Some UK wildlife species will have to find new habitats as climate change causes temperatures to rise, the Wildlife Trusts have warned.
Hazel dormouse are amongst the threatened species
Animals, birds and plants will have to move north and westwards to find suitable habitats, the trusts say.
Species affected will include the dormouse and some bats and butterflies.
The Wildlife Trusts says that while some species are already moving, development and loss of habitat is preventing movement for others.
The voluntary organisation is trying to link up natural areas of woodland, heathland and pasture so creatures like pipistrelle and barbastelle bats and sand lizards can extend their habitats.
Wildlife made a similar move in search of food and homes following the last Ice Age, the trusts said.
John Everitt, the organisation's head of rebuilding biodiversity said: "This time there are unexpected barriers: cities, motorways and expanses of hostile countryside.
"We need to ensure that we give our wildlife room to move or its future is threatened."
Some animals are already extending their territories and moving to new parts of the country previously beyond their range, Mr Everitt said.
New species are also arriving, attracted by the UK's changing climate.
The hazel dormouse is one of the threatened species. It needs reasonably-sized blocks of hazel wood to survive but such areas are increasingly threatened by fragmentation, the trusts said.
Dormice need linked woodland to allow them to move between habitats, as they refuse to cross open ground.
Upland birds and animals such as the mountain hare which could migrate uphill may become isolated at the mountain tops, the trusts said.
A lack of snow could threaten birds such as the ptarmigan which turns white in winter to hide from predators.