His Ph.D. was completed in May, 1991 at University of Kansas where he graduated with honors in Biology studying with advisor Dr. Kenneth B. Armitage.

In 2000, John left Oregon to join the faculty of the wildlife program at the University of Arizona and to serve as the Director of the Mt.

John Koprowski's research extends from his early experience with the behavior and ecology of wildlife in human impacted environments, often using community-based conservation to enhance success.

His work has focused on the conservation of biodiversity, particularly mammals, and elucidating patterns in social and mating systems as well as the population response of wildlife to stressors in their environment such as non-native species, human development, disease, fire, and climate change.

Squirrels were one of the few species that could be found in an inner, highly urbanized, suburb and became a fascination for the young naturalist; the taxonomic group remained a research interest in his career.