Mark had an early introduction to the Lincoln Park Zoo having grown up across the street and literally visiting it every day as a youngster. His early memory is meeting zoo director Marlin Perkins on the grounds while Mr. Perkins was filming his television show Zoo Parade. He received his undergraduate degree from Southern Illinois University and graduate degree from Northeastern University. His zoo career started at the Children’s Zoo in 1967.
Jobs as an animal keeper, zoologist followed and in 1975 he became Curator of Mammals. In 2003 he retired as Abra Prentice Wilkin Curator of Large Mammals. As International Studbook Keeper for the Spectacled Bear he served from 1983-2003. The publishing and sharing of information was introduced early in his career and was culminated in the book, Ark in the Park, the History of Lincoln Park Zoo.
He is a co-founder of the Zoo & Aquarium Video Archive.