New colonies of the UK’s fastest declining mammal species have been discovered in the uplands of south Wales.

Usually found across riverbanks in Wales, water voles have now taken up habitat in the valleys, which could help prevent their local extinction.

Robert Parry, chief executive of the Initiative for Nature Conservation Cymru (INCC), described the discovery as “huge”.

Speaking to BBC Radio Wales Breakfast, he said: “We didn’t know they were up there, they’re on the verge of extinction, we’ve been looking for them for decades.”