河马也能闻声识友

野生河马是吵闹的动物 ，叫声可以传到湖泊和河流另一边的远处 。但到目前为止
，这种动物发出的一种响亮叫声有何确切的作用仍是一个谜
。不过，科学家现在有了一个有趣的发现。, ,Hippos are noisy creatures making squeals ¹, grunts ², bellows ³ and honks ⁴. But until now, the function of the loudest ‘wheeze honks' the animals make has been a mystery.,河马是会发出尖叫声、哼哼声 、低吼声和鸣叫声的吵闹动物 。但到目前为止 ，这种动物发出的最响亮的 “喘叫声 ” 有何用处仍是一个谜
。, ,The researchers recorded hippo talk at a nature reserve in Mozambique to find out more about the behaviour of these talkative mammals. They broadcast the recordings ⁵ through loudspeakers over lakes and found resident hippos responded differently to friends, neighbours and strangers, suggesting they could tell each other apart.,研究人员在莫桑比克的一个自然保护区记录了河马之间的交流
，以了解这些叫个不停的哺乳动物的更多习性。他们用扩音器在湖边播放河马叫声的录音，发现当地河马对同伴
、邻居和陌生河马的反应不同 ，表明它们可以区分彼此 。, ,Hippos are not yet endangered, but their numbers are plummeting ⁶ fast. The scientists say their study has important implications for conservation policy and could help the management of hippo populations in the wild.,虽然河马尚未濒临灭绝，但它们的数量正在骤减。科学家表示
，他们的研究对动物保护政策有重要意义，可能有助于野生河马种群的管理
。