Attempts were made in the 1930s and thereafter to eliminate these animals as pests in the United States, particularly in [[Yellowstone National Park]], where it had been considered that stray wolves regularly fed upon livestock. By the time they were included in the ''Red Data Book'' in 1973, they were severely restricted in range throughout North America and Europe, and classified as an endangered species. The last wolf in [[England]] had died long before, bagged on the fringes of Hounslow Heath, Middlesex, in 1756. | Attempts were made in the 1930s and thereafter to eliminate these animals as pests in the United States, particularly in [[Yellowstone National Park]], where it had been considered that stray wolves regularly fed upon livestock. By the time they were included in the ''Red Data Book'' in 1973, they were severely restricted in range throughout North America and Europe, and classified as an endangered species. The last wolf in [[England]] had died long before, bagged on the fringes of Hounslow Heath, Middlesex, in 1756. |