Project status

The iconic pygmy hippo

Hands on in the field and behind the scenes, we’ve worked to protect and support the recovery of the pygmy hippo found in the threatened Upper Guinea forest hotspot of West Africa. 

Logging, mining and other human activities have damaged the iconic species’ forest home. It’s brought them into much closer contact with people, putting them at greater risk of hunted and disturbed by human activities. 

Our work has helped to protect the 2,000-2,500 remaining individual pygmy hippos, an Endangered and Evolutionarily Distinct Species. 

Our pygmy hippo conservation work 

ZSL's EDGE of Existence Programme identified pygmy hippos as a priority for conservation in 2007, and between 2007 and 2012, ZSL worked to conserve them in Liberia’s Sapo National Park and Loma Mountains in Sierra Leone. We carried out research to understand pygmy hippo ecology, distribution and behaviour and work with local communities and government wildlife authorities to protect them.  

London Zoo and Whipsnade Zoo also carry out captive breeding of these animals. ZSL also led the production of the IUCN SSC Regional Pygmy Hippo Conservation Strategy in 2010. 

Pygmy hippo at London Zoo
A pygmy hippo at Whipsnade Zoo fresh eating vegetables on the ground
  • 2,000-2,500
    individual pygmy hippos still exist (population estimate, 1993)
  • 2007
    the year ZSL's EDGE of Existence Programme identified pygmy hippos as a priority for conservation
  • Why have we been protecting pygmy hippos?  

    A 1993 population estimate suggested that only 2,000-2,500 pygmy hippo individuals still existed, and their numbers are likely to have declined since then. They are classified as Endangered on the 2015 IUCN Red List of Threatened Species.  

    A distinct pygmy hippo subspecies (C. liberiensis heslopi) that once existed in Nigeria has gone extinct. These declines result from habitat loss and hunting. The fragmentation and destruction of the pygmy hippo's forest habitat due to logging, mining, agrobusiness expansion and farming activities have brought pygmy hippos into closer contact with humans and as a result they are at much greater risk of being hunted and disturbed by human activities. 

    What has our pygmy hippo conservation work achieved?  

    ZSL pioneered in situ conservation of pygmy hippos in Liberia between 2008 and 2012, in collaboration with Fauna and Flora International (FFI) and Liberia’s Forestry Development Authority (FDA). Because the pygmy hippo is so poorly known, we carried out surveys of where they exist and threats to their populations, using methods such as camera trapping.  

    In 2008, ZSL and our partners obtained the first photos of pygmy hippos in the country. In November 2010, ZSL held the first ‘International Pygmy Hippo Conservation Strategy Planning Workshop’ in Liberia and produced a regional conservation strategy under the umbrella of the IUCN SSC Hippo Specialist Group. 

    The strategy articulated the vision, goal, objectives and actions required for in situ conservation of pygmy hippos. Also in 2010, ZSL began working with a team from Njala University in Sierra Leone to research and protect a population of pygmy hippos around Loma Mountain in northern Sierra Leone. 

    Find out more about our work with EDGE species  


    • Fauna and Flora International  

    • Liberian Forestry Development Authority 

    • Njala University 

    • Conservation and Wildlife Management Unit 

    • Forestry Division 

    • Sierra Leone


    • IUCN  

    • Mohammed bin Zayed Species Fund 

    • USFWS; SeaWorld/Busch Gardens  

    • Attica Zoo  

    • Aalborg Zoo 

    • Zoo Basel 

    • Gaia Zoo  

    • Tierpark Chemnitz  

    • Fundacion Bioparc 


    Urgent action to stop the devastation of critical species and habitats by helping people and wildlife live better together, is the only way to save the natural world we love and depend upon. That’s where ZSL comes in, and where you can play your part.