Internationally known as an expert on ornithology, one would have to look to John Audubon or Roger Tory Peterson to find another who has had more impact on bird study than Carl Welty.

Welty joined the Beloit College, Wisconsin, biology department in 1934. After a few years, he became disappointed in the lack of a current biology text on birds, so took on the job of research and wrote a book himself. Titled Life of Birds, it became the most widely used college textbook on ornithology in the United States and went through several revisions.

At their rural home in Turtle Township, Wisconsin, the Weltys established a wildlife refuge which was used as a learning center for students.