The Black and White Colobus
The Black and White Colobus : (colobus guereza) also termed to as an Old World monkey is a native to central Africa. They have a scientific name known as the mantled guereza, the species derives the word “mantled” from its mantle, the long silky white fringe of hair that runs along its body. And derives “Guereza” from the native word in Ethiopia meaning monkey. Additionally the scientific name colobus derives from a Greek word “kolobus” meaning “Mutilated” which refers to its lack of thumbs. The species has a distinctive black and white coloration, with long white fur on their backs. The black and white colobus are unusual in a way that they possess no thumbs and only have four fingers on their hands though some individuals will have a partial thumb that is not used. Their habitat ranges from tropical forests to dry forests and scrublands and are generally found in high density forests where they forage on leaves, when in forests they are highly arboreal and spend most of their time in the trees. Howsoever in less dense forests, they will travel along the ground and spend most their time searching for food and resting. In Uganda, they can be viewed in different national parks such as Kibale National Park, Queen Elizabeth National Park, Semuliki National Park, and Murchison falls National Park among others and are noted among the popular primate species sought after on wildlife safaris in Uganda.
The black and white colobus is a heavy bodied animal with a long tail. Guerezas are slightly sexually dimorphic in a way that males weigh more than females. They possess only four fingers on each hand, the thumb is absent or represented by a small phalangeal tubercle that sometimes bears a nail. It is believed that the loss of the thumb may be an adaption for quick movements through and along the trees. The stomach of the colobus guereza is complex and subdivided by a partition into 2 for the fermentation of foliage by anaerobic bacteria and have large salivary glands that provide a buffer fluid between the two regions of the stomach. The coloration of the fur is distinctly white and black, the face is grey, no fur, face and callosities are surrounded by white. The coat is glossy black along with a U-shaped white mantle of varying length harbored on both sides. The outside of the thigh is variably whitish and the tail is nearly whitish or yellowish in color ranging from tip to base however the tail also has a large white tuft at the end. The skull is prognathous hence the lower jaw projects beyond the upper and the nostrils are more or less lengthened by an extension of nasal skin. In addition the nose nearly touches the mouth. The molar teeth of the colobus have pointed cusps, the inside of the upper molars and the outside of the lower molars are slightly convexly buttressed. The enamel on the inside of the lower molars incisors is thick and there is a lateral process on the lower second incisor.
Colobus Guereza have a polygamous mating system and it has been studied that there seems to be little or no reproductive seasonality in most populations of the colobus, however they tend to have a birth peak, timed out so that weaning corresponds with the greatest seasonal abundance of solid food. There is no distinct breeding seasons however most mating definitely occurs mainly in the rain season. The full sexual maturity of the male guereza is always at the age of 6 and in females is 4 years of age and each adult female suckles her infant for over a year and produces one young every after 20 months of her gestation period which is about 6 months before giving birth again. When giving birth, females usually tend to give birth in private, and solitude, however they have been noticed helping themselves when giving birth. At birth, the infants are about 20cm in head-body length and weight about 0.4 kg, eyes are open and the infant clings to the mother’s or fathers stomach however the weaning age is not known. Other troop members often handle very young infants and the infants are carried on the other’s abdomen where it clings to her fur. Generally both the male and the female take part in the parenting of the child, females remain in their natal group meaning that mothers and daughters have life-long relationships. As it matures, it spends a lot of time playing with its mother and certainly other adults and at about 7 months of age, it then begins playing with other juveniles.
Guereza are typically diurnal and are highly arboreal residents of deep forest and they live in sexually mixed groups ranging from 8 to 15individuals with normally only one fully adult male (dominant) and three or four reproducing females, adolescents and infants. Each troop has its own territory which is well defined and defended from other troops and adult troop members specifically males make croaking roars that can be heard resonating throughout the forest. The fixed core of the mixed group consists of the females, who remain in the group of their birth for life. These females are expected to be close relatives that display their friendly intragroup relationships, marked by mutual grooming and well-developed “infant transfers”. This consists of an infant being handled by a number of females soon after birth and carried as far as 25m from its mother. The colobus spend much of their time sitting in the tops of trees, and they take turns sleeping at night so that at least one individual is awake at all times to watch over for predators. There is always no true leader of a group howsoever strong males usually take leadership roles. Intergroup relationships are not friendly among mixed groups of guerezas, which live in well-defined territories of about 32 to 40 acres. Territories may overlap marginally they are vigorously defended by males with leaps and cries, hand-to-hand communication, roars and occasional chasing and fighting. Additionally the displays of the white fringe fur flapping up and down serve as a warning to other animals whereas some groups do share water holes and other essential resources. In order to have defense against air predators like eagles, the species simply attempts to avoid and hide from them however they also at times been seen in fights against other types of animals a practice termed to as baiting.
These colobus lives up to 20 years typically in the wild and have been known to live 25-30 years in captivity. Normally predators of black and white colobus are leopards, crowned hawk eagles and occasionally chimpanzees.
Male guerezas roar loud nocturnal and utter dawn choruses as means of spacing groups, five vocal sounds have been recorded that’s to say snorts, honks, screams, purrs and roars. Additionally, in terms of vocal communication, visual signals such as facial expressions, flapping of fringe fur and body postures are used in aggressive communication between different groups. Tactile communication in this species includes fighting, grooming and playing.
Guerezas are the second most folivorous species among the colobus and thier diet comprises of primarily leaves with nearly of young unripe ones, mature leaves, fruits, leaf buds and blossoms. However this distribution is highly varied seasonally and geographically thus at times mature leaves may account in the diet. They are strictly leaf eaters that are less vulnerable to seasonal fluctuations. Additionally, they get water from dew and the moisture content of their diet or rainwater held in the tree trunk hollows and spend most of their days eating, relaxing almost like humans.