He studied as an undergraduate at Cornell University, returning to complete his degree after a period of military service during World War II.

During his professional career, he worked as a faculty member and natural history museum curator at a number of public universities.

Most of Tordoff's research was on the evolution of finches, and he is most remembered for his role in the reintroduction of the peregrine falcon in the upper Mississippi valley.

With his father, a stonemason, he learned to hunt and fish, and spent much of his free time observing birds and other wildlife, afield with his dog.

While he was there, he met Robert M. Mengel (his lifelong best friend, later editor of the Auk), who encouraged his interest in ornithology, as did one of his professors, Arthur Augustus Allen.

In graduate school at the University of Michigan from 1947 to 1950 he studied ornithology under Josselyn Van Tyne and George Miksch Sutton, earning a Ph.D. with a thesis on the systematics of finches.

While at Kansas, he collaborated with a number of other ornithologists, including Mengel, Glen Woolfenden, and Norman A. Ford; together, they are said to have raised standards for ornithological museum work.

In 1957 Tordoff moved his family back to Ann Arbor where he replaced Van Tyne as a faculty member at the University of Michigan, becoming curator of birds at the Museum of Zoology.

During his time at Minnesota, he helped build the new Department of Ecology, Evolution and Behavior, and raised a large endowment for graduate work in the biological sciences.

[5] Pat Redig, one of his collaborators and the founder of the Raptor Center in St. Paul, called Tordoff the "heart and soul" of the peregrine restoration effort.

As part of this project, 1286 peregrine chicks were hatched and by 2008 Tordoff and his colleagues had established a population of 128 breeding pairs and growing in the upper Mississippi region.

A key part of their success arose from his idea to put peregrine nests on the top of skyscrapers in cities like Minneapolis.