Neglected species – The plight of the pygmy hippo

The hippopotamus is surely among the most familiar – and most conspicuous – of Africa’s megafauna. Its pocket-sized relative, the lesser-known and endangered pygmy hippo, is an entirely different matter. Nocturnal, elusive and mainly solitary, these denizens of the deep forest are very rarely seen, or even heard.

Don’t be misled by the name; they may be nominally associated with miniature marmosets and small-scale shrews, but pygmy hippos still top the scales at a hefty quarter of a tonne or more. Nevertheless, they are dwarfed by their colossal cousins. Nose to tail, the pygmy hippo is half the length of its common counterpart, but the real difference is in bulk; it is outweighed by a factor of ten.

Rotund, thick-necked and hairless, pygmy hippos derive their glossy sheen from the tiny mucus glands that pock-mark their sun-sensitive skin. They frequent forested waterways, where they spend the day in rivers and swamps before emerging to feed at night on a variety of grasses, shoots and fallen fruit.

The reclusive and elusive pygmy hippopotamus is native to riverine forest and swamps in West Africa, with most populations confined to Liberia. Credit: Mark R Higgins/Adobe

Confined to a dwindling number of suitable sites in West Africa, pygmy hippos continue to decline drastically in number, due mainly to habitat loss and hunting. Deforestation as a result of mining, logging, agricultural expansion and other forms of human encroachment has fragmented the remaining population and left many of them living in closer proximity to people, which in turn increases the risk of further disturbance or unsustainable levels of hunting for meat.

The vast bulk – in both senses – of the world’s remaining pygmy hippos are found in Liberia, although smaller populations still survive across the border in Côte d’Ivoire, Guinea and Sierra Leone. A subspecies formerly found in Nigeria is now thought to be extinct.

Fauna & Flora International (FFI) is working with local and international partners to safeguard the pygmy hippo – along with the other species that share its threatened habitat – in Sapo National Park, Liberia’s largest protected area, and the Ziama-Wonegizi-Wologizi transboundary forest landscape, which straddles the border between Guinea and Liberia.

Camera-trap surveys have captured pygmy hippos images in both these areas, while recent field surveys have recorded footprints, faeces and feeding signs. Data collected by FFI suggest that Sapo National Park is a crucial stronghold for the species, with a density unrivalled throughout this hippo’s restricted range. Elsewhere in Liberia, state-of-the-art eDNA surveys are revealing the presence of pygmy hippos in other river systems.

Camera traps provide a vital insight into the density of pygmy hippo populations in West Africa. Credit: FFI

FFI has helped put together a national action plan for the species, which outlines clear strategies for its conservation. A nationwide reconnaissance survey is now under way – the first attempt to estimate Liberia’s total pygmy hippo population – focusing on Liberia’s key biodiversity areas.

We have also collaborated on a landscape-level assessment to identify potential conservation corridors in south-east Liberia that would benefit from increased protection – with particular emphasis on suitable pygmy hippo habitat. A central goal of the new ten-year pygmy hippo conservation strategy is to secure connectivity between all known populations of the species.

The pygmy hippo is a flagship species for Liberia’s valuable forests and for the Upper Guinea Forest as a whole, which not only harbours a wealth of biodiversity and supports local livelihoods, but also stores vast amounts of carbon, thereby helping to reduce global emissions and combat climate change.

Our work to protect this reclusive and neglected animal is an integral part of FFI’s wider conservation efforts to safeguard threatened species and habitats across the globe, but we also need governments and big business to step up to the plate, acknowledge the importance of our natural world, and start investing in our planet’s future.