The vervet monkey
Also referred to as Chlorocebus pygerythrus, the vervet monkey belongs to the Old World Monkey family of Cercopithecidae that is native to the countries of Africa including Uganda where it is always encountered on Uganda safaris. The Vervet Monkeys feature five different Sub Species that include; Chlorocebus p. excubitor, C. p. hilgerti, C. p. nesiotes, C. p. pygerythus and C. p. rufoviridis and the one in Uganda features a distinct reddish coloured back that is dark towards the tail base.
The Vervet Monkey features a black face along with white hair fringe while the general hair color is greatly grizzed-grey. The male adult of all Vervet Species features a pale blue scrotum and has a red penis as can be seen on safaris in Uganda. The Vervet Monkey Species demonstrate sexual dimorphism where males have a long body height and weight. The mature males weigh between 3.9 – 8kg and feature and an average of 5.5kg with a body length in between 17 – 24 inch from the head top to the tail. The mature females weigh in between 3.4 – 5.3kg with an average of 4.1kg and the length of 11.8 – 19.5inches.
Regarding behavior, the Vervet Monkey males after attaining the sexual maturity migrate to an adjacent group and they often migrate with a brother or any other peer assumedly for protection against the aggression by females and males thriving in the new group. It can be noted that the groups that had already received new males would not exhibit a lot of aggression like those that have never. The female vervet monkeys remain in their respective groups for the rest of their life
Each sex features distinct dominant hierarchy and the male hierarchy is dependent on age, the length of stay in the group, the ability to fight along with the allies. The female hierarchy is determined by maternal social status. There are enormous sections of interaction that thrive between members that have the same rank or are closely related. .
For the unrelated members, there is always a female competition to groom the members of high ranking families with a target of gaining unlimited access to resources. Interactions of Vervet monkeys thriving in various families vary ranging from high aggressiveness to friendliness. Additionally, the members recognize cross group vocalizations and can identify from and to which monkey that the call made is intended even when it is made by the sub adult male that has a likelihood of transferring to different group. This demonstrates that the group individuals monitor actively the other group’s activities including the individual movement within the group. The internal group aggression is directed majorly at the lower ranking members and it can be noted that a member of 3 years and above is more likely to face a conflict. The conflict tend to arise when the member of the group aggress a close relative of another member. Additionally, both sexes can extend aggression to the members in which the two feature close relatives which were previously engaged in a conflict. This indicates not only intense recognition of both members and the associations between them.
Regarding the sounds and the offspring recognition, it can be noted that the Vervet Monkeys feature four (4) confirmed predators including the leopards, baboons, pythons and eagles. When each predator is encountered, a different alarm is made and the other members respond in line with the notified predator. It can be noted that Vervet Monkeys feature thirty (30) alarm calls. The mothers are able to identify the offspring by screaming alone. It can be noted that Juvenile Screaming will definitely create an elicit reaction among all the mothers.
The infants tend to attract the attention of other females in the group. The other females would always come to inspect the infant days after birth to at least once and would either touch or sniff. The Juveniles which have not yet experienced the menstrual do the all mothering of the Sibling whose mother has given birth to other infants. It can be noted that Juvenile females tend to discriminate and prefer the siblings from high ranking families. Additionally to note is that the grand children and grandmothers share one-quarter of their genes and thus the infants tend to approach more their grandmothers other than other female adults.
Regarding reproduction, the female Vervet monkeys feature no external signs that indicate that they are in menstrual period thus no clear social behavior of reproduction. It can be noted that the female vervet monkey can produce at any period of the year following a gestation period of 165 days. Normally, Single infant is produced but at times twins can be produced though rarely. The produced infant features a weight between 300 – 400g.
Regarding diet, the Vervet Monkeys are vegetarian and greatly consume wild fruit, leaves, flowers, seed pods and seeds. In the agricultural areas, the Vervet animals would definitely become problem animals as they raid on people’s crops like beans, young tobacco plants, peas, fruit, bananas, grains like maize among others. This is a common phenomenon among the communities that live around the Uganda safari destinations which are habitats to Vervet Monkeys. The Vervet Monkeys also consume termites and grasshoppers and they would also eat eggs and chicks of weaver birds and cattle egrets.
Regarding the distribution, the Vervet Monkeys thrive densely in the South and East of Africa stretching from Ethiopia to Somalia, South Sudan and Uganda through to South Africa. The Vervet Monkeys do not thrive in the west of the East African Rift valley where a closely related malbrouck exist. They thrive in savannah, coastal forests, woodland, riverine and mountains of up to 4,000m above sea level. It can be noted that Vervet Monkeys easily adapt and can thrive in secondary or vegetation that is fragmented among which include cultivated areas. They can can also thrive in rural and urban setting. They feature a home range of about 176ha with an average density of 54.68 animals/km². The vervets have also been introduced overtime in a range of areas including Ascension Island, Bermuda, Cape Verde, Barbados, Cuba, Bahamas, Jamaica, Haiti, Saint Kitts Dominican Republic, Nevis and Dania Beach in Florida.
The Vervet Monkeys continue to face issues with man and his activities including the habitat encroachment, sustaining accidents accruing from electric shocks and vehicles, poisoning and bullet killing, trapping for traditional medicine and bush meat not forgetting biomedical research. The Vervet Monkey is listed as Least Concern on the IUCN red list.
In Uganda, the Vervet Monkeys are common Species and travelers on safari in Uganda visiting destinations like Lake Mburo, Queen Elizabeth, Murchison Falls and Kidepo Valley National Parks is assured of increased chances to encounter them.