(Theropithecus gelada)

Amharic: Gelada

The Semyen highland massif is considered to be the finest scenery in all Africa and it is for this reason, and the fact that the area is the home of the Walia Ibex, the Semien Fox and the Gelada Baboon that it has now been gazetted as a national park.

The Gelada is not in fact peculiar to the Semyen as is the exclusive Walia Ibex, but they are more numerous here than in their other habitats Some live at Debre Sina not far from Addis Ababa and others at Debre Libanos on the way to the Blue Nile; there are also small populations in the Mulu and Bole Valley gorges. But in the Semyen there may be as many as 20,000, and troops of 400 together may be seen. They do not molest humans and, more surprisingly, the local people do not molest them. Thus they are very tame and will allow humans to approach quite close to the troop before moving nearer to the cliff edge.

The Gelada was discovered in 1835 by the explorer Ruppell, who nan;ed it by the local name used by the inhabitants of Gonder region where he first observed it. They are not difficult to study as they are very tame, however, little interest was shown in them until recently, when Patsy and Robin Dunbar made an exhaustive study of their social behaviour. The social behaviour of the apes and monkeys is evidence of a very high degree of intelligence and studies of their rudimentary social structures are proving of considerable value in analysing the origins of human social behaviour.

Geladas live along the edges and steep slopes of precipices. They never move far from the rim and thus their distribution is linear along the escarpment. At night they climb down the steep cliff faces to caves where they roost on ledges, often huddled close together for warmth as Semyen nights are frosty and bitterly cold. Babies cling tight to their mothers even in sleep. In the morning in the warm sun they climb up again to the top of the cliff and spread out to feed. Geladas are mainly vegetarian, living on herbs, grasses and roots, but they also eat insects and locusts. They never eat meat, or hunt or kill even small birds or mammals. As a result of this restricted diet they are obliged to spend a very high percentage of their lives foraging and browsing in order to obtain sufficient nutrients to survive. This may explain why they are so extremely peaceable by nature, with very little squabbling even amongst themselves. They have no natural enemies (except of course, Man, who takes a fair toll with his rifle. The great mane of the adult male is used for traditional headresses by highland warriors).

Apart from feeding, "grooming" is their other main pastime. This entails simply picking through each other's fur. This is not only a friendly and peaceful occupation, but it serves also to establish bonds between various members of a 'harem' and to cement the accepted relationships in the hierachy, between male and female, older and younger members.

The long narrow plateaus of the Semyen slope up- wards from the south until they end in the dizzying precipices of the northern escarpment. This is the haunt of the Walia, and the Gelada do not frequent these vertical cliffs, but the rims of the stupendous gorges and ravines which bisect the plateau. The troops tend to graze the higher moorlands, amongst everlastings, giant lobelias and alchemilla-tussock grass. Never far from the rim, which is their refuge when danger threatens, they disappear over the edge on to the grassy slopes and ledges of the gorge sides. Their grazing ranks are so arranged that the males are always farthest from the edge and thus it is "women and children first" when they have occasion to flee to safety.

They are comparatively large and impressive, the males being about 75 cms. (30 inches) tall without tail and twice the size of the females. Their sad up- turned faces are marked with large ridges running from below the outer side of the eyes to the nose. The face is dark grey with wrinkles and very long whiskers, forming falciform tufts of light coloured hairs projecting upwards and backwards on the sides of the head. Their nickname, "bleeding heart baboon" stems from the bare red skin areas on the chest, which are actual]y two triangles, and another crescent-shaped on the throat. Both sexes have these bare places. In the female the fleshy "beads" which surround the bare patch swell up and turn from whitish to bright red to indicate estrous condition. In the males the patches are always red and do not change colour. The old males have a cape of very long hair which hangs down (to the ground when they are sitting) and tufted tails which have earned them another name - lion monkey. The female's mane is much less impressive than the male's. Both sexes are a light to dark brown, the fur cape shading from one colour to another as it moves in the mountain breezes. They are found at more than 4,500 metres (14,600 ft.) and have even been seen at the top of Ras Dashan at 4,620 metres (15,160 ft.) where tbere is nothing fox them to eat, so they must just go up to look at the view.

