Colobus Guereza

Kristen Lichvarcik


Photo taken at Jungle Larry's Carribean Gardens


Class Mammalia,



Worldwide

Geographic Distribution

The Colobus are located in central and west Africa, but mainly across equatorial Africa from Nigeria to Ethiopia, Tanzania, Uganda and Kenya

Environment

They live in tropical forests and woodlands around rivers and in secondary forests. The

Colobus Monkey is arboreal and exists mainly in higher levels of trees. They will come down to the ground sometimes, however. Because they are a tree species, they live in forests where there are not many other animals that live in trees and there is a longer dry season (Rowe 1996: 170).

Social Groupings

Colobus Monkeys live in small troops ranging in size from 3 to 15 members

(AZA 1998: 1), however, there are usually 6 to 9 members (Species Data Sheet 1998: 1). This grouping usually consists of one adult male, three or four females and their young offspring (Colobus Monkey, Zoological Society 1996). Sometimes there are more than one adult male and sometimes there are no females, but these types of groups are not thought to be permanent

(AZA 1998: 1). Females of the group remain in the troop for life but the male must leave at maturation (Colobus Monkey, Zoological Society 1996). The single adult male "acts as the lead animal" but other than that there is not really a hierarchy that is adhered to (Colobus Monkey, Phoenix Zoo 1996).

They occupy a territory of up to 40 acres and are very protective of this area

(Species Data Sheet 1998: 1). They are territorial and will chase away any other groups that enter its area (Rowe 1996: 170).

Features

The Colobus belong to a larger group known as Old World Monkeys. Old World

monkeys are found in the southern Asia and in a large part of Africa and are quadrupedal as well as mostly arboreal (Jurmain 1998: 161). The eat a lot, sleep a lot and sit with an erect posture which hardens the skin on the behind into ischial callosities (Jurmain 1998: 162). Colobines are Cercopithecidae and the other members of this group, the cercopithecines are more omnivorous and have cheek pouches which the Colobus are not and do not have, respectively (Jurmain 1998: 161).

The Colobus Guereza are one of eight species of Colobine and there are six subspecies of Guereza (Chargot 1998: 1). These subspecies include the caudatus and the occidentalis

(AZA 1998: 1). The young colobus is completely white. When they get older they have a thick, glossy, black and white coat. Their faces are void of hair but are surrounded by white fur. They also look like they are wearing a cap, which is actually black fur. The rest of their bodies are covered in black fur except for a section of their backs descending from their shoulders, which is white. They have a long tail which varies in length and the amount of white on the tail can help classify subspecies along with the mantle (AZA 1998: 1). They have four fingers which can grasp but their thumb is little more than a nub which is what gives them their name. The word colobus actually means "mutilated one." The male is 20 to 27 inches long with a tail length of 26 to 34.5 inches and the female is 18 to 25 inches long plus a tail that is 18 to 25 inches (Colobus Monkey, Zoological Society 1996).

There is not a designated time of the year for breeding. There is a five month gestation period before the child is born and reproduction usually takes place every 20 months (Species Data Sheet 1998: 2). Females reach maturity at between three and four years, while males reach it at between four and six years (Colobus Monkey, Zoological Society 1996).

Locomotion

Their legs are long and the muscles are well developed because their legs are very important in the way they move around (Species Data Sheet 1998: 2). Their legs are usually longer than their arms and are used for leaping from branch to branch and tree to tree. It is often called "acrobatic leaping" (Jurmain 1998: 162). Since they are arboreal this comes in handy. Although they do live in trees, they are not real brachiators but may be called semi brachiators (Jurmain 1998: 162). When jumping around in the trees they must be able to judge distances well and their well developed binocular vision helps them to do this (Colobus Monkey, Phoenix Zoo 1996). They do not have a prehensile tail but it may be used for balance (Colobus Monkey, Phoenix Zoo 1996). The Colobus also has callouses on his behind which helps him to sit on rough branches for extended periods of time (Species Data Sheet 1998).

