Charles was born on July 14, 1924, in Longview, Texas. As a child in southern Georgia and Virginia, he envied explorers who discovered new oceans, new continents, and at least new mountains and rivers. His father, a professor of wildlife management, was a lifelong bird-watcher, so Charles grew up as a bird-watcher as well. He thought he would become an ornithologist, but in the summer between high school and college he joined an expedition from the University of Michigan’s Museum of Zoology, collecting mammals in the Southern Appalachians. He realized that his dream of discovering and naming new species could come true with mammals, but not with birds. He was born 200 years too late to name new birds!!!

He got his bachelor’s degree at Virginia Tech in 1944, but had to defer graduate school while he walked from Holland to Berlin as a rifleman in the 120th Infantry. When he returned from Europe after World War II, Alexander Wetmore, then secretary of the Smithsonian, hired him to collect birds and mammals on a naval icebreaker expedition to the Arctic. Wetmore had taken him under his wing at age nine as a promising young ornithologist, and when he went to the Smithsonian it was as a curator of birds.

Charles attended graduate school in his spare time and received his master’s degree in 1947 and his PhD degree in mammalogy in 1955 at the University of Michigan. His education was interrupted by four expeditions to the High Arctic, one to Labrador, one to Guatemala, and a seven-month expedition to the Kalahari Desert in southern Africa with Harvard anthropologists studying stone-age Bushmen. From the Arctic expeditions he described new taxa of varying lemmings and Arctic hares and became a curator of mammals at the Smithsonian. With ten years of annual expeditions he inventoried the mammals of Panama. On his first trip to Panama in 1957, an ornithologist friend, Karl Koford, gave him a mist net and he caught and named new species of bats after that. Ornithologists who had rigged mist nets to catch birds up to 30 meters in the forest canopy near Belém, Brazil, let him use their daytime bird nets to capture bats at night. That feat, and a paper he published in 1967 describing bats of the canopy, were not duplicated for the next 30 years.

From 1965 to 1968, the Defense Department contracted Charles to conduct a monstrous inventory of mammals, their ectoparasites, and their viruses in Venezuela, collecting 40,000 specimens in the Smithsonian Venezuelan Project. Soon after this followed the ten-year (1975-85) Barro Colorado Island Bat Project. With Al Gardner and Don Wilson he recorded 35,000 marks and 15,000 recaptures, the largest database of tropical bats ever amassed.

His nine expeditions from 1986 to 1993 to the little known islands of Bocas del Toro, in the Caribbean off the northwest coast of Panama, revealed them to be a hotbed of evolution. He named a new bat, sloth, armadillo, and agouti. In 1990, he met Elisabeth Kalko, a graduate student at the University of Tuebingen, Germany. She had at her disposal the world’s most sophisticated custom-made electronic equipment for recording the ultrasounds of bats. Her studies were revolutionary, but she needed his knowledge of tropical American bats, so he turned his interests to echolocation and foraging behavior of bats. They and their students had long-running studies of bat communities in Panama, Venezuela, and Brazil. Startling discoveries were commonplace, and they frequently turned up new species. He wasn’t born too late to be an explorer after all!! Along the way he published about 200 articles in scientific journals and a couple of books.

Two wives, Iracy Oliveira in 1951, a multilingual translator from Brazil, and Darelyn Weber in 1969, a botanist from Illinois, gave Charles two daughters, Rebecca and Rachael, and two sons, Ben and Tom. He had six grandchildren.

He was elected to the Washington Biologists’ Field Club in 1952 and was a very active member, best remembered as the preparer of roe shad and chair of the research committee.

Charles died on June 9, 2000, in Springfield, Virginia.