Voles' last stand

日期:2019-03-07 09:02:04 作者:黄悦 阅读:

By Oliver Tickell BRITAIN’s endangered water vole, already wiped out across most of its range by North American mink, is fighting a losing battle with the brown rat in its few remaining strongholds. Rats eat both young and adult water voles, and take over their territories, the latest research reveals. “We have found water vole burrows dug up by rats to eat the young, and we have seen water vole corpses showing signs of rat predation,” says Rob Strachan of Oxford University’s zoology department. “Rats will also overpower adult water voles and kill them. We have recorded many instances of water vole decline or extinction following the arrival of rats in an area.” Strachan’s radio tracking experiments have also shown that, after rats colonise an area, water voles alter their behaviour to avoid rats. Water voles are normally active day and night on a 4-hour cycle. But after the arrival of rats, which are mainly nocturnal, the voles hardly go out at night and only go foraging during the day, limiting their ability to gather food. Water voles in lowland Britain are now largely confined to rivers, suburban areas and canals,