The general term “camel” usually refers to either the one-humped dromedary camel or the two-humped Bactrian camel. Camels originated in the Old World, with dromedaries associated mainly with North Africa, the Middle East, and South Asia, and Bactrian camels associated with Central Asia. Mature males may weigh about 900–1,800 pounds depending on species, while females generally weigh about 800–1,300 pounds. Camels are tan, brown, cream, or dark brown, with long legs, padded feet, thick eyelashes, and high tolerance for heat, cold, drought, and sparse forage. Camels were introduced into the United States in the 1850s through the U.S. Army Camel Corps experiment and later became part of zoos, circuses, private ranches, and educational collections.