VOA标准英语2011--Bat Populations Still in Decline

Bat Populations Still in Decline

Bats are an amazingly diverse group of flying mammals that can be found in virtually every corner of the world. Because they're mostly nocturnal and a few types feed on animal blood, bats have acquired a rather dark reputation, linked in legends to witchcraft 1 and the occult.

But most bats are harmless fruit or insect-eaters, and in North America alone, they save the farm economy billions of dollars annually 2 by controlling destructive pests and pollinating crops.

Still, bat populations have been declining rapidly for years, due to rampant 3 disease and human encroachment 4 on their habitats. Our reporter introduces us to one woman in the Washington area who is working to improve public understanding of bats, and doing what she can to help them survive.

As sunlight fades from the evening sky, Leslie Sturges checks on a colony of bats she has been monitoring.

The bats gather at the portals of their summer homes - these wooden bat boxes hung on a pole in a suburban 5 park.

One by one, the small brown bats take flight into darkness, hunting for insects and small bugs 6.

But Sturges says she's concerned that her count reveals only half the number of bats as last year. She hopes some have made an early return to the cave where they hibernate 7 in winter.

“You know my hope is that a lot of the colony already moved out," said Sturges. "But I can’t be that optimistic as far as bats are concerned in the Mid-Atlantic."

Sturges is director of a conservation group called Bat World NOVA. She cares for injured and orphaned 8 bats here in her basement. Then she releases them back to the wild.

Bat populations are declining worldwide, mostly because of habitat destruction and overuse of pesticides 9. Sturges says common fears that bats will fly into your hair, or that all bats carry the deadly rabies virus also contribute to human intolerance of bat populations.

“A lot of people refer to bats as filthy," she said. "But they aren’t. They groom 10 like cats and dogs do. They use these toes back here to actually comb their fur out.”

Sturges also teaches the importance of bats at nature centers and in schools. Her goal is to promote their protection and conservation by stressing the positive things bats contribute to the environment.

“One of the things they contribute, well around here in North America, is pest control for plant-eating insects," said Sturges. "So anyone who grows anything is getting an assist from bats.”

Contrary to popular belief, bats are not blind. Their eyesight is actually pretty good. But at night they navigate 11 in flight using a system called echo-location . They use their sensitive ears to listen for objects and bugs - that reflect back their high-pitched chirps 12 - which we can hear with this device.

“That’s his echo-location call coming through"

Sturges and her assistant, Sherry Keen, are caring for about thirty orphaned, injured, and sick bats this summer.

And these are all this year’s orphans 13.

When they start to feel well enough to fly, she moves them to this screened pen in her backyard so they can develop their flight skills.

She plans to release "Shaggy", a red bat, tonight.

“He came in as an older juvenile," she said. "And he has just been able to exhibit really good flight skills and…”

Sturges wants to make sure he has a good meal before his release.

Later, as the sun sets, it's time for the bat to return to the wild.

“Bye, Shags, be good out there," said Sturges.

But “Shags” doesn’t want to leave. He would rather sleep after a big meal.

“So I think what I am going to do is put him back in and let him nap for an hour and I am going to try and release him later on tonight" said Sturges. "Because he has to go. He can’t live here.”

Sturges says "Shaggy's" chances of survival are good. Red bats are common in the area. One last bat nap in captivity 14 and then it’s off again into the wild.