They are actually strongly-built, they have a gray-green skin but the face is red-shaded with hairy cheeks, plus, the body measurements range from 45 to 60 meters. Expectedly (like in so many kinds of animals), the males are bigger than the females.
The newborn Allen's Swamp Monkeys are weaned at two and a half months, but the breeding length of time is generally unknown. Its lifespan is capable of reaching up to 20 years. An Allen's Swamp Monkey is diurnal and they survive in packs consisting of at least forty members. (It is to be expected that many adult males are in a typical group.) It is quite amusing (and frustrating too, for the researchers) that notwithstanding the presence of literature expounding on Old World Monkeys, little could be proven about the Allen's Swamp Monkey's system. However, studies have been done on captured monkeys, and from all indications, these monkeys are quite social.
Regarding food, they forage both on soil and on water...and what exactly do they consume? Leaves, fruit and invertebrates, in other words...
According to studies still, their life is far from easy, they really have to survive. They are subjected to constant threat from predators such as snakes, eagles, etc. Snakes and raptors are counted as among the mortal enemies of this type of monkeys.
Interesting fact: These monkeys are capable of several facial expressions, like snarling, grinning and even grimacing.
The Allen's swamp monkey is listed as Near Threatened (LR/nt), is close to qualifying for or is likely to qualify for a threatened category in the near future, on the IUCN Red List of Threatened Species