 He graduated with a Bachelor of Arts in 1958 and continued graduate education under animal behaviorist Eckhard Hess, studying imprinting in birds.After discovering he was allergic to birds, he switched the focal species of his research on animal behaviour to grey wolves donated by the Brookfield Zoo and housed in an enclosure on his property near Battle Ground, Indiana.He received his PhD in 1962 but would continue study on the captive wolves, expanding as more animals arrived.