Donald S. Heintzelman has been Associate Curator of Natural Science at the William Penn Memorial Museum and was Curator of Ornithology at the New Jersey State Museum. He is now a wildlife consultant, lecturer, and writer. He is an Audubon Wildlife Film Lecturer for the National Audubon Society, and has served as ornithologist on board the MS. Lindbiad Explorer on expeditions to Amazonia, Antarctica, and Galapagos. He is the author of Autumn Hawk Flights, The Hawks of New Jersey, Finding Birds in Trinidad and Tobago, and A Guide to Eastern Hawk Watching.