Barbara Brown's titi monkey (Callicebus barbarabrownae), also popularly known as the blond titi monkey or northern Bahian blond titi, is a species of titi, a type of New World monkey. This critically endangered species is endemic to the Caatinga in northeastern Brazil, and it is estimated that less than 250 mature individuals remain. It is named after the zoologist Barbara Elaine Russell Brown. Home range The blonde titi monkey is listed as Critically Endangered due to small population size. The blond titi monkey is endemic to the Atlantic forests of eastern Brazil, where it is found in the coastal highlands of Bahia and Sergipe States. Most of their population is found between the Paraguaçu River (north) and Salvador (south), and west towards Mirorós. The estimated population is 260 individuals and is decreasing. C. barbarabrownae has been listed among the World’s 25 Most Endangered Primates in 2012. Habitat and ecology The blond titi prefers habitats in caatinga a dry scrubland with preferences for dense arboreal caatinga. They do tend to be largely arboreal forest dwellers, and the blond titi monkey probably rarely descends to the ground. They are small in size and are agile primates, they are good climbers through the branches on all four limbs, using their rear limbs to jump long distances, grasping onto branches with leading forehands. While resting, they hunch their body, hanging the tail over a branch. . Biology The titi monkeys are most active at dawn and dusk foraging for fruits, leaves and insects, and rest at midday. The males will lead the group while foraging, communicating to the rest of the group with a wide array of vocalizations and visual signals. Titi monkeys are monogamous, with groups consisting of strongly-bonded parents and their offspring. Partners often reinforce the pair bond by perching side by side and entwining their tails. Females give birth annually, during the wet season, to a litter of just one, after a gestation period of five to six months. Juveniles grow rapidly to reach adult size within ten months. Major threat(s) Since the titi monkey inhabits a region of Brazil they are subjected to a widespread of deforestation and habitat fragmentation. Cattle ranching, agriculture and continuing urbanization are the main threats. The area is in rapid development facilitated by an extensive network of highways. Other threats include potential dangers from roads and power-lines and predation by domestic pets. This species occurs