Species Fact Profile: Allen's Swamp Monkey (Allenopithecus nigroviridis)

                                                    Allen's Swamp Monkey

                                                Allenopithecus nigroviridis (Pocock, 1907)

Range: Upper Congo Basin of Central Africa (extreme southern Cameroon and Central African Republic, northeastern Republic of Congo, northwestern Democratic Republic of Congo)

Habitat:  Lowland Swamp Forest

Diet: Fruits, Leaves, Seeds, Small Animals

Social Grouping: Groups of up to 40 individuals (one report of a group of 85) with multiple members of both sexes.  These larger troops may break up into smaller foraging parties, practice social grooming to strengthen group ties

Reproduction:  Breed year round.  Thirty-day estrus cycle.  Display sexual swelling coinciding with ovulation, more like the mangabeys than the guenons.  Females give birth to a single young (very rarely twins) after a gestation period of 5-6 months.  Neonates weigh 240-450 grams at birth.  Young are weaned at 3 months.  Sexual swelling begins in females at 2.5-3.5 years old, begin giving birth at 4 years old; males reach maturity at 5 years

Lifespan: 25-28 Years

      Conservation Status: IUCN Least Concern, CITES Appendix II

• Body length 45 centimeters with an additional 45-50 centimeters of tail.  Weigh 3.4-5.9 kilograms, with males being notably larger than females.  The body is stout.  The fingers and toes are partially webbed (juveniles tend to more aquatic than adults)
• Fur is a mixture of brown, green, and gray with black bands and golden flecks, notably longer around the neck and shoulders.  Underbelly is white.  The face is black with a reddish chin, with long bundles of hair at the cheeks
• Active by day.  Spends much of its time in the trees, but comes to the ground to feed.  Good swimmer, capable of diving to avoid danger (sleep beside and over water as an anti-predator defense system)
• Primarily foraging on the ground.  Food items can be stored in cheek pouches (will sometimes rob each other’s pouches).  They will also enter water for forage for fish and small aquatic invertebrates (shrimp, snails) in the shallows
• Some tool use demonstrated – one zoo specimen threw hay on the surface of the water to create a shadow, which would attract fish that he would then seize and eat
• Predators include raptorial birds such as crowned eagles, large snakes, and bonobos. 
• Vocalizations include a high chirp as an alarm, a long squeal of excitement, and a deep gobble from males, thought to be territorial.  Threats consist of stares and teeth displays
• Have been observed casually socializing with and foraging alongside other guenons, such as Wolf’s guenon and Schmidt’s red-tailed guenon, as well as black mangabey and talapoin, but do not seem to go out of their way to facilitate such interactions.   One report of a hybrid produced in captivity with a male Allen’s swamp monkey, female vervet
• Species and genus are named after American zoologist Joel Asaph Allen.  It is the only member of the genus Allenopithecus (“Allen’s Monkey”), which differs from the closely related guenons in both its dentition and its habits, as well as by having fewer (48) chromosomes.  Species name refers to greenish highlights in fur
• Population believed to be decreasing, though apparently abundant in some protected areas).  Primary threat is hunting for the bush-meat trade.  Also sometimes killed in retaliation for crop raiding or captured for the pet trade.  All of this is facilitated by logging, which increases human access to their habitat.  Habitat loss itself is not a major threat to this species, as their preferred habitats are very swampy and unsuitable for logging or for agriculture