第1段

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.

第2段

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.

第3段

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.

第4段

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.

第5段

‘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.’

第6段

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

第7段

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.

第8段

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).

第9段

‘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.’

第10段

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.

第11段

Rocha points out that the relationship is complicated. When food is scarce, bats become a crucial source of protein for local people. Even the children will hunt them. And as well as roosting in trees, the bats sometimes roost in buildings, but are not welcomed there because they make them unclean. At the same time, however, they are associated with sacred caves and the ancestors, so they can be viewed as beings between worlds, which makes them very significant in the culture of the people. And one potential problem is that while these bats are benefiting from farming, at the same time deforestation is reducing the places where they can roost, which could have long-term effects on their numbers. Rocha says, ‘With the right help, we hope that farmers can promote this mutually beneficial relationship by installing bat houses.’

第12段

Rocha and his colleagues believe that maximising bat populations can help to boost crop yields and promote sustainable livelihoods. The team is now calling for further research to quantify this contribution. ‘I’m very optimistic,’ says Rocha. ‘If we give nature a hand, we can speed up the process of regeneration.’

世界上很少有地方的农业和保护关系如此紧张。马达加斯加的森林每年以1%的速度转变为农业用地。这种破坏的很大一部分是由于种植该国主要的主粮作物——水稻。而这种破坏的一个关键原因是昆虫害虫破坏了当地自给自足农民种植的大量农作物，导致他们清理森林建立新的稻田。结果是岛上栖息地和生物多样性的巨大损失，但并非所有物种都在受到影响。事实上，岛上一些以昆虫为食的蝙蝠目前正在蓬勃发展，这对农民和保护人士都具有重要意义。

剑桥大学动物学家里卡多·罗夏进入了这个领域。他热衷于保护和蝙蝠。更具体地说，他对蝙蝠如何应对人类活动和森林砍伐特别感兴趣。罗夏的新研究表明，马达加斯加的几种蝙蝠物种通过捕食大量昆虫灾害为稻农提供了重要的害虫控制服务。他认为，这可以减轻农民们将森林转为农田的经济压力。

蝙蝠约占马达加斯加所有哺乳动物物种的五分之一，岛上有三十六种蝙蝠物种，使其成为全球蝙蝠保护最重要的地区之一。

罗夏带领一个国际科学家团队发现，几种土著蝙蝠物种正在利栖息地改变来捕食盘旋在该国田上方的昆虫。其中包括马达加斯加鼠耳蝠、马约尔长指蝠、马达加斯加白腹蝙蝠和彼得褶唇蝠。

罗夏说：“这些优势物种为马达加斯加提供了宝贵的生物害虫抑制服务。我们发现有六种蝙蝠物种以稻田害虫为食，包括稻田蚕飞虫和草飞虫。这些昆虫造成的破坏给岛上的农民带来巨大的经济压力，这促使了森林砍伐。”

这项研究现已发表在期刊上，旨在调查东南部拉诺马法纳国家公园周边农田中食虫蝙蝠的进食活动。

罗夏和他的团队使用先进的超声波记录仪在54个地点记录了一千多次蝙蝠“进食嗡嗡声”（蝙蝠用来定位猎物的回声定位序列），以确定蝙蝠的首选进食地点。然后，他们使用DNA条形码技术分析了在不同地点收集到的蝙蝠粪便。

记录显示，蝙蝠在稻田上的活动要比连续的森林要高得多——平地上的稻田要高出七倍，山腰上的稻田要高出十六倍——毫无疑问，这些动物更倾向于在这些人工生态系统中觅食。研究人员认为，蝙蝠喜欢这些田地是因为缺水和营养流失使这些作物更容易受到昆虫害虫的侵袭。DNA分析显示，所有六种蝙蝠都以经济重要的害虫为食。尽管研究结果表明稻农最受蝙蝠的益处，但科学家们还发现蝙蝠也在消灭其他作物的害虫，包括侵害咖啡植物的黑枝小蠹、甘蔗蝉、夏威夷坚果蛀螟和柑橘水疮病的害虫。

来自里斯本大学的合著者詹姆斯·坎普表示：“蝙蝠作为害虫控制者的有效性已经在美国和加泰罗尼亚得到证明。但我们的研究是首次在马达加斯加展示这一现象，这对农民和保护人士来说都非常重要。”

当地人可能还有更多理由感谢他们的蝙蝠。虽然这种动物常常与传播疾病联系在一起，但罗夏和他的团队发现马达加斯加蝙蝠不仅以农作物害虫为食，还以蚊子为食——蚊子是疟疾、裂谷热病毒和象皮病的传播者——以及传播河盲症的黑蝇。

罗夏指出，这种关系是复杂的。当食物稀缺时，蝙蝠成为当地人重要的蛋白质来源。甚至连孩子们也会捕捉它们。蝙蝠除了栖息在树上，有时也栖息在建筑物中，但人们不欢迎它们，因为它们会弄脏建筑物。然而，它们也与神圣的洞穴和祖先有关，所以它们可以被视为处于世界之间的存在，在人们的文化中具有重要意义。一个潜在的问题是，尽管这些蝙蝠从农业中受益，但同时森林砍伐也减少了它们栖息的地方，这可能对它们的数量产生长期影响。罗夏说：“在得到适当的帮助下，我们希望农民能通过安装蝙蝠屋来促进这种互惠关系。”

罗夏和他的同事们认为，增加蝙蝠数量可以提高农作物产量并促进可持续生计。该团队现在呼吁进行进一步研究以量化这种贡献。罗夏说：“我非常乐观。如果我们帮助自然一把，我们可以加快恢复的过程。”