A mix of community-based conservation and protected forests is needed for the survival of the Endangered pygmy hippopotamus Choeropsis liberiensis A NNIKA H ILLERS,GRAEME M. BUCHANAN,JERRY C. GARTEH,SOLOMON M. TOMMY M OHAMED L. FOFANA and J EREMY A. LINDSELL Abstract The contribution of protected areas to biodiversity Keywords Agricultural expansion, community-based con- conservation is well attested but many taxa in many regions servation, community forests, large mammals, protected remain dependent on the unprotected wider landscape. To area, pygmy hippopotamus, species distribution model, develop conservation plans for large mammals such as the Upper Guinea Forest ecosystem Endangered pygmy hippopotamus Choeropsis liberiensis of To view supplementary material for this article, please visit West Africa’s Upper Guinea Forests it is critical to under- http://dx.doi.org/./SX stand the importance of unprotected land. Despite being a conservation priority, little is known about the habitat asso- ciations of this species, or its distribution across its range. Through a combination of field surveys, species distribution Introduction models and community questionnaires we investigated the use of unprotected areas by the pygmy hippopotamus in the rotected areas are the foundation for global efforts to Sierra Leone–Liberia border region. We found signs of Pconserve biodiversity and natural ecosystem processes the species in of -km cells surveyed. Our analysis (Rodrigues et al., ; Laurance et al., ). However, ana- suggested that the species is reasonably widespread in this lysis of threatened birds, mammals, amphibians and reptiles region and is associated with major rivers. It occurred at both continental and global scales suggests that protected close to, but rarely within, large areas of intact forest, and areas offer inadequate coverage of the ranges of these groups .% of pygmy hippopotamus signs were recorded outside (De Klerk et al., ; Rodrigues et al., ; Beresford et al., protected areas. The expansion of the protected area net- a,b; Butchart et al., ). Multiple-use landscapes and work in this area is unrealistic in Sierra Leone and to unprotected areas are important for species survival some extent in Liberia, mainly because of anthropogenic (Gardner et al., ; Perfecto & Vandermeer, ), espe- pressure and the overlap of proposed protected areas with cially where the existing network of protected areas does not ’ mining and logging concessions. Thus pygmy hippopot- entirely cover species ranges and suitable habitats; e.g. for amus conservation activities in the region need to include some large mammalian carnivores (Forrest et al., ; programmes on community lands while maintaining a ro- Swanepoel et al., ) and migratory herbivores (Western bust network of protected forests. Community-based con- et al., ). In some cases the expansion of the protected servation of the pygmy hippopotamus may prove valuable area network is recommended for more effective protection for other threatened and endemic species that are not con- (Forrest et al., ; Tweh et al., ) but this may not always fined to protected areas in this region. be feasible (Butchart et al., ), especially in regions where conservation efforts compete with other land uses, such as logging, mineral extraction and agriculture. In many tropic- al regions, such land use conflicts represent a threat not only to remaining natural habitats outside protected areas but ANNIKA HILLERS* (Corresponding author) and GRAEME M. BUCHANAN RSPB even to the protected areas themselves (Forrest et al., ; Centre for Conservation Science, The Royal Society for the Protection of Laurance et al., ; Tweh et al., ). A rapidly increasing Birds, The Lodge, Sandy, Bedfordshire, SG19 2DL, UK E-mail [email protected] human population is predicted to result in a further major expansion of tropical agriculture and associated encroach- JERRY C. GARTEH Society for the Conservation of Nature of Liberia, Congotown, Monrovia, Liberia ment of protected areas, particularly in Sub-Saharan SOLOMON M. TOMMY and MOHAMED L. FOFANA, Gola Rainforest National Park, Africa and South America (Laurance et al., ). The per- Kenema, Sierra Leone sistence of large mammals in such regions will therefore de- JEREMY A. LINDSELL A Rocha International, London, UK pend to a great extent on their ability to survive in such *Also at: Gola Rainforest National Park, Kenema, Sierra Leone mixed landscapes. Received July . Revision requested September . Within the forest zone of West Africa, protected areas Accepted February . cover c. % of the remaining Upper Guinean Forest Oryx, Page 1 of 10 © 2016 Fauna & Flora International doi:10.1017/S003060531600020X http://journals.cambridge.org Downloaded: 08 Jun 2016 