The Soays are particularly hardy and have been allowed to become largely feral. The breed is listed in "Category 4: At Risk" by the Rare Breeds Survival Trust, because there are only between 900 and 1500 registered breeding Soay ewes. The Soay is distinct from two other short-tailed breeds also associated with St. Kilda: the Boreray (from Boreray, another of the islands, and formerly also living on Hirta), and the "St. Kilda", a former name for the Hebridean sheep (which is probably not from St. Kilda at all).