Passage1

Bats to the rescue

蝙蝠来拯救

How Madagascar’s bats are helping to save the rainforest

马达加斯加的蝙蝠如何助力拯救雨林

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.

世界上很少有其他地方在农业与环境保护之间存在着更紧张的关系了。马达加斯加的森林正在以每年百分之一的速率被转化成农业用地。推动这种破坏的一个主要因素是这个国家所种植的主食作物：水稻。而造成这种破坏的一个关键原因则是各类害虫正在祸害大量的当地农夫为谋生计而种植的庄稼，导致他们只能开垦森林以创造新的稻谷田地。结果就是彻底破坏了这座岛上的栖息地和造成生物多样性的损失，然而并非所有的物种都在受难。实际上，岛上有一些以昆虫为食的蝙蝠就正过得兴旺繁荣，这对于农夫和环境保护者来说都有着重要的提示。

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.

剑桥大学动物学家Ricardo Rocha挺身而出。他对于环境保护和蝙蝠都充满热情。更具体来说，他的兴趣点在于蝙蝠是如何回应人类活动，特别是森林乱砍滥伐这种活动的。罗查的新研究显示：有几个品种的蝙蝠正在为马达加斯加的稻农提供一项至关重要的害虫控制服务，因为它们大规模捕食成灾的昆虫。而这一点，他坚信，可以减轻农夫们将森林改作农田的经济压力。

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.

蝙蝠大约占到马达加斯加所有哺乳动物物种的五分之一，36个有记录的蝙蝠品种都原产于这座岛，这就使得此地成为世界上对这个动物种群进行保护的最重要地区之一。

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.

罗查率领着一支科学家国际团队，发现好几个本地蝙蝠品种正在充分利用着这种栖息地改变，猎食着盘旋在这个国家水稻田上方的大群昆虫。这些品种包括马达加斯加鼠耳蝠、马加长趾蝠、马达加斯加白腹犬吻蝠和彼氏皱唇蝠。

‘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.’“

这些赢家物种正以生物性害虫压制者的身份在为马达加斯加提供一项宝贵的免费服务。”罗查说道。“我们发现了六个品种的蝙蝠在捕食稻田害虫，其中包括灰翅夜蛾和水稻切叶野螟。这些昆虫所造成的破坏使得岛上农夫们承受了巨大的经济压力，而这又促进了伐林造田的行为。”

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.

这项研究，目前发表在期刊《农业、生态系统与环境》上，着手调研了以昆虫为食的蝙蝠在该国东南部拉努马法纳国家公园边界处的农田里的捕食活动。

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.

罗查及其团队使用最新的超声波录音设备记录下了来自54个不同地点、超过一千种蝙蝠的“进食嗡鸣”（蝙蝠用来定位猎物时所使用的回声定位音序），以此来确认蝙蝠最喜爱的猎食地点。他们接下来使用了DNA条码技术来分析在不同地点收集的蝙蝠粪便。

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).

这些记录显示，蝙蝠在稻田上空的活动量远比在绵延的森林中要高得多——在位于平地的稻田上方的活动高出了七倍，在位于山坡的稻田上方则多出了十六倍——毫无疑问地表明：这种动物更偏爱在这些人工生态系统中觅食。研究者们认为，蝙蝠偏爱这些区域是因为缺水和营养流失使得这些庄稼更容易受到虫害的侵扰。DNA分析显示，所有六个品种的蝙蝠都捕食了会对经济产生举足轻重影响的害虫。虽然这些研究结果表明水稻种植最为受益于这些蝙蝠，但科学家们还发现了一些迹象足以证明这些蝙蝠也捕食侵扰其他作物的害虫，其中包括黑色枝小蠹（侵害咖啡作物）、甘蔗蝉、坚果异胫小卷蛾，以及平纹鳞翅蛾（一种侵害柑橘类水果的害虫）。

'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.’“

蝙蝠作为害虫控制者的有效性在美国和加泰罗尼亚已经得到了证实。”来自里斯本大学的合著作者James Kemp这样说。“但我们的研究第一次证明了这种情况也发生在马达加斯加，在这里，农夫和环境保护者都面临着极大的损失代价。”

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.

本地人也许还有另一个理由要感谢他们的蝙蝠。虽然这种动物经常与传播疾病联系在一起，但罗查及其团队发现有证据表明马达加斯加蝙蝠捕食的不仅是庄稼害虫，而且还有蚊子——携带疟疾、裂谷热病毒和象皮病等病原——以及散播河盲症的黑蝇。

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.’

罗查指出，这是一种很复杂的关系。当食物短缺时，蝙蝠就成为当地人的一种重要的蛋白质来源。就连儿童也会去捕食它们。除了栖息在树间，蝙蝠有时候也会栖息在建筑里，但在那些地方并不受欢迎，因为它们会弄脏环境。然而，与此同时，它们又与神圣的洞穴和祖先联系在一起，因此可以被视作穿梭往来于不同世界之间的生灵，这使得它们在当地人的文化中十分重要。还有一个潜在问题：虽然这些蝙蝠正在受益于农业生产，但与此同时森林的乱砍滥伐也正在减少它们可以栖身的地点，这从长远来讲也许会影响到它们的数量。罗查指出：“通过给出恰当的帮助．我们希望农夫们可以通过建造蝙蝠屋来提升这种彼此受益的关系。”

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.’

罗查及其同事们都相信：将蝙蝠种群数量最大化可以有助于提升庄稼产量并促进人们的可持续发展生计。这支团队目前正在呼吁展开进一步的研究来量化这种贡献的程度。“我感到非常乐观。”罗查这样说道。“如果我们给大自然帮把手，我们就能加速这个复兴的进程。”