Good Friends, Fresh Blood: The Social Life of a Vampire Bat

Most people would not think of friendship and cooperation when considering the animals called vampire¹ bats.

But experts say maybe we should.

New research shows that vampire bats have deeper social relationships with one another than scientists had thought. The study shows that vampire bats form friendships and meet at feeding time to hunt together.

Researchers attached small devices to 50 vampire bats in Panama to follow their path as they feed at night. The bats drink blood from wounds they cause on cows in open fields. The study involved female bats, as researchers believe they have stronger social relationships than males.

Twenty-three bats born in the wild had been captured and studied for about two years for related research into bat social behavior. Social connections had already been observed among some of them. They live together in trees, clean each other and share meals.

The scientists used tiny sensor² devices on the flying mammals to learn whether their hunting behavior was also social. The sensor data showed that the bats would often join a "friend" while searching for food.

Gerald Carter is a scientist with the Ohio State University and the Smithsonian Tropical Research Institute. He led the research published in the journal PLoS Biology.

"This study opens up an exciting new window into the social lives of these animals," he said. "Each bat maintains its own network of close cooperative social bonds."

The researchers suspect that the bats join their friends during the hunt to help each other. They think the bats might exchange information about prey³ position or access to an open wound for feeding.

Vampire bats live in the warmer areas of Central and South America. They have wingspans of about 18 centimeters and are the only warm-blooded animals with a blood-only diet. They live in groups called colonies that can number from the tens to thousands of individuals.

Simon Ripperger is a researcher at the Smithsonian Tropical Research Institute and a writer of the study. He said people's first reaction to vampire bats is usually fear.

He added, "But once you tell them about their complex social lives, they are quite surprised that we can find such behavior that is somewhat similar to what humans do - and which one would maybe expect in primates⁴ - in bats."

Ripperger noted⁵ that the bats are fast runners and have heat sensors⁶ in their noses to help them target a good place to bite prey.

The bats attack from the ground, using their sharp teeth to open a wound on an animal. Then, they use their tongues to get blood from the wound.

Gerald Carter said there is reason to fear vampire bats because they can spread the deadly disease rabies to both animals and people.

"But I do think they are beautiful and interesting animals in their own right," Carter added. "In this way they are a bit like grizzly⁷ bears, sharks, rats and venomous snakes: animals that might not help people in any way and might even endanger them, but should still be appreciated for their own sake."

Words in This Story

prey – n. an animal that is hunted or killed by another animal for food

access – n. a way by which a thing or place may be approached or reached

wingspan – n. the distance from the tip of one wing of a bird or airplane to the tip of the other wing

venomous – adj. capable of putting poison or venom⁸ into another animal's body usually by biting or stinging it

appreciated – v. admired greatly

1 vampire   

n.吸血鬼

参考例句：

• It wasn't a wife waiting there for him but a blood sucking vampire!家里的不是个老婆，而是个吸人血的妖精！
• Children were afraid to go to sleep at night because of the many legends of vampire.由于听过许多有关吸血鬼的传说，孩子们晚上不敢去睡觉。

2 sensor   

n.传感器，探测设备，感觉器（官）

参考例句：

• The temperature sensor is enclosed in a protective well.温度传感器密封在保护套管中。
• He plugged the sensor into a outlet.他把传感器插进电源插座。

3 prey   

n.被掠食者，牺牲者，掠食；v.捕食，掠夺，折磨

参考例句：

• Stronger animals prey on weaker ones.弱肉强食。
• The lion was hunting for its prey.狮子在寻找猎物。

4 primates   

primate的复数

参考例句：

• Primates are alert, inquisitive animals. 灵长目动物是机灵、好奇的动物。
• Consciousness or cerebration has been said to have emerged in the evolution of higher primates. 据说意识或思考在较高级灵长类的进化中已出现。

5 noted   

adj.著名的，知名的

参考例句：

• The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
• Jim is noted for arriving late for work.吉姆上班迟到出了名。

6 sensors   

n.传感器，灵敏元件( sensor的名词复数 )

参考例句：

• There were more than 2000 sensors here. 这里装有两千多个灵敏元件。 来自《简明英汉词典》
• Significant changes have been noted where sensors were exposed to trichloride. 当传感器暴露在三氯化物中时，有很大变化。 来自辞典例句

7 grizzly   

adj.略为灰色的，呈灰色的；n.灰色大熊

参考例句：

• This grizzly liked people.这只灰熊却喜欢人。
• Grizzly bears are not generally social creatures.一般说来，灰熊不是社交型动物。

8 venom   

n.毒液，恶毒，痛恨

参考例句：

• The snake injects the venom immediately after biting its prey.毒蛇咬住猎物之后马上注入毒液。
• In fact,some components of the venom may benefit human health.事实上，毒液的某些成分可能有益于人类健康。