How Big Is a Pygmy Hippo? Size Compared to Common Hippos

Pygmy hippo size at a glance

The pygmy hippopotamus (Choeropsis liberiensis) is the smaller of the two living hippo species. It has the same barrel-shaped body and short legs as its relative, but everything is scaled down for life in dense West African rainforest.

All figures are typical ranges for adults; individual animals, especially well-fed zoo animals, can fall slightly outside them.

How does a pygmy hippo compare with a common hippo?

The difference in weight is much bigger than the difference in height. A pygmy hippo is about half as tall as a common hippopotamus, but because weight increases with length, height and width together, it ends up with only a small fraction of the body mass. An average common hippo of about 1,300–1,500 kg (2,900–3,300 lb) weighs roughly six to eight times as much as an adult pygmy hippo. A big common hippo bull of 2,500 kg (5,500 lb) or more weighs about ten times as much.

To picture it, a pygmy hippo is about the size of a large domestic pig, while a common hippo bull is about as heavy as a small car. For more detail on the larger species, see How much does a hippo weigh?

Different body shape, not just a smaller size

A pygmy hippo is not simply a miniature copy of its relative. Its body is built for squeezing through forest undergrowth rather than for floating in open rivers:

• Sloping back. The common hippo’s back is roughly level, while the pygmy hippo’s back slopes forward, which helps it push through thick vegetation.
• Longer legs and neck, smaller head. In proportion to its body, the pygmy hippo has relatively longer legs and neck and a smaller, rounder head.
• Lower-set eyes and nostrils. A common hippo’s eyes and nostrils sit high on the head so it can see and breathe while almost fully submerged. In the pygmy hippo they stick out much less, reflecting less time spent in deep water.
• Slimmer bones. Its skeleton is lighter and more slender for its size.
• Spread toes. The four toes on each foot are more spread out and less webbed, which helps on soft, muddy forest ground.

These differences are why scientists place the pygmy hippo in its own genus, Choeropsis, separate from the common hippo’s genus, Hippopotamus.

How big are pygmy hippo calves?

Pygmy hippo calves are tiny at birth. After a pregnancy of about 190–210 days, a single calf is born weighing about 4.5–6.2 kg (10–14 lb), roughly the weight of a house cat. That is around one-fortieth of its mother’s weight. A newborn common hippo, by comparison, weighs about 25–55 kg (55–120 lb).

Calves can swim almost at once. In the first months they hide in water or dense cover while the mother feeds, and she returns several times a day to nurse them. They are weaned at about six to eight months and reach sexual maturity at roughly three to five years old, by which time they are close to adult size. The famous zoo calf Moo Deng, born in Thailand in July 2024, became an internet star while still at this small, bouncy stage.

Why are pygmy hippos so small?

The small size of the pygmy hippo seems to suit its forest home. In dense rainforest, a large body would make it harder to move along narrow trails, hide in small streams and swampy hollows, and find enough food. Grass, the main food of common hippos, is scarce under the forest canopy, so pygmy hippos browse on ferns, broad-leaved plants, shoots and fallen fruit instead. A smaller body needs less food overall.

Fossils suggest that early members of the hippo family were also fairly small, so the pygmy hippo probably did not “shrink” from a giant ancestor. Its lineage and the common hippo’s may have separated as long as 8 million years ago.

Pygmy hippos vs dwarf hippos

The pygmy hippo is sometimes confused with the extinct dwarf hippos that lived on Mediterranean islands such as Cyprus, Crete, Malta and Sicily. Those island hippos were similar in size, but they evolved from larger mainland hippos that became smaller over many generations on islands, a process called insular dwarfism. They died out thousands of years ago and are not close relatives of the living pygmy hippo.

Today the pygmy hippo survives only in the forests of West Africa, mainly Liberia, as described in Where do pygmy hippos live? It is listed as Endangered by the IUCN, with fewer than 2,500 mature animals estimated to remain in the wild.