

“We know where they are now,” she said.


(Editing by Letitia Stein, David Adams and Eric Walsh)