Southern brown howler
The southern brown howler is a monkey subspecies of brown howler native to southeastern Brazil and far northeastern Argentina. Gregorin, 2006, considered the southern brown howler to be a separate species, Alouatta clamitans, but this has not been universally accepted.
Distribution and habitat
The southern brown howler is found in the Atlantic forests of eastern Brazil where it occurs in the states of Espírito Santo, Rio de Janeiro, Minas Gerais, São Paulo, Paraná, Santa Catarina and Rio Grande do Sul. Its range extends southwards as far as the Camaquã River and eastward to Misiones Province in Argentina. Its northern extent is unclear, but may be the Doce River or the Jequitinhonha River. Habitats include lowland, sub-montane and montane forests, and it is tolerant of disturbed habitats and human encroachment.Ecology
Howlers move around in small troops, consisting of a dominant male, several females and a number of juveniles. The monkeys are so called because of the loud calls made by males, more roar than howl, which can be heard a mile or more away, mostly at dawn and dusk. The throats of males have enlarged vocal sacs and large tracheal cartilages which act as resonators to amplify the sounds. The diet of these monkeys consists mostly of leaves, supplemented by flowers and fruit, and these foods being plentiful in the rainforest, the territories defended by the troops are small. Rival troops howl at each other but territorial disputes are mostly settled vocally, without the monkeys needing to meet face to face.In the Araucaria pine forests of southern Brazil, the chief predators of these monkeys are ocelots, cougars, and jaguars, as well as the larger birds of prey.