Clarence Cottam, biologist and conservationist, son of Thomas P. and Emmaline (Jarvis) Cottam, was born in St. George, Utah, on January 1, 1899. He was raised in this rural community and worked as a farm and ranch hand. His concern for wildlife led him to dedicate himself to wildlife research and conservation. He attended Dixie College in 1919–20 and the University of Utah in the summer of 1923; he graduated A.B. from Brigham Young University in 1926 and received a master's degree there in 1927. While there he was principal of the Alamo, Nevada, schools. From 1927 to 1929 he was instructor of biology at Brigham Young. In 1929 Cottam became a junior biologist on the research staff of the United States Biological Survey in Washington, and by 1934 he was senior biologist in charge of food-habits research. He earned his Ph.D. at George Washington University in 1936. In 1939 the United States Biological Survey became the United States Fish and Wildlife Service, and Cottam eventually served as chief of wildlife research in the agency. He became assistant director in 1945 and remained in that position for eight years. In 1954, after twenty-five years of government work, he returned to Brigham Young University as professor of biology and the dean of the College of Biological and Agricultural Sciences. A year later he agreed to help organize and to become the head of the Rob and Bessie Welder Wildlife Foundation and Refuge in Sinton, Texas, where he served as director until his death.
Cottam was involved in conservational causes and affiliated with several conservational and humanitarian organizations. In 1969 he fought against the use of a highly toxic pesticide in Texas, arguing that it would harm the Gulf Coast bays. He also helped research the long-range effects of DDT and campaigned for the control of its use. He was involved in the establishment of the Island National Seashore on the Gulf of Mexico and the expansion of the Aransas National Wildlife Refuge. He was an advocate of the cause to save the whooping crane, bald eagle, brown pelican, and other endangered species. Among his many memberships, Cottam belonged to the Wildlife Society of America (president, 1949–50), the National Parks Association (president or chairman of the board, 1960–74), the Outdoor Writers Association of America, the Ecological Society of America, the Soil Conservation Society of America, the American Forestry Association, the Society for Range Management, the National Academy of Sciences, the Texas Academy of Science, and the Texas Ornithological Society (president, 1957). His published works include Food Habits of North American Diving Ducks (1939), Insects: A Guide to Familiar American Insects (1951), Whitewings: The Life History, Status, and Management of the White-winged Dove (1968), and numerous magazine articles for such periodicals as Audubon Magazine, National Parks Magazine, and Living Wilderness. Cottam's honors include the National Audubon Society's Distinguished Service Award (1961) and a citation from the National Wildlife Federation in 1964 for his work in conservation. He also received similar recognition from the Audubon Naturalist Society, Brigham Young University, and the Department of the Interior.
On May 20, 1920, Cottam married Margery Brown; they had four daughters. Cottam was a Mormon. He died on March 30, 1974, and was buried at Orem, Utah.