READING PASSAGE 1

You should spend about 20 minutes on Questions 1–13, which are based on Reading Passage 1 below.

Bats to the rescue

How Madagascar’s bats are helping to save the rainforest

There are few places in the world where relations between agriculture and conservation are more strained. Madagascar’s forests are being converted to agricultural land at a rate of one percent

every year. Much of this destruction is fuelled by the cultivation of the country’s main staple crop: rice. And a key reason for this destruction is that insect pests are destroying vast quantities of what is grown by local subsistence farmers, leading them to clear forest to create new paddy fields. The result is devastating habitat and biodiversity loss on the island, but not all species are suffering. In fact, some of the island’s insectivorous bats are currently thriving and this has important implications for farmers and conservationists alike.

Enter University of Cambridge zoologist Ricardo Rocha. He’s passionate about conservation, and bats. More specifically, he’s interested in how bats are responding to human activity and deforestation in particular. Rocha’s new study shows that several species of bats are giving Madagascar’s rice farmers a vital pest control service by feasting on plagues of insects. And this,

he believes, can ease the financial pressure on farmers to turn forest into fields.

Bats comprise roughly one-fifth of all mammal species in Madagascar and thirty-six recorded bat species are native to the island, making it one of the most important regions for conservation of this animal group anywhere in the world.

Co-leading an international team of scientists, Rocha found that several species of indigenous bats are taking advantage of habitat modification to hunt insects swarming above the country’s

rice fields. They include the Malagasy mouse-eared bat, Major’s long-fingered bat, the Malagasy white-bellied free-tailed bat and Peters’ wrinkle-lipped bat.

‘These winner species are providing a valuable free service to Madagascar as biological pest suppressors,’ says Rocha. ‘We found that six species of bat are preying on rice pests, including the

paddy swarming caterpillar and grass webworm. The damage which these insects cause puts the island’s farmers under huge financial pressure and that encourages deforestation.’

The study, now published in the journal Agriculture, Ecosystems and Environment, set out to investigate the feeding activity of insectivorous bats in the farmland bordering the Ranomafana National Park in the southeast of the country.

Rocha and his team used state-of-the-art ultrasonic recorders to record over a thousand bat ‘feeding buzzes’ (echolocation sequences used by bats to target their prey) at 54 sites, in order

to identify the favourite feeding spots of the bats. They next used DNA barcoding techniques to analyse droppings collected from bats at the different sites.

The recordings revealed that bat activity over rice fields was much higher than it was in continuous forest – seven times higher over rice fields which were on flat ground, and sixteen

times higher over fields on the sides of hills – leaving no doubt that the animals are preferentially foraging in these man-made ecosystems. The researchers suggest that the bats favour these fields

because lack of water and nutrient run-off make these crops more susceptible to insect pest infestations. DNA analysis showed that all six species of bat had fed on economically important insect pests. While the findings indicated that rice farming benefits most from the bats, the scientists also found indications that the bats were consuming pests of other crops, including the

black twig borer (which infests coffee plants), the sugarcane cicada, the macadamia nut-borer, and the sober tabby (a pest of citrus fruits).

‘The effectiveness of bats as pest controllers has already been proven in the USA and Catalonia,’ said co-author James Kemp, from the University of Lisbon. ‘But our study is the first to show this

happening in Madagascar, where the stakes for both farmers and conservationists are so high.’

Local people may have a further reason to be grateful to their bats. While the animal is often associated with spreading disease, Rocha and his team found evidence that Malagasy bats feed

not just on crop pests but also on mosquitoes – carriers of malaria, Rift Valley fever virus and elephantiasis – as well as blackflies, which spread river blindness.