Good News from North-Central Africa: Largest Population of Vulnerable Common Hippopotamus Hippopotamus Amphibius Is Stable

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Good news from north-central Africa: largest population of Vulnerable common hippopotamus Hippopotamus amphibius is stable

P AUL S CHOLTE,FRANCIS N GUIMKENG and E MMANUEL I YAH

Abstract North-central Africa (i.e. Cameroon, the Central Scholte & Iyah, ). North-central Africa is home to African Republic and Chad) once held important popula- c. , hippopotamuses, mostly in Faro and Bénoué tions of large mammals, including the hippopotamus National Parks, in northern Cameroon (Tsi et al., ; Hippopotamus amphibius. Exports of hippopotamus tro- Scholte & Iyah, ). Together, these protected areas phies from Cameroon were suspended in  but the spe- cover . million ha, including  safari hunting zones, cies’ status and population trends remain poorly known. and are the last large remaining wildlife conservation refuge Using the same methodology as in  and ,we in north-central Africa (Scholte, ). The only hippopot- counted hippopotamuses in Faro National Park and border- amus population in the region that has been surveyed regu- ing hunting zones in . We counted  individuals larly, in Bénoué National Park, declined from  to  along  km of river, compared with  and  in  individuals between  and – (Scholte & Iyah, and , respectively. The stability of this population con- ). The uncertainty regarding the status of the hippopot- trasts with the declines in populations of large mammals amus population overall in Cameroon prompted the CITES across north-central Africa. We attribute this conservation Standing Committee to reconfirm the suspension of exports success to private efforts (i.e. safari hunting) compensating of hippopotamus trophies (CITES, ). In  we con- for a decline in state protection. However, the situation re- ducted a count to assess the trend of the hippopotamus mains fragile, as highlighted by an influx of transhumant population in Faro National Park, which is under pressure cattle and gold diggers. We recommend increasing pub- from gold miners and pastoralists, and to contribute to the lic–private conservation efforts, including incentives for understanding of the continent-wide decline in large terres- the safari hunting industry, which is also under pressure. trial mammals (Scholte, ). Faro National Park (, ha) has a Sudano–Guinean Keywords Hippopotamus, inventory, ivory, poaching, climate characterized by a single rainy season, with mean safari hunting annual rainfall of c. , mm. The undulating terrain is cov- ered by wooded savannah dominated by trees of the genera orth-central Africa, encompassing the northern Isoberlinia and Terminalia, and a diversified grass layer with Central African Republic, Chad and North Andropogon and Hyparrhenia species. The Faro River flows N – Cameroon, was once among the most biodiverse areas in east west, partly underground during the dry season. Sahelo–Sudanian Africa, with some of the last remaining During the wet season various intermittent rivers contain populations of large mammals (Brugière & Scholte, ). water and attract hippopotamuses and other large mam- Until , populations of large mammals in protected mals. The Park is surrounded by sport hunting zones:       areas were stable, possibly because anthropogenic pressure zone ( , ha), Voko-Bantadje ( , ha), zone       was relatively low and rainfall had recovered after the ( , ha) and zone bis ( , ha; Fig. ). – Sahelian droughts of the s and s (Scholte, ). The count was conducted during March, at the end A shift in the political–economic climate triggered erosion of the dry season, when the Faro River was the only remain- of state control and insecurity, which has resulted in marked ing source of water and the area was easily accessible. – declines in large mammals since  (Scholte, ). The Searching for hippopotamuses, observers walked through the riverbed or along its edges at a speed of – common hippopotamus Hippopotamus amphibius is − under pressure from habitat conversion and hunting for km h , splitting up when the riverbed was too wide to be – bushmeat and, increasingly, for ivory (Klingel, ; overseen, and halting for minutes each time hippopotamuses were observed. The hippopotamuses were counted until the observers reached a consensus on the number pre- sent. No submersion factor was applied as oversight over the PAUL SCHOLTE (Corresponding author) Nieuwe Teertuinen 12 C, 1013 LV Amsterdam, The Netherlands. E-mail [email protected] schools of hippopotamuses was excellent and water condi- tions were clear. Two teams, including members that parti- FRANCIS NGUIMKENG and EMMANUEL IYAH Garoua Wildlife College, Garoua,      Cameroon cipated in the count, walked from . until . ,  Received  June . Revision requested  July . with a hour break at midday. Global positioning system Accepted  October . First published online  August . (GPS) coordinates were recorded for each observation of

Oryx, 2017, 51(2), 218–221 © 2016 Fauna & Flora International doi:10.1017/S0030605315001258 Downloaded from https://www.cambridge.org/core. IP address: 170.106.202.126, on 28 Sep 2021 at 13:57:10, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S0030605315001258 The hippopotamus in Faro National