Agile Mangabey
Species Name: Cercocebus agilis
The Agile Mangabey is another Old-World monkey of the White-Eylid Mangabey group mainly found in swampy forests. Due to habitat loss, mangabeys are now listed as endangered, both male and female.
Allen’s Swamp Monkey
Species Name: Allenopithecus nigroviridis
Allen's swamp monkeys are small, stocky monkeys with gray to brown fur and long tails. These highly social primates live in the swamp forests of central Africa, where they mostly spend their time in the trees. It was named after Joel Asaph Allen, an American zoologist.
Alta Floresta Titi
Species Name: Plecturocebus grovesi
The Alta Floresta titi is a distinct but unnamed form of titi (Plecturocebus) rediscovered in 2011 in Chapada dos Parecis, a plateau in the far south of the Brazilian state of Rondônia. This species lives exclusively between the Teles-Pires and Juruena rivers in Mato Grosso.
Amazon Black Howler
Species Name: Alouatta nigerrima
Amazon Black Howler is a New World tropical arboreal characterized by densely furry, prehensile tails, all-black faces, a stocky build, relatively large size, and loud howls. According to researchers, its howl sounds like a strong wind blowing through a tunnel can be heard more than two miles away.
Andean Night Monkey
Species Name: Aotus miconax
Andean night monkeys are a genus Aotus, commonly known as nocturnal monkeys or the Peruvian night monkey. Species in this genus are the only truly nocturnal monkeys in the world. Andean night monkeys are not sexually dimorphic as males and females look very similar.
Andean Saddle-back Tamarin
Species Name: Leontocebus leucogenys
The Andean saddle tamarin, also known as the saddleback tamarin (formerly known as the brown-mantled tamarin), is a New World monkey species. Andean saddleback monkeys are considered "phyletic dwarfs," meaning their small size is related to their evolutionary development.
Angolan Colobus
Species Name: Colobus angolensis
The Angolan Colobus is a conspicuously-patterned monkey with a very long tail that helps it maintain its balance as it moves quickly through the trees. Although the species is named after Angola, it's rare in this country.
Angolan Talapoin
Species Name: Miopithecus talapoin
Also known as the Southern talapoin, Angolan talapoin is a primate species in the Cercopithecidae family. Tail color varies from grayish-black to brownish-black above and is yellow or yellowish-gray below. The Angolan talapoin monkeys are among the smallest species of Old-World monkeys.
Annamese Silvered Langur
Species Name: Trachypithecus margarita
The Annamese langur is another Old-World monkey in the subfamily Colobinae. Annamese langurs are covered in thick, gray fur. They have dark faces, and the space around the eyes is pale and forms a ring, often in the flesh. Trachypithecus margarita is a monotypic species as it has no subspecies.
Aracá Uakari
Species Name: Cacajao ayresi
The Aracá uakari, also called the Ayres black uakari, is a newly described monkey species endemic to the northwestern Brazilian Amazon. The species was found by Jean-Philippe Boubli of the University of Auckland after following local Yanomamo Indians on their hunts along the Aracá River, a northern tributary of the Negro River.
Arunachal Macaque
Species Name: Macaca munzala
The Arunachal macaque is a comparatively sizeable brown primate with a relatively short tail. Arunachal macaques were first classified into Cercopithecidae's taxonomy in 2005 by primatologists Madhusudan and Mishra.
Ashy Black Titi
Species Name: Plecturocebus cinerascens
The Ashy black titi is a species initially described in 1823 as Callicebus cinerascens. Ashy black titi monkeys live in small families comprising a monogamous pair and their young. Adult males tend to carry their infants unless the mother is nursing.
Ashy Red Colobus
Species Name: Piliocolobus tephrosceles
The Ashy-red Colobus or Ugandan red Colobus is an endangered species of red Colobus endemic to Eastern Africa. Like other colobus monkeys, Ashy Red has small thumbs that allow it to comfortably grip branches and swing nimbly through the canopy. In 2001, the ashy-red Colobus was recognized as a separate species.
Assam Macaque
Species Name: Macaca assamensis
The Assam macaque, also known as Assamese macaque, is a macaque of the Old-World monkey family endemic to South and Southeast Asia. Assam is another state in India. Eating everything from fruits to 55 types of flowers, leaves, seeds, and bark, these macaque monkeys adapt their diet to suit their habitat.
Atlantic Titi
Species Name: Callicebus personatus
The Atlantic titi, also known as the masked titi, inhabits the rainforests of the Atlantic coast of Brazil east of the Andes in the states of Bahia, Espírito Santo, northwest of Minas Gerais, north of Rio de Janeiro, and São Paulo. This species, found nowhere else in the world, inhabit the tropical forests of Brazil's Atlantic coast east of the Andes.
Azara’s Night Monkey
Species Name: Aotus azarae
Azara's night monkeys, also known as southern night monkeys and Azara's owl monkeys, are native to the Gran Chaco region of South America, a vast area with many different ecosystems, from savannas to grasslands to dry spiny forests and gallery forests. Genetic testing has shown that the males of this species mated pairs are the fathers of the babies they care for.
Suggested Reading: All Different Kinds of Monkeys