The Allen's swamp monkey (Allenopithecus nigroviridis) is a species of Old World monkey and the only member of the genus Allenopithecus. Phylogenetically, it is a sister clade to the guenons, but differs in dentition and habits.
Allen's swamp monkey was named after American zoologist Joel Asaph Allen.[1]
Allen's swamp monkey lives in the Congo Basin, the Republic of Congo, the west of the DRC, and Cameroon.[2] [3] It was recorded from Dzanga-Sangha Special Reserve in the Central African Republic in 2016.[4]
This monkey is a rather strongly built animal. The slight webbing of the fingers and toes point to its partially aquatic way of life. Allen's swamp monkey can reach a full body length from 45 to 60 cm, with a roughly 50-cm-long tail. Males, weighing up to 6 kg, are substantially larger than the females (up to 3.5 kg).
Allen's swamp monkey is a diurnal animal and regularly looks for food on the ground. It inhabits swampy, water-rich areas and can swim well, diving to avoid danger. It lives in social groups of up to 40 animals, communicating with different calls, gestures, and touches.
Its diet consists of fruits and leaves, as well as beetles and worms.
Little is known of the mating habits of this species. The females bear young, which are weaned around three months old and are mature after three to five years. Its lifespan can be as long as 23 years. Raptors, snakes, and the bonobo are the natural predators of Allen's swamp monkey. It is also hunted for its meat.