Traylor was Lieutenant with the marines and served on Guadalcanal during World War II in 1942 where he was awarded with the Silver Star medal.
As a Marine Corps officer, Mel was severely injured during the Battle of Tarawa in the Pacific theatre, where he lost one eye and suffered arm and upper body wounds during the famous beach assault.
After the war Traylor continued his work for the Field Museum of Natural History in Chicago, which he had started in 1937.
In 1960 he was among the members of the World Book Encyclopedia Scientific Expedition to the Himalaya led by Sir Edmund Hillary.
Traylor was among the authors (alongside Raymond A. Paynter, Ernst Mayr, G. William Cottrell, and James Lee Peters) of Check-list of Birds of the World, a standard reference work with sixteen volumes published between 1931 and 1987.