Diet

The Colobus eat mainly leaves, especially those of the Celtis durandii which is a

hackberry tree (AZA 1998: 1). Three types of trees make up 69% of all they eat and these trees are deciduous and found at the edge of the forest (AZA 1998: 1). It seems these leaves have the chemical tannin in them which is probably important to their digestive processes (AZA 1998: 1). The Colobus has "cross ridged molars" which is particularly useful for grinding down leaves (Colobus Monkey, Phoenix Zoo 1996). They also eat a few other types of food which include: fruit, seeds, flowers, buds, shoots and twigs. They have also been known to eat soil, termite clay, dead wood and lichens (Colobus Monkey, Zoological Society 1996). They get what water they need from the foods they eat and from dew that collects on their fur.

Colobus Monkeys are very unique when it comes to the size and function of their stomachs. Their stomach has four compartments or chambers which are the proximal presaccus and saccus and the distal tubus gastricus and pars pylorica. The first two combine to become a fermenting section. This chamber contains fermenting bacteria. "Microbial fermentation" occurs before digestion and absorption take place. Foods are completely broken down before the digestive process occurs. Maintaining the proper pH level is of utmost importance when it comes to their digestive processes. The proximal section of their stomach has a pH of 5.5 to 7 and the distal sections have a pH of around 3. This influences what they eat, for if they do not keep proper pH levels, acidosis can occur, which can prove to be fatal. Too much fruit can cause the pH levels to drop and mess up normal digestion processes and too many high fiber foods can cause acidosis. The digestive system of the Colobus has been likened to that of cattle whose saliva plays a major role in the fermenting processes of its digestive system. Colobine saliva probably plays a major role in the function of its digestive system but not much research has been done yet. (Lambert 1998: 11)

Expected Behavior

The Colobus are diurnal and spend most of their time high up in the trees but they will feed in the lower levels. In the morning hours they will sunbathe and later in the day they will feed (Rowe 1998: 170). In my research I have come across some conflicting information. According to Noel Rowe, "social behavior is uncommon between individuals except mother and infant" (1998: 171). However, the AZA claims them to be "highly social," that individuals in the group handle the infants which creates "cohesiveness" (1998: 2). Rowe also says the newborns are handled by others. All females in the group take care of the babies, even younger females, which prepares them for the future when they have their own children (Chargot 1998: 2).

Stress is a factor in their community and ulcers are not uncommon, especially when the adult male leaves the group or is killed. Males have to leave the group when they reach maturity and they search for another group and try to replace the dominant male. (Chargot 1998: 2).

The Colobus do communicate both visually and vocally. Vocally, they have calls "for identifying their territory, warning and mating" (Colobus Monkey, Zoological Society 1996). When two groups meet they display both visually and vocally and in the evening and at dawn adult males roar loudly which helps keep distances between different groups

(Species Data Sheet 1998: 1-2). Males will also jump around in the trees as a display while roaring (AZA 1998: 2). Females are often involved in allogrooming (AZA 1998: 2).

One observer noticed that the colobus seemed to be pretty flirty when it comes to reproduction. The females seem to be very competitive and "practically threw themselves at the male's feet" (Colobus Antics 1996). It seems the females want to be chosen to be mated with and will chase the male and be chased, as well as try to impress others all day long (Colobus Antics 1996). They do engage in what has been called "multiple-mount matings" (Rowe 1998: 171).

The Chimpanzee will often hunt, kill and eat the Red Colobus Monkey. Predators of the Black and White Colobus Monkey are not usually chimps, but are the crowned hawk eagle and humans (Colobus 1998). The Colobus will not usually run from their predators but will try and do their best to hide (Black and White Colobus Monkey 1998).

