The robust cottontail or Davis Mountains cottontail (Sylvilagus robustus) is a species of cottontail rabbit endemic to four mountain ranges in the southwestern United States and adjacent Mexico. It was long considered to be a subspecies of the eastern cottontail (S. floridanus), but has recently been promoted to species level due to morphological analysis. Genetic data have confirmed the uniqueness of S. robustus. S. robustus and the subspecies of S. floridanus are distinguished primarily by size, dental, and cranial differences. These rabbits typically average a total length of 42 cm, and weigh between 1.3 and 1.8 kg. This species is restricted to dry, brushy, mountains at elevations above 1500 meters. Despite its rarity, currently no governmental agency provides protection or listing for