Little is known about the private life of the pygmy hippo except that it spends its days hiding in the swampy shallows of rivers, only to emerge in the dead of night to forage furtively on the forest floor.
Fewer than 3000 are thought to have survived the extensive destruction of the west African habitat where it lives and its rarity has placed it in the list of endangered species. Now, a British zoologist has taken some of the first pictures of pygmy hippos in the wild with the help of a network of automatic camera traps.
Capturing images of the retiring animals in Liberia is even more remarkable, given that the region has had two civil wars and an epidemic of brutal poaching for bushmeat in remote forests where well-armed miners pan illegally for gold.
Ben Collen, a research fellow at the Zoological Society of London, took the shots with the help of a team of locals who set up 32 camera traps spaced 2km apart over a network covering a sizeable part of the Sapo National Park where many of the remaining pygmy hippos live.
To his surprise, the animals were photographed within three days of the camera traps being set. "We knew we'd get something or other, but I never dared hope that we'd get pygmy hippos so soon," Dr Collen said.
"The pygmy hippo is an extraordinary, mysterious creature that has almost never been seen in the wild ... we were delighted to discover that a population still persists there, but remain highly concerned for the species, which continues to face significant threats from poaching and habitat degradation."
The pygmy hippo grows to about half the height of its full-sized cousin and leads a solitary life, feeding on ferns, leaves, fruits and indeed anything it can find on the forest floor. Its vastly reduced habitat extends into four countries: Liberia, Sierra Leone, Guinea and Ivory Coast. Three other species of pygmy hippo that lived on Madagascar have become extinct in modern times, as has a subspecies that lived in Nigeria.
Unlike prehistoric dwarf hippos that lived on the Mediterranean islands of Sicily, Malta and Crete, the pygmy species are not descended from a larger species that became smaller as a result of living on an island.
Dr Collen said it was important to confirm the presence of pygmy hippos in the Sapo National Park because it would help attempts to assess their numbers and maintain a viable breeding population.
The zoological society has identified pygmy hippos as one of the key species in its Edge animal-conservation programme that are in need of urgent attention if the species is to survive.
John Woods, managing director of the Forestry Development Authority in Liberia, which helped to organise the camera-trap project, was surprised to discover the pygmy hippo alive and well.
"I was pessimistic about [its] existence ... at Sapo." - INDEPENDENT