Rare pine marten 'photo-bombs' red squirrel survey
30 April 2014 Last updated at 18:26 BST
Scientists behind a red squirrel monitoring project in County Fermanagh have been surprised after finding an even more elusive mammal has been 'photo-bombing' their research.
Pine martens have been spotted by cameras in the Fermanagh woodlands, more than red or grey squirrels.
Julian Fowler reports.