Kenya Wildlife Service veterinary doctors are conducting a post-mortem examination to establish what caused the death of one of the rarest pygmy hippos at the Nairobi Safari Walk.
The secretive hippo named Elizabeth, was one of the two donated to Kenya Wildlife Service in the 70s by the former Liberian president William Tubman, died on Monday night under mysterious circumstances.
KWS Corporate Communications Manager Paul Udoto said they could not immediately tell the cause of death because it is "a secretive and shy animal although the survival of the species in captivity is more assured than in the wild".
In 2004, when KWS was renovating the Safari Walk, the animal was relocated to the Mount Kenya Game Ranch where it is said to have given birth to several offspring.
The pygmy hippo, according to KWS differs from its ordinary Nile cousin which is indigenous to East Africa because it is very short and lives isolated mostly in West African countries like Cote d'Ivoire, Liberia, Sierra Leone, Nigeria and Guinea.
The smaller hippo has adaptations for living in the water but normally prefers living deep in the forests.
The World Conservation Union (IUCN) says pygmy hippos are severely threatened by the continual deforestation and poaching with an estimated 3,000 individuals remaining in the world.
As a protection measure, they were introduced to zoos in the early 20th century and have breed well in captivity and the vast majority of research is derived from zoo specimen.
Pygmy hippos are primarily threatened by loss of habitat, as forests are logged and converted to farm land, and are also vulnerable to poaching for meat and natural predators.