IP address: 108.171.128.188 2 A. Hillers et al. ecosystem (CEPF, ). In Liberia and Sierra Leone only in south-eastern Sierra Leone, and presumably also the and % of the total land area, respectively, is officially pro- Gola National Forest in western Liberia, may constitute an tected (Junker et al., ; UNEP, ). These figures sug- important core area for the species (Hillers, ). The dis- gest that the protected area coverage in the region is covery of what could be a substantial population highlights inadequate, and falls below the Convention on Biological how poorly known the species’ distribution is. Diversity Aichi Target of at least % (CBD, ). We used records of pygmy hippopotamus occurrence Meanwhile, forests in this region have been severely de- collected during field surveys and using community ques- pleted and fragmented in recent decades (Mittermeier tionnaires to assess the species’ distribution in the Gola re- et al., ). Where forests are cleared they are replaced gion. We used field data to develop species distribution with low-intensity rotational agriculture. models that predicted the potential distribution of the The remaining forests harbour a number of threatened pygmy hippopotamus, and described the species’ basic habi- large mammals, some of which are known to range beyond tat associations. We were thus able to identify the extent to the bounds of protected areas (Merz, ; Junker et al., which the pygmy hippopotamus might occur in protected , ). Of these, the pygmy hippopotamus Choeropsis and unprotected areas, and where suitable habitat was lo- liberiensis, categorized as Endangered on the IUCN Red List cated both inside and outside the protected area network. (Ransom et al., ), is the largest species that is entirely en- Besides advancing our understanding of the role of unpro- demic to the Upper Guinean Forest and is therefore tected areas in general biodiversity conservation in this re- amongst the most vulnerable to habitat loss and fragmenta- gion, these data are critical if targeted and effective tion in the region. The pygmy hippopotamus is restricted to conservation interventions are to be implemented for this four countries (Sierra Leone, Liberia, Guinea and Côte species in particular. d’Ivoire; Lewison & Oliver, ), all of which are among the least developed countries in the world (UNDP, ). In recent decades, forest loss and fragmentation have Study area contributed to a reduction in the occupied range of the We conducted field work in the Gola Rainforest National species (Lewison & Oliver, ; Mallon et al., ; Park and its surroundings (c. ,, ha) in south-eastern Hodgkinson et al., ). The pygmy hippopotamus is also Sierra Leone and in the Gola National Forest (initially – threatened by poaching and human wildlife conflicts (e.g. c. , ha) in western Liberia, the whole area hereafter Greengrass, ; Hillers & Muana, ; Koroma, ; referred to as Gola (Fig. ). After the completion of field Conway, ; Conway et al., ), although there are no work, the area of the Gola National Forest was reduced by detailed data concerning the extent of these threats. Little , ha and part of our survey sites that were initially in- is known about the ecology and behaviour of the pygmy side the protected area now fall within community land. hippopotamus, and there are no reliable population esti- Natural vegetation in Gola is lowland moist evergreen – mates. The most recent estimate is , , individuals forest, and annual rainfall is c. , mm, falling in one (Mallon et al., ). The prevailing view is that protected season. Dominating families of the woody vegetation are areas harbour the majority of the population (Mallon Leguminosae-Caesalpinoideae, Euphorbiaceae, Leguminosae- et al., ; IUCN, ) but the importance of habitats out- Mimosoideae and Sterculiaceae (Klop et al., ). The study side protected areas remains unclear. Although most recent area is drained by three major rivers: the Moa River to the west; records have come from within protected areas (Collen the Moro River, marking the boundary between Sierra Leone et al., ; Mallon et al., ) this may represent sampling and Liberia in the eastern part of Gola; and the Mano River, bias, as such sites are often targeted for biodiversity surveys. flowing through the Liberian Gola National Forest and along Furthermore, riverine habitats can be poorly represented in the international border in the western part of Gola. protected areas (Nel et al., ) but are presumably critical for the pygmy hippopotamus, and in fact protected area sta- tus can mean little in a region where many are poorly funded Methods and ineffective (Brugière, ; Henschel et al., ). We undertook surveys for the pygmy hippopotamus Data on the distribution of the pygmy hippopotamus