Heath hens once ranged along the Atlantic coastal plain and were common enough to be a cheap food. Hunting and habitat conversion pushed them back to Martha's Vineyard, and in 1908 Massachusetts established a reserve there around roughly fifty remaining birds. Protection worked at first, with the population climbing into the low thousands by 1916.
Then a sequence of blows landed. A fire during the breeding season destroyed nests and habitat, followed by a severe winter and an unusual concentration of northern goshawks. Blackhead disease, spread from introduced domestic turkeys, struck the survivors. The population never recovered, and the birds that remained showed a strongly skewed sex ratio and evident infertility.
The sequence became a textbook case in conservation biology. It illustrated that protecting a species in one place does not immunise it against stochastic events, and that a population reduced to a single site can be erased by a run of ordinary bad luck. The last known individual, a male tracked for several years, was seen on 11 March 1932.