Dryas monkeys are undeniably one of the most fascinating primate species you are likely to encounter during African safaris. Also known as Salonga monkeys, they are scientifically referred as cercopithecus dryas and inhabit areas of Congo Basin, mainly around the left banks of River Congo.
Dryas monkeys are little-known species of guenon although it is now established that they are categorized as Cercopithecus Salonga with their common name being Zaire Diana monkeys but were actually Dryas monkeys.
However, some older studies revealed that the Dryas monkeys are actually sub-species of Diana monkeys and are classified as C.diana dryas although are geographically restricted from any known Diana monkeys and prefer secondary forest locations much are also found within lowlands, swampy places as well as near Rivers of the Congo.
These primates were changed to IUCN’s Red List of critically endangered species in 2008. Much as data about the Dryas monkeys is still insufficient, it is evident that they are very extraordinary and their population is possibly less than 200 monkeys. They are mainly threatened by poaching for meat, habitat loss due to logging and many other human activities.
These exceptional primates show sexual dimorphism in that the adult male Dryas monkey are specifically characterized by their black muzzles, white whiskers and short facial beards. The dorsal surfaces of their bodies along with their coronal crowns are grayish chestnut in color. Not only that, they have white color on the ventral side of their tails, bodies, buttocks and bottom part of their limbs. The upper parts of their limbs have the same color as the rest of their bodies and are dark grey or black-brown in color.
The adult females as well as the infants have smaller parts of their bodies being white in color which is not the same as their shoulder areas or their buttocks. Another part of their body that is different is the upper side of their arms that are relatively lighter in color compared to the males.
Interestingly, Dryas monkeys are social primates that live in groups either comprising of their own species or groups of mixed species. Troops are made up of up to 30 members of their exclusive species and are comprised of one male, many females and several offsprings.
These primates are marked by sexual dimorphism and their body size of the Dryas monkeys varies from 40 to 55 centimeters without the tails while measure a total of 50 to 75 centimeters with their tails. All in all, adults weigh from four to seven kilograms depending on the sex.
Dryas monkeys are primarily vegetarians with their diet mainly comprising of young leaves, fruits as well as flowers but because most vegetarian foods are seasonal in nature, these extraordinary monkeys also feed on small invertebrates especially insects as a substitute.
When it comes to communication, the Dryas use both oral and visual means when communicating to their own species or with other monkey species. They sometimes use exceptional communication methods that include staring and head-bobbing which are used as a threat and sometimes are done with the mouth open. Additionally, presenting is another behavior used by female Dryas monkeys during the mating season, which they show the males when ready for mating.
Dryas monkeys reach sexual maturity at three years of age and their gestation period is five months whereby a single offspring is born. They use quadrupedal locomotion that occurs with a gait pattern involving two pairs of limbs.
Their lifespan is 10 to 15 years in the wild and still unknown in captivity because there are no Dryas monkey populations in captivity.