 Because Ireland became isolated from mainland Europe by rising sea levels before the last ice age had completely finished , it has fewer land animal and plant species than Great Britain , which separated later , or mainland Europe . There are 55 mammal species in Ireland and of them only 26 land mammal species are considered native to Ireland . Some species , such as , the red fox , <unk> and <unk> , are very common , whereas others , like the Irish hare , red deer and pine <unk> are less so . <unk> wildlife , such as species of sea turtle , shark , seal , whale , and <unk> , are common off the coast . About 400 species of birds have been recorded in Ireland . Many of these are migratory , including the barn swallow . 
