Four-horned chameleon
The four-horned chameleon ("Trioceros quadricornis"), also known as Eisentraut's chameleon, is a species of chameleon native to highland areas in western Cameroon and southeastern Nigeria. Taxonomy. The four-horned chameleon was first described in 1899 by the naturalist Gustav Tornier. There are three subspecies, including the nominate. Distribution and habitat. The four-horned chameleon is found only in some highland areas associated with the Cameroon line across Cameroon and eastern Nigeria; its range includes the Western High Plateau, the Bamboutos massif, Mount Manengouba, Oku Massif, the Bakossi Mountains including Mount Kupe, and the Obudu Plateau  in Nigeria. T. q. eisentrauti in particular is endemic to the Rumpi Hills of Cameroon. Overall, T. quadricornis has an extent of occurrence of 13,300 km2 and an inferred area of occupancy of 1,000 km2. The species is primarily associated with relatively intact montane forest with limited human activity, where it has a relatively restricted elevational range (1150 to 2400 metres). Research suggests that this is likely to reflect competition with other chameleon species rather than physiological tolerances. The type locality for the species is Mount Manegouba in Cameroon. Description and behavior. Like many other chameleons, the four-horned chameleon  has a prehensile tail and single claws on its toes. It usually has four prominent horns, but sometimes two are present with up to four adjacent reduced horns; adults typically grow to a length of 10 to 14 inches. Male four-horned chameleons have a prominent hemipenal bulge and a gular beard, while some female four-horned chameleons have one horn or even two horns on the tip of the snout. The species almost exclusively feeds on arthropods. Conservation and threats. Because of its small and fragmented range coupled with numerous threats to its population, the four-horned chameleon is  ranked Vulnerable by the International Union for Conservation of Nature. There are concerns that logging and agricultural expansion may contribute to deforestation and potentially threaten the status of the species by degrading its habitat; in addition, despite its status as a protected Class A species in Cameroon, its intensive exploitation by the pet trade has caused significant population declines in some cases.