The Hirta population is unmanaged and has been the subject of scientific study since the 1950s.
The Soay Ovis aires has the most primitive appearance of any British sheep breed and takes its name from the island of Soay in the St. Kilda group. Soay means “sheep island” in Norse which suggests that there have been sheep on the island since at least the time of the Vikings. 107 Soays were transported to the island of Hirta in 1932, two years after the last human inhabitants had left and have been maintained as a feral population ever since numbering around 1500 sheep nowadays. Over the years Soays have been imported on to the mainland but remain rare. Wool is shed naturally each year and is used for speciality hand knitting.