ONE of the rarest bats in Britain is under threat because of a "dramatic decline" in areas where they hunt for food, experts have warned.

There are only 1000 grey long-eared bats left in the UK and numbers are declining, the Bat Conservation Trust said.

Researcher Dr Orly Razgour said the future survival of the species in the UK was questionable and called for greater efforts to protect the mammal.

She said the decline in the population of the long-eared bat is likely to have occurred as a result of a reduction in the bats' main foraging habitats - lowland meadows and marshlands.

Dr Razgour said the bats should be added to the "UK Priority Species" list of the most threatened species that require conservation action.

More work needs to be done to protect maternity roost sites, where female bats raise their young, and hibernation places, she said.

Dr Razgour said: "Despite being one the rarest UK mammals, up until recently there was very little known about the grey long-eared bat and what it needs to survive.

"It demonstrates many of the threats and conservation challenges facing wildlife, from the effects of habitat loss and climate change to the problem of small isolated populations.

"The UK grey long-eared bat population has been declining and has become fragmented in the past century. This decline and fragmentation is likely to be in response to the dramatic decline of lowland meadows and marshlands, the bat's main foraging habitats.

"The long-term survival of the grey long-eared bat UK population is closely linked to the conservation of these lowland meadows and marshland habitats."

She said that these habitats have "all but disappeared in the UK" following changes to land management and farming practices.

Grey long-eared bats live in the south coast of England, including the Isle of Wight, with a small number found in the Channel Islands. Experts have also found one of the mammals in South Wales.

They are traditionally a cave-dwelling species but have become dependent on buildings such as lofts or barns for roost sites.