Curatorial trainee New York Zoological Society, Bronx, 1967-1969, assistant curator, 1969-1971, associate curator, 1971-1974, curator, 1974-1986, curator, chairman department ornithology, since 1986. Consultant United States Fish and Wildlife Services. Board directors American Pheasant and Waterfowl Society.
Founding director Research and Conservation Foundation Papua, New Guinea. Director AAZPA, 1984-1987, legislation committee chairman, 1979-1984, conservation and management committee chairman, 1984-1990. Chairman International Union for Conservation of Nature/ICBP Parrot Specialist Group, 1987-1991.