Their handsome appearance and the beauty of their habitat is one thing, but perhaps the most fascinating aspect of these creatures is their social structure which is the most complex in the animal kingdom after that of man. You see them grouped into herds of up to 400 or so individuals, each of which is made up in turn of "harems", which are groups of from two to eight females and young ones with one dominant male and often one hanger-on called a "follower", who ingratiates himself with the juvenile females, with a view to enticing them away in due course and forming his own harem. Harem owning males do not attempt to steal each others' wives.

Young males get together in groups from the age when they finally leave their mothers until they are mature enough to become a follower. These various social groups all move and feed together, only occasionally leaving the herd if food supplies demand it. They travel about three miles a day while feeding, and sleep on ledges on the cliff face wherever they happen to be when night falls.

The harem is a very close family unit. Ninety-five percent of the social interactions of adults are with other members of the same harem. Only juveniles and babies cross the invisible boundaries to play with others of their own age. Unlike the Hamadryas baboon, where the harem is kept together by male agression, the Gelada harem is run more or less by solidarity between the females. It is they who decide in which direction they will feed, it is they who instantly rally together if their male should threaten any one of them because she strayed too near another male! Only one of the females has a strong relation- ship with the male at any given time. But they all groom each other as well as him and thus establish a jealousy-free harmonious relationship with each other.

For a young male to acquire a harem of his own is quite a long and difficult process. He starts off when he is about two leaving his mother's harem in favour of play groups of other juveniles. By the age of three he starts playing around with the younger members of the all-male groups, and at four he things of nothing else but joining one (which is not always easy as the groups are very tight and do not readily welcome new members). Having succeeded he settles down to life as a bachelor sub-adult in his group. When he is about five or six, he begins to show an interest in the harems again. He doesn't want to anger the adult male of any harem so he confines his activities to following along, occasionally grooming with the male but mainly amusing himself with the young females - the ones too young to cause jealous feelings in the old male. Should the old male die or become weak, the young one will take his place, but it is more common for the youngster just to gradually withdraw taking with him several of the young females. This is not a sudden break - the one group just spends progressively more time on its own. The male then sets about getting a few more females from other harems - young females belonging to a harem with no follower may join him before their father takes an interest in them.

Over the years each male has a succession of followers who take away his daughters to form the nucleus of their own harems; a system which prevents in- breeding. Sometimes a younger male may persist in paying court to the wives of an older, and generally harrass him. The few fights which occur are usually the outcome of such behaviour. The old one finally, after trying to retain his females' loyalty and affection, may give up the struggle. If so, he does not retire from the harem - he just adopts the follower role and spends his retirement grooming and playing with the juveniles.

The relationships of the Geladas are very delicately balanced. To communicate their intentions they have need of a fairly subtle range of signals. They have therefore acquired a great diversity of social behaviour patterns and vocalizations. Greater in fact than any other non-human primate. For examp]e, where the olive baboon has fifteen contact calls, and the colobus six, the gelada makes twenty-seven distinct noises. To hear him speak, is as it were to listen to a foreign language being spoken. The expressions on the face are in fact signals with a distinct meaning: the raising of the eyebrows reveals two red triangles above the eyes - a warning signal; the rolling back of the upper lip in a ghastly smile, a flash of red gums and white teeth, signifies (as perhaps does the human smile) appeasement, and thus avoids possible conflict.

So far, the gelada is not on the endangered species list, and now that he lives protected in at least one of his habitats, one can hope that he never will be. How- ever, the occasional random slaughter "for fun" of these beautiful, gentle and intelligent creatures should be curbed for obvious reasons.