Goodfellow began his career as a wildlife collector by collecting specimens for museums, but later concentrated on capturing live birds for private aviaries.
[1] Over forty years of collecting expeditions he travelled through Central and South America, Taiwan, the Philippines, New Guinea and Melville Island, off northern Australia.
[2] Goodfellow's best-known ornithological achievement was the scientific discovery of the Mikado pheasant in the central mountain ranges of Taiwan and its introduction to aviculture.
In about 1906 he secured the type specimen, comprising two long black tail feathers obtained from one of his porters who was wearing them in a head-dress.
[3] On a later visit to Taiwan he obtained eleven live birds, eight males and three females, which were taken to Britain and bred successfully in captivity.