IELTS Reading Exercise 4

In Awe Of Bats

A.

Recently, conservationists in the UK developed a revolutionary wind tunnel designed to save the lives of injured bats. An extractor fan recreates their flying conditions and they regain their strength before being released back into the wild. In Brazil, biologist Rebecca Shapley uses high-tech computer technology and nets to capture and identify bat species in the vast Jau National Park. In Science View, she explains why scientists are in awe of bats and why conservation of these tiny mammals is essential. Bats comprise about one-fifth of all mammals. They come second to rodents in terms of population figures. But because they are active at night scientists find it difficult to work with them. Consequently, many species have never been studied and are excluded from surveys. At Jau National Park, in the north of Amazonas state, biologist Rebecca Shapley's mission is to record the indigenous bat species. Through her research, she aims to create a comprehensive list as there is none to start with. Because bats comprise over half of all mammal species in tropical ecosystems, Shapley believes studying them is crucial to any conservation effort. She says: "You can't really have a realistic understanding of a national park's management plan, or make an impact, if you don't have an understanding of bats...making a list of the bats in Jau National Park is a good beginning."

B.

Different bat species play important roles in the ecological system they belong to. Importantly, they control the insect population. According to an Online report by the US Fish and Wildlife Service: "One bat can eat between 600 and 1,000 mosquitoes and other insect pests in just one hour." Bats are also important seed dispersers. Some species disperse thousands of seeds in one night. When in flight, bats tend to drop seeds, often at great distances from the point of collection. In addition, their droppings or guano, an important fertiliser for crops, contain a large number of seeds, which are deposited during their travels. Fertilisation is yet another of their vital roles. They pollinate plants that can only be pollinated by them, such as The Saguaro Cactus. The Saguaro can live for several centuries but it only blossoms when it reaches 50 to 60 years of age. It opens its white flowers at night and closes them with the arrival of daylight. Long-nosed bats probe the blossoms in search of nectar. They then scatter the pollen adhered to their fur to hundreds of other flowers. Bats also pollinate thousands of tropical and subtropical trees. They help produce the peaches, bananas, mangoes and avocados human beings love to eat.

C.

In order to capture them, biologists tend to use two methods: a mist net and a harp net. Mist nets are fine vertical meshes, which are placed in the passages of forests. A harp net is a series of vertical strings with a sack at the bottom. It covers the entrance to the roost. Bats try to fly between the strings. Because they have no room to beat their wings, they fall down into the pouch. To make her list of bat species, Shapley uses 3 to 12 metre tall mist nets. When bats forage, capture tends to be successful. But some bats avoid this device through echo-location - by sending out a high-frequency call which bounces back offering a three-dimensional image of their pathway. For these clever bats, a harp trap is required. Shapley explains: "It's very much like a harp, except it's square and not very musical. Bats see it, but think they can get out of it. In the middle of it they realise they can't. They fall down into a little sack, which gives them some protection. They roost there until you come and identify them." Until recently, biologists considered some species to be extremely rare but new studies suggest perhaps some species are simply more cunning than rare.

D.

There is one research tool that has little to do with traditional nets used by scientists. It's the Anabat electronic computer used to record bat echolocation calls. In layman's terms, the system takes a voice print of the bat as it flies past. It records calls and stores them as computer files. Shapley explains: "I can sit in this research station, and use this to record the bats that are echolocating around me. We still have to catch the bat. Just having the call is not enough. You have to know whose making that call." After recording the voice prints, Shapley matches the call with the recorded sounds of other species stored in the Anabat's archive and in bat research libraries.

E.

So far, Shapley has identified 28 species and more are sure to pop up. One is the fruit-eating Carollia perspicillata, which shuffles between trees in the forest to roost. She has also caught a family of three very rare fish-eating bats, adding their sound to the Anabat's archive.

Source: bbc.co.uk