HEATH HEN (Tympanuchus cupido), a North American grouse, allied to the prairie chicken (q.v.) but smaller and inhabit ing wooded districts. Between 1800 and 185o the heath hen was found locally in southern New England and throughout the Middle States. It subsequently disappeared from all parts of its range except the island of Martha's Vineyard, Mass., where in 190 7 it had decreased to less than i oo living birds. Owing to protective measures then established its numbers increased, but in the spring of 193o only one bird was f ound.