Scientists have captured video images of a wild pygmy hippopotamus (Choeropsis liberiensis), a rare and elusive nocturnal species that has rarely been observed in its natural habitat in Liberia.

Western scientists and zookeepers have been aware of the pygmy hippopotamus for more than a century, and the species breeds well in captivity, but very little is known about its behavior in its native forest habitats.

The brief video, which you can see below, shows just a few fleeting seconds of a pygmy hippo as it slips between the underbrush in Liberia's Sapo National Park. The video was shot using camera traps set by the Forestry Development Authority of Liberia, Fauna and Flora International, and the Zoological Society of London (ZSL).

At 180 to 275 kilograms, pygmy hippos are less than one sixth the weight and size of the common hippopotamus (Hippopotamus amphibius), their only living relatives. All other hippo species went extinct hundreds if not thousands of years ago. The pygmies are found in Liberia and in tiny "pocket" populations in Guinea, Ivory Coast and Sierra Leone.

The International Union for Conservation of Nature and Natural Resources (IUCN) puts the wild pygmy hippo population at around 3,000, although that number is based on guesses from research conducted nearly 20 years ago. According to the ZSL's pygmy hippo conservation web page, "the numbers have likely declined as its forest habitat has become extremely fragmented and is under increasing pressure from logging, mining and farming. As a result, this has brought pygmy hippos into closer contact with humans and increased the risk of hunting and conflict." The animals are hunted both for subsistence and to supply the growing bushmeat trade that threatens so many other species in Africa. Both the ZSL and the IUCN indicate that a second pygmy hippo subspecies which used to live in Nigeria but has not been seen in more than 50 years is likely extinct.

According to the IUCN, 303 pygmy hippos were living in 135 zoos around the world in 2004. Almost all of them were born in captivity and descended from a founder population of just 70 animals.

The ZSL is accepting donations to help fund its efforts to conserve the pygmy hippo in the wild. Money will go to help buy things like Wellington rubber boots and tents for community research assistants as well as additional camera traps. If the first video didn't whet your appetite for pygmy hippos, check out this footage of a baby hippo born at Australia's Taronga Zoo in 2008:

Photo: screen grab from Zoological Society of London video