James Cowan Greenway (7 April 1903 – 10 June 1989) was an American ornithologist. An eccentric, shy and sometimes reclusive man, his survey of extinct and vanishing birds provided the base for much subsequent work on bird conservation.
Greenway was born in New York City, the son of a wealthy physician, and grew up on the family estate at Greenwich, Connecticut. He was educated at Phillips Exeter Academy, graduating in 1922, and Yale University from which he obtained an Bachelor of Arts degree in 1926. He then worked for a few years as a reporter for the Brooklyn Eagle newspaper.
In 1929 Greenway became a partner in the Franco-Anglo-American Zoological Expedition to Madagascar. The expedition was sponsored by the Muséum national d'histoire naturelle in Paris, the British Natural History Museum in London, and the American Museum of Natural History (AMNH) in New York City, and led by French ornithologist Jean Delacour. Greenway took part in the expedition from April to August 1929, after which he and Delacour left Madagascar for Delacour’s fifth expedition to Indochina, where they collected zoological specimens in Tonkin and Annam.
In 1932 Greenway joined the Museum of Comparative Zoology (MCZ) at Harvard University as Assistant Curator of Birds until 1952 and then, succeeding James Lee Peters, as Curator until 1960. During the 1930s he participated in several collecting expeditions to the Caribbean, especially the Bahamas. In 1936, he and one of his brothers flew across the Bahamas from north to south, and were the first to land a plane on East Caicos in the Turks and Caicos Islands; the school children were let out of school for the special occasion. Greenway also took part in Delacour’s seventh expedition to Indochina in 1938–1939.