Hippos from the Turgwe Reserve

 

Hippo Fact Sheet

The African Hippo Population: about 157, 000 (a quarter of the elephant population)

Hippo Population in the South East Lowveld of Zimbabwe: 2000 pre-1991/92 drought, now approximately 350 animals.

Longevity: 40-45 years 

Gestation Period: 8 to 8 1/2 months

Weight of New Born Calf: 20 kg Mature female: 1 1/2 tons Mature male: 2 - 3 tons

Food: mainly grass, eating up to 45 kg per night 

Drink: up to 250 litres (56 gallons) in any 24 hours

Speed: up to 30 mph (40-45 km/hr) 

Maximum Time Under Water: up to 5 minutes for an adult 

Where It Lives: Formerly anywhere south of the Sahara where adequate water and grazing occured. Confined now to protected areas, but still survives in many rivers and swamps.

Activity: During daylight hours, spend most of their time in water, socialising and digesting the previous night’s fodder. During cooler months, they like to lie up on sandbanks in the sun. At night they leave their water habitat, travelling up to 2 or 3 miles (3 to 5 km), at most normally 6 miles (10 km) for their nightly foraging.

Offspring and Maternal Care: Cows isolate themselves before calving, giving birth on land in weeded areas close to water, or sometimes in the water. They stay alone with the tiny baby for 8 to 21 days so that the calf can imprint with its mother, then they rejoin the group. Calves nurse under water, automatically resurfacing to breathe. At first they can only submerge for approximately 35 seconds; this increases up to 2 minutes by two months of age. They start to nibble at grass by about five months and here in the Turgwe are not weaned until 20 to 22 months. Calves can be left in ‘creches’ while mothers go off to graze in the evening, where they are guarded by one or sometimes a couple of cows. 

Territorial Advertising: This is done mainly by the bull. It is achieved by backing up to an object such as a bush or a rock, and simultaneously urinating and defecating by paddling excrement with its tail. This can be done in or out of the water. Bulls tend to do this frequently but cows have been observed doing it as well. This marking defines the extension of the bull’s territory, as well as indicating to other members of the group the direction the bull has taken on his evening forages. 

Calls: The normal call of a hippo is classified as wheeze honking; it sounds more like a laugh with a loud ‘humph humph humph.’ One hippo calls and normally all the others respond. The calling occurs most frequently in the early morning as the hippos re-enter the water and at sunset before leaving the water. They also have various grunts and wheeze type noises, with the female emitting a loud purring like call when being mated or when wanting to be mated. At night it is mainly the bulls that call and not as frequently as in the water. 

Gaping: Hippos have a wide variety of reasons for gaping. One is a genuine yawn where the jaws are opened widely, often with the hippo male or female stretching up with its head out of the water. It is as well a standard threat display, exposing the obviously large lower canines (In a male, the lower canines have been known to grow to 3 feet in length). Gaping is often used in play between calves or between calves and adults, where the gape is followed by a pushing jostling competition.

Threat Display: Water scooping, where a hippo appears to be mouthing and gulping the water, usually with tightened or staring eyes. Snorting, mock charging or full blown charges which can be followed up by actually leaving the water. Head shaking and chasing other hippos. Exhaling explosively above or below the water surface.

Their Response to Predators: Diving and swimming away under water. This can be a reaction to people or vehicles where hippos have been subjected to shooting. Aggressive response by gaping, water scooping, head shaking or charging.

Future of the Hippos within Africa: On appendix II of CITES due to poaching in many western and central African countries. Poachers provide hippo teeth for use as a substitute to elephant ivory for the carving of curios for the tourist market. The habitat is slowly shrinking in many parts of Africa due to ever increasing human population.