Distribution:  Originally from Nile Delta to Cape up to 6,500 feet, where adequate water and grazing was found.  Present distribution is shrinking rapidly. 

Habitat:  Swamps, lakes and rivers are used as daytime refuges.  Larger groups favor firm, sloping beaches and quiet waters where they can stand on bottom close to surface.  Closely cropped lawns, paths leading from water and accumulations of dung are signs of intensive use by hippos.  Aggregate at permanent water sources during dry season and disperse widely during rains.

Food and Feeding Methods:  Creeping and tussock grasses are grazed at night.  Crops grass by means of leathery ‘lawn-mowing’ lips.  Walks slowly, closing lips over mouthful of grass and wrenching it away with regular swings of head.  Can eat up to 135 lbs. of grass in a night’s grazing and rarely needs more than 5 hours out of water.  Slow but efficient digestive system and a modest appetite for its vast size.

Social Behavior:  Socially schizophrenic: silent, solitary grazer on land by night and vocal, densely social and sedentary wallower by day.  Tolerate close contact in water but are highly aggressive and unsocial when foraging on land where herding for safety from predators is unnecessary.    Herds in water can range from 2 to 50, but typically number 10 to 15.  Crowding and aggression is greatest during dry season.  

Females accompanied by up to 4 successive offspring are only stable social unit.  Mature bulls over 20 years control narrow strips of water and shoreline as exclusive mating territories, but will tolerate bachelor herds within domain and in cow herds as long as they are subordinate, acting submissively and refraining from mating.  Often bachelor herds live apart from females in least favorable habitats and territorial males chase rivals away with great ferocity.  There are no close ties between cows in a herd except for maternal bond between mothers and daughters that lasts to subadult stage. Changes in grouping patterns and density, and territorial turnovers can occur quite often due to climatic and environmental changes. 

Hierarchical society in which individuals must advertise their status and condition, especially to superiors.  Voiding urine or dung and prostration before a dominant individual are normal forms of appeasement.  Territorial bulls show dominance through wide yawning and dung-showering, where they lift their tails and use as paddles to shower dung and urine.  Large groups are very vocal in water.  The main call, a loud nasal wheeze followed by a series of guttural honks, is uttered in response to all disturbances, particularly in evening when hippos begin to move. 

Reproduction:  One, rarely 2, young are born after 8-month gestation, peaking during rains.  Mother segregates herself and baby for up to 2 weeks and is highly alert and aggressive.  Bond between mother and calf is close.  Calf begins to graze at 1 month, but will suckle up to 8 months and is specially adapted to nurse under water.  Continue to grow for 5 to 6 years.  Females sexually mature between 7 and 15 years; males mature sooner but are kept from breeding until older by dominant males.  Can live up to 50 years in captivity.

Status:  Has been eliminated over much of its former range, especially in populated areas.

Adaptations:  Hide is peppered with glands that exude a blood-like fluid that forms a flexible varnish and acts as antiseptic for wounds, sunscreen, water-loss sealant and social perfume.  Skin is well adapted to constant immersion in water but also makes hippo vulnerable to dehydration; they can’t survive long away from water and only graze at night or in rain.

Can stay under water for 5 minutes, surfacing to breathe even in their sleep.  Swimming hippos effectively gallop underwater and can walk on bottom when submerged.  Look clumsy on land but can run up to 19 mph and have killed more people than any other animal in Africa.

Head/Body Length:    9 - 11 ½ ft.                                            Tail Length:    1 - 1 ½ ft.
Shoulder Height:        4 - 5 ¼   ft.    
Weight:                 3,535 - 7,075 lbs. (male)   1,125 - 5,525 lbs. (female)

The Hippopotamus and the Tortoise

Many years ago the hippopotamus, whose name was Isantim, was one of the biggest kings on the land; he was second only to the elephant. The hippo had seven large fat wives, of whom he was very fond. Now and then he used to give a big feast to the people, but a curious thing was that, although everyone knew the hippo, no one, except his seven wives, knew his name. At one of the feasts, just as the people were about to sit down, the hippo said, 'You have come to feed at my table, but none of you know my name. If you cannot tell my name, you shall all of you go away without your dinner.' As they could not guess his name, they had to go away and leave all the good food and tombo [palm wine] behind them. But before they left, the tortoise stood up and asked the hippopotamus what he would do if he told him his name at the next feast. So the hippo replied that he would be so ashamed of himself, that he and his whole family would leave the land, and for the future would dwell in the water.