Over 20 breeds of British farm animals became extinct between 1900 and 1973, according to the Rare Breeds Survival Trust. Others came close: At one point, the population of Norfolk Horn sheep, which can jump three feet into the air, had dropped to only 14 animals.
The trust encourages the preservation of rare breeds in the United Kingdom, and the American Livestock Breeds Conservancy does the same in this country. Here are some of the sheep that Margaret Russell uses:
Balwen: These sheep come from a single valley in Wales, and a particularly harsh winter in 1947 nearly wiped them out, leaving only one surviving ram. Local farmers slowly rebuilt the herd over the next 20 years, and in the 1970s farmers in other areas began raising them as well. The breed is now classed as "vulnerable" and is protected by the Balwen Welsh Mountain Sheep Society.
Grey-faced Dartmoor: This breed is descended from native sheep who grazed the heaths of Dartmoor in the 17th and 18th centuries. Its numbers declined when the breed fell out of fashion in the 1940s, and it is regarded as "at risk."
Jacob: A sheep in cow's clothing, the Jacob has a strong black-and-white pattern most people associate with cattle. Jacob sheep are more curious and agile than other breeds, perhaps because they are an "unimproved" breed that have not been bred with other types. They are rare in this country but well established in Britain.
Llanwenog: This Welsh breed is descended from the extinct Llanllwni breed and arose in the 19th century in Wales. With only 1,000 ewes in 1997, it is classed as "at risk."
Manx Loghtan: This reddish-brown sheep is descended from early wild British sheep and can have up to six horns. It is classed as "at risk," with 1,540 ewes in British Isles in 1997.
Shetland: The smallest British breed, Shetlands were probably brought to the Shetland Islands by Vikings over 1,000 years ago. The breed is classed as "recovering" in the U.S. and a minority breed in Britain, where there are over 2,000 Shetland ewes.
Soay: This is a primitive breed that was well established in the British Isles at the time of the Roman occupation. These sheep were probably domesticated in prehistoric times but are now regarded as feral. Small and light brown, they shed their fleece in the spring and prefer to graze singly rather than in flocks. They are classed as "at risk" in Britain, with only 697 females found in a 1997 survey.