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Hippopotamus range: African countries of Sub-Saharan Africa read more >


Scientific name: Hippopotamus amphibius

CLASS: Mammalia
ORDER: Cetartiodactyla
FAMILY: Hippopotamidae

STATISTICS: Weight: 5000 – 8000 lbs Height: 5 – 5.5 ft Length: 9.5 – 14 ft

The hippopotamus is almost hairless with extremely thick skin. The skin has glands that secrete droplets of a red pigmented oil-like substance that works as a skin moistener and sunblock. This gave rise to the belief that it sweats blood.

Its eyes are protruding, it has slit-like nostrils, and the ears are set high on the back of its head. The hippopotamus has razor sharp incisors and tusk-like canines, and it can open its jaw to a 150 degree angle.
The males are typically larger than the females. The usual color of the skin is copper brown, along with shades of dark brown on the top as well as dark purples below. It has a barrel-shaped body, with a large head and a short neck.

African countries of Sub-Saharan Africa

African rivers, lakes and grasslands

Hippos can live either as solitary animals or in groups of a few to over a hundred called schools. These schools can have any number of males, females, or calves. Often there is one overly territorial bull that is dominant. It is the only male in the group who will reproduce. Bulls are very aggressive and will fight for dominance using their large tusks to jab into the other’s sides and rump. Also it will loudly bellow, or scoop up water into its mouth and spray it high into the air. These fights often leave scars on the hippopotamus and can even be fatal. Aggression can also occur in females, especially those with young. It may be aggressive particularly towards humans, and is often said to be the most dangerous animal in Africa.

A hippopotamus spends most of its time in the water in order to keep cool in the hot sun. It is heavy enough that its weight can pull it down to the bottom of a lake, river, or stream to where it can actually walk on the bottom. It will spend most of the day sleeping in or near the water, and will come on land at night to graze. It can stay underwater for about three to five minutes. When it submerges itself underwater, it closes its nostrils and ears along with its eyes. Due to the placement of the eyes and nostrils, a hippopotamus can be almost completely submerged and still be able to see and breathe. Hippos will travel up to six miles to graze, and will consume about 80 lbs of grass a night. However, its metabolic rate is very slow so it can live several days without eating. These adaptations help the hippo in its survival, since most animals will not dare to prey on an adult hippo.


Breeding occurs seasonally, typically during February or April, and occurs in the water. After a gestation period of about seven and a half to eight months, a baby hippopotamus is born. Typically only a single calf is born, but there have been cases of twins. Birth usually takes place on land or in shallow waters. At birth, the calf can weigh 55 –121 lbs, and can weigh up to 550 lbs by the end of its first year. The young calves can swim before they learn to walk, and they can nurse underwater. A calf can also climb up on its mother’s back while she is floating on the surface and sun itself. Such behavior has been thought to be used as protection from crocodiles, but it is likely to keep the calf from having to struggle to stay afloat. Mothers are very protective of their young and always defend them if there is danger. The calves depend upon the cow for several months after birth.. Sexual maturity is reached when the males are about 6-13 years of age and the females are about 7-15 years of age. Upon reaching puberty, a male may be driven away from the group by the dominant bull.

Prey to man
Predator to none

Grasses and water plants

Listed as Vulnerable by IUCN and CITIES appendix II due to habitat loss and poaching for its ivory canines, its hide, and its meat.


  • The Greeks called the hippopotamus the “river horse” because of its love of water.


  1. Nowak, Ronald M. Walker’s Mammals of the World. Vol. II. Pg 1348-1350. Baltimore, Maryland. The Johns Hopkins University Press. 1991
  2. IUCN Red List of Threatened Species. 2008.
  3. National Geographic. Book of Mammals. Vol. I. Pg 259-263
  4. Grzimek’s Encyclopedia. Mammals. Vol. V. pg 58-79
  5. National Geographic. Hippopotamus. 2009.

Published: August 2010

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