Conservationists have been astonished to find a bat in West Sussex thought to have died out in the UK.
The greater mouse-eared was declared extinct in the UK in 1992, but members of the Sussex Bat Group say that during their annual monitoring survey, a single bat was found hibernating in a disused railway tunnel.
Posting on their Facebook site, the group said that back in 2002 a single male was found in the network of tunnels, but there was no evidence of further colonisation.
A spokesman said: "This is a hugely important discovery for the us and demonstrates the importance of regular monitoring of bat colonies - we could have missed this highly significant find of the second greater mouse-eared bat in Britain.
"It also shows how important it is to safeguard these hibernation sites for bats
Dr Stephanie Murphy, of the Sussex Bat Group, said: "There are now many questions for us to answer. Is there already a small pioneer population of greater mouse-eared bats recolonising Sussex and we just don't know where they are breeding?
"Or as result of climate change and the hottest summers on record in the UK, are we getting greater mouse-eared bats just beginning to move over from mainland Europe to settle in the UK?"