Central Africa


Slow-moving rivers and lakes

What’s in a name?

Watch a hippo, on land or in the water, and you’ll soon discover that this roly-poly is one of the animal world’s great characters. It is the most rotund land mammal and spends its daytime hours in lakes, pools, mudholes, or in the preferred moving waters of rivers.

The name “hippopotamus” comes from a Greek word meaning “water horse” or “river horse.” But hippos are not related to horses at all—in fact, their closest living relatives may be pigs or whales and dolphins! There are two species of hippopotamus: the river, or common, hippo and the much smaller pygmy hippo.

Come on in, the water’s fine!

Hippos are definitely adapted for life in the water and are found living in slow-moving rivers and lakes in Africa. With their eyes, ears, and nostrils on the top of the head, hippos can hear, see, and breathe while most of their body is underwater. Hippos also have a set of built-in goggles: a clear membrane covers their eyes for protection while still allowing them to see when underwater. Their nostrils close, and they can hold their breath for five minutes or longer when submerged. Hippos can even sleep underwater, using a reflex that allows them to bob up, take a breath, and sink back down without waking up.

Yet despite all these adaptations for life in the water, hippos can't swim—they can't even float! Their bodies are far too dense to float, so they move around by pushing off from the bottom of the river or simply walking along the riverbed in a slow-motion gallop, lightly touching the bottom with their toes, which are slightly webbed, like aquatic ballet dancers.

When agitated, a hippo can charge at up to 14 miles per hour (30 kilometers per hour) on land.
The hippo is similar in size to the white rhinoceros.
Hippos can store two days' worth of grass in their stomachs and can go up to three weeks without eating.
An adult hippo can hold its breath underwater for up to 30 minutes.
In African rivers, hippos look like floating islands, with birds fishing from their backs.
Turtles and even baby crocodiles have been seen sunning themselves on hippos.
A group of hippos is sometimes called a bloat, pod, or siege.
Hippos have stiff whiskers above the upper lip and some fuzziness around their ears and on their tail.
Several fish species in Africa can keep busy feeding on the food remnants and dead skin cells found on the hippo’s skin.
Hippos are much faster than they appear, reaching speeds of 20 mph (32 kph) on land and also moving quickly in the water.
Hippos vocalize on both land and in the water and are the only mammals that make amphibious calls.

Our first hippos

Puddles was the San Diego Zoo’s first hippopotamus; born on July 8, 1935, at the Brookfield Zoo outside of Chicago. He arrived here in August 1936, becoming the first hippo to be exhibited by a zoo on the West Coast. He became quite the viewing sensation.

Rube and Ruby were popular from the moment they arrived in 1940 as youngsters from the Calcutta Zoo in India. The pair produced 11 offspring during their time together, with their first calf born in 1943. Hippos have an average life span of 25 to 30 years in the wild, but Rube’s 51 years made him one of the oldest hippos in zoos. Although Ruby died in 1982 and Rube in 1988, they have been immortalized as two of the Zoo’s popular costumed characters! During their time here, hippos became one of the Zoo’s most popular attractions, seen by millions of visitors.

A wonderful pool

By 1986, the 50-year-old hippo exhibit was showing its age, and a decision was made to close it until it could be replaced with an up-to-date facility. That facility became a reality when a new hippo exhibit opened in 1995. It continues to offer millions of people a safe way to get an up-close-and-personal view of hippos. Zoo visitors can observe hippo behavior on the beach and underwater all year long, as the exhibit features 110 feet (33.5 meters) of underwater viewing behind a 2¼-inch-thick (5.7 centimeters) glass window, engineered to withstand the force of a 2-ton (1.8 tonnes) hippo moving at 15 miles per hour (24 kilometers per hour). Thanks to the temperate San Diego weather, the water in the pool does not need to be heated or chilled.

The pool is serviced by a large water filtration system and is also kept clean by a school of tilapia, one of the several species of African fish that, in the wild, would normally be feeding on the hippos’ dead skin and food remnants.

Our hippos today

We currently have a pair of these impressive giants, and a hippo calf. Funani, whose name means “desire” in Zulu, weighs about 3,600 pounds (1,630 kilograms). She came to San Diego from the Knoxville Zoo in 1995, where she was known as a problem hippo. But she settled in quickly and has mellowed even further with motherhood. Since her arrival, she has had four calves.

Our adult male, Otis, is a “lightweight” for an animal that can reach a weight of 4 tons (3.6 tonnes); he tips the scale at 3,900 pounds (1,770 kilograms). He was wild born in East Africa in 1976 and brought to the San Diego Zoo from the Los Angeles Zoo in January 2009, specifically to breed with Funani. The happy result was Adhama, born on January 26, 2011. The “little” guy delighted Zoo guests with his playful antics at the viewing window and has been a YouTube sensation, showing off some ballet moves. Adhama moved to the Los Angeles Zoo in June 2013. We wish him well!

On March 23, 2015, Funani gave birth to a daughter, Devi. She has already attracted plenty of attention at the Zoo, fascinating guests at the viewing window as she explores every part of her 150,000-gallon (567,812-liter) pool—under the watchful eyes of Funani.

The river hippos in Ituri Forest will be temporarily off exhibit February 16-18, 2016, while their exhibit area undergoes some repair work.

Although hippos are not yet endangered, their habitat has been greatly reduced over the last 200 years. Once common to all of Africa, hippos are now abundant only in East Africa. Male hippos stake a claim to a stretch of river and all the females in it. It is his job to protect the group from intruders. An unsuspecting human boater who enters hippo territory risks an aggressive response. Female hippos, especially mothers with calves, can be equally dangerous and unpredictable. Sometimes, it is the hippo that invades human areas like local farmlands, devouring crops.

With the constant growth of human settlements, human and hippo territories frequently overlap, and these encounters are on the rise. Projects such as the building of dams or the diversion of water for agriculture often have disastrous impacts on natural waterways and the hippos that depend on them.

Even more devastating to hippo populations is the trade in illegal ivory. Following the 1989 ban on elephant ivory, demand for hippo ivory sharply increased. The large canines that hippos use to protect themselves are made of the same material as elephants’ tusks. In fact, they are slightly softer and easier to carve than elephant ivory, making them even more appealing. As a result, hippo numbers are rapidly decreasing. If hippos were to disappear completely, the effect on their habitat would be catastrophic. The large amount of waste hippos produce fertilizes the African ecosystem, and many species of fish eat the dung and feed on the small parasites that live on the hippos’ skin.

Elephants, cheetahs, and many other “at risk” African animals have organizations focused on their conservation, but there is no such group devoted to the future of hippos. Right now, the most promising way to protect hippos is to continue to safeguard large areas of land, as national parks offer the greatest amount of protection against poaching.