author
An ornithologist and natural history writer, he is best known for careful field studies of songbirds, especially the Bell Vireo. His work has been valued for its patient observation and clear scientific focus.

by Jon C. Barlow
Jon C. Barlow, also published as Jon Charles Barlow, was an American ornithologist whose writing centered on bird behavior, ecology, and natural history. He was born in Jacksonville, Illinois, on October 31, 1935, and died in 2009 at age 73.
His best-known book is Natural History of the Bell Vireo, Vireo bellii Audubon, a focused study of a small North American songbird. Beyond that work, he published on several bird species and contributed to ornithological research over many years.
From the sources available here, he appears to have been respected in the birding and academic ornithology world, including service as a fellow and former council member of the American Ornithologists' Union. I couldn't confirm a suitable portrait image from the pages I checked, so none is included.