Conservation

The Colobus Guereza is not considered an endangered species, however, some populations around the world are declining in numbers. This is due to the fact that humans are using their land for development which practically forces them out. Near the Indian Coast in Kenya, deforestation has taken place and monkeys were getting hit by cars, so ropes were strung across the roads from tree to tree which enables them to cross safely (Chargot 1998: 2). The Colobus have also been hunted for their pelts which are used both locally and overseas for decoration and wear (AZA 1998: 4). As was said earlier, baby Colobus are completely white, which is quite beautiful and unique. According to an employee at Jungle Larry's Carribean Gardens, babies are sought after and sold for this reason. But what happens once their coloring changes?

The Colobus are included in the "Old World Monkey Taxon Advisory Group of the AZA" and the WCMC has approved a Species Survival Plan (AZA 1998: 2). Managing them before populations decline to seriously low levels is very important in the survival of this species. Space is becoming more and more limited. There is a Colobus Guereza studbook which keeps track of more then 1200 of this species and shows that slowly the population is growing (AZA 1998: 2). Important to this Species Survival plan are zoos and national parks and forests both within the United States, Africa and in other countries.

Jungle Larry's Carribean Gardens

Demographics

Number: 2

Sex: both male

Ages: both 12 years old

Dates of birth: 7/13/86 and 9/23/86

Acquisition date and location acquired from: 6/23/98 from Cheyenne Mt. Zoo, Co.

Breeding/fertility: Neither are breeding at this time because the are both male and there is no female to mate with, but they are both fertile and capable of helping to create life.

Relationships: They are half brothers.

Social Grouping

The two males form this social group. They often mount each other. One does not seem to be more dominant than the other, according to two of the park employees.

Locomotion

These Colobus are not unlike those found in nature. They enjoy spending their time in the tree tops and move around by leaping and jumping. One of the employees noticed that their tails seemed to be of some use to them when leaping, possibly as some sort of way to steer.

Park Diet

It seems the Colobus at Jungle Larry's each have their own favorite foods. One likes potatoes and the other likes grapes. Other foods include corn on the cob, peppers, tomatoes, banana peels, romaine lettuce and cabbage.

Observed Behavior

I got my first glimpse of the Colobus while standing on Flowering Tree Island at Jungle Larry's. I knew from research that they would most likely be in the tree tops and difficult to see, so I focused my binoculars up high. All of a sudden I saw a quick flash of black fur hurrying around one side of a tree, and then it was gone. It seemed to be moving very fast and to be adept at tree living. Fortunately, when we went by their island on the boat ride, the park employees were just about to feed them. At first they were high up in the trees and I only saw one, but they knew what time it was and they sped down through the limbs. Their goal was getting down so they did more swinging and grasping than leaping with their hind legs. It was a breezy day and they wind made their fur seemed to be flowing. They actually looked quite beautiful. The two monkeys did not interact with one another while they were eating, they had their own meals and brought the food to separate perches. It seems to be true that they eat on the lower levels of trees because they did not bring their food up higher in the tree, but maybe they were really hungry. I did not get a chance to see what it was they were eating, but they were very involved in it. As our boat drifted away, they were still munching heartily.





References

AZA-Colobus Monkey Species Survival Plan. 1998. 22 November1998.

Black and White Colobus Monkey. 22 November 1998.

Chargot, Patricia. The Colobus. 22 November 1998.

Colobus. 22 November 1998.

Colobus Antics. 1996. 21 November 1998.

Colobus Monkey. Phoenix Zoo. 1996. 17 October 1998.

Colobus Monkey. Zoological Society of Philadelphia. 1996. 17 October 1998.

Jurmain, Robert, Harry Nelson, Lynn Kilgore, Wenda Trevathan. Essentials of Physical Anthropology. 3rd ed. Belmont: Wadsworth Publishing Co., 1998. 161-162.

Lambert, Joanna E. "Primate Digestion: Interactions Among Anatomy, Physiology, and Feeding Ecology." Evolutionary Anthropology. Ed. John G. Fleagle. New York: Wiley Liss, Inc., 1998. Vol. 7, Issue 1. 8-20.

Rowe, Noel. The Pictorial Guide to the Living Primates. East Hampton: Pogonias Press, 1998. 170-171.

Species Data Sheet. 17 November 1998.