[1][3] Elder worked from 1941 to 1943 as a game biologist for the Illinois Natural History Survey and from 1943 to 1945 as a pharmacologist doing research in chemical warfare in the University of Chicago's Toxicity Laboratory.
[1] In general terms William Elder's research interest was the physiology of wild birds and mammals as related to their productivity, populations, and management.
Specific research ranged widely, however, and included ornithology, hunting pressures in waterfowl, fertility in waterfowl, bats in Missouri, endangered species, the Hawaiian Nene goose (funded in 1956 by a Guggenheim Fellowship and a Yale-Bernice Pauahi Bishop Museum Fellowship), and elephants in Zambia (funded by a 1968 National Science Foundation Grant).
[4] In 1964 he received patent rights for an oral chemosterilant for feral pigeons and other nuisance birds.
Accompanied by their daughters, the Elders studied the endangered Nene goose in Hawaii, elephants in Zambia and Rhodesia (now Zimbabwe), and waterbuck in Botswana.