 The St Kildans kept up to 2 @,@ 000 of a different type of sheep on the islands of Hirta and Boreray . These were a Hebridean variety of the Scottish Dunface , a primitive sheep probably similar to those kept throughout Britain during the Iron Age . At the time of the evacuation all the islanders ' sheep were removed from Hirta , but those on Boreray were left to become feral , and these are now regarded as a breed in their own right , the Boreray . The Boreray is one of the rarest British sheep , and is one of the few remaining descendants of the Dunface ( although some Scottish Blackface blood was introduced in the nineteenth century ) . 
