Hippos live in and along rivers in sub-Saharan Africa. During the day, they retreat to the water to rest, socialize and avoid the heat; at night, they feed in grassy areas adjacent to rivers. They are herbivores, primarily eating grass.
In Greek, hippo means horse; potamus means "of the river." Hippos are said to sweat blood because their skin exudes a thick, red oil that protects them from sunburn.
Hippo behavior and facts
- Hippo skin is brown to gray-purple with pink undersides. Fine hair covers its body. Hippos must have access to water or their skin dries out and cracks.
- Their senses of hearing, sight and smell are excellent. Its ears, eyes and nostrils are atop its head so the hippo can be submerged (which helps controls its body temperature) while still aware of its surroundings.
- At night, hippos graze on grass for up to 6 hours; areas along rivers where they clip the grass short are called "hippo lawns."
- They can stay underwater between 3 and 5 minutes.
- Adult males compete for territories and the groups of females and young in them. Sometimes confrontations are to the death.
- Hippos are considered one of the most aggressive animals on earth, at times attacking without provocation. They can outrun a human over short distances.
From birth to death
- Hippos mate during the dry season.
- Females give birth to one 55- to 120-pound baby in shallow water or underwater.
- Babies nurse underwater up to 18 months.
- Hippo mothers are protective; babies lie across their backs in deep water.
- Hippo babies can swim before they can walk.
- Sexual maturity: females 7- 9 years; males 9 to 11 years
- Lifespan: 35 to 45 years
- Height: 4.5 feet
- Weight: 3,000 to 7,000 pounds
- Length: 11 feet
CITES Appendix II due to poaching for meat, fat, hide and ivory, and human encroachment. Hippos are common in captivity and breed readily. Many captive females are on birth control.
Hippos, the Oregon Zoo and you
The zoo's hippos live in the Africa Savanna exhibit. Each hippos daily diet consists of 30 pounds of Timothy hay and one and a half gallons of grain. They also receive enrichment treats of apples, carrots and lettuce.
Hippos are vulnerable to meat and ivory poaching and loss of habitat as increasing human populations put pressure on the waterways hippos depend on.