[ti:Good Friends, Fresh Blood: The Social Life of a Vampire Bat]
[by:www.21voa.com]
[00:00.00]更多听力请访问21VOA.COM
[00:00.04]Most people would not think of friendship and cooperation
[00:04.24]when considering the animals called vampire bats.
[00:09.04]But experts say maybe we should.
[00:12.72]New research shows that vampire bats
[00:16.60]have deeper social relationships with one another
[00:20.12]than scientists had thought.
[00:23.60]The study shows that vampire bats form friendships
[00:28.04]and meet at feeding time to hunt together.
[00:33.12]Researchers attached small devices to 50 vampire bats in Panama
[00:39.64]to follow their path as they feed at night.
[00:44.48]The bats drink blood from wounds they cause on cows in open fields.
[00:52.24]The study involved female bats, as researchers believe
[00:57.16]they have stronger social relationships than males.
[01:02.88]Twenty-three bats born in the wild
[01:05.56]had been captured and studied for about two years
[01:09.72]for related research into bat social behavior.
[01:15.12]Social connections had already been observed among some of them.
[01:21.12]They live together in trees, clean each other and share meals.
[01:28.12]The scientists used tiny sensor devices on the flying mammals
[01:33.32]to learn whether their hunting behavior was also social.
[01:38.84]The sensor data showed that the bats
[01:41.36]would often join a "friend" while searching for food.
[01:46.88]Gerald Carter is a scientist with the Ohio State University
[01:51.48]and the Smithsonian Tropical Research Institute.
[01:56.04]He led the research published in the journal PLoS Biology.
[02:01.72]"This study opens up an exciting new window
[02:05.40]into the social lives of these animals," he said.
[02:10.32]"Each bat maintains its own network
[02:13.60]of close cooperative social bonds."
[02:18.44]The researchers suspect that the bats
[02:21.24]join their friends during the hunt to help each other.
[02:25.88]They think the bats might exchange information
[02:29.24]about prey position or access to an open wound for feeding.
[02:35.72]Vampire bats live in the warmer areas
[02:39.24]of Central and South America.
[02:42.88]They have wingspans of about 18 centimeters
[02:47.08]and are the only warm-blooded animals with a blood-only diet.
[02:53.28]They live in groups called colonies
[02:55.96]that can number from the tens to thousands of individuals.
[03:02.12]Simon Ripperger is a researcher
[03:04.56]at the Smithsonian Tropical Research Institute
[03:07.80]and a writer of the study.
[03:10.88]He said people's first reaction to vampire bats is usually fear.
[03:17.96]He added, "But once you tell them about their complex social lives,
[03:23.12]they are quite surprised that we can find such behavior
[03:26.84]that is somewhat similar to what humans do
[03:29.92]- and which one would maybe expect in primates - in bats."
[03:35.36]Ripperger noted that the bats are fast runners
[03:39.16]and have heat sensors in their noses
[03:41.92]to help them target a good place to bite prey.
[03:47.32]The bats attack from the ground,
[03:49.76]using their sharp teeth to open a wound on an animal.
[03:54.88]Then, they use their tongues to get blood from the wound.
[04:00.80]Gerald Carter said there is reason to fear vampire bats
[04:05.04]because they can spread the deadly disease rabies
[04:09.00]to both animals and people.
[04:12.76]"But I do think they are beautiful and interesting animals
[04:16.56]in their own right," Carter added.
[04:19.16]"In this way they are a bit like grizzly bears,
[04:23.40]sharks, rats and venomous snakes:
[04:27.72]animals that might not help people in any way
[04:31.32]and might even endanger them,
[04:33.72]but should still be appreciated for their own sake."
[04:38.72]I'm Jonathan Evans. 更多听力请访问21VOA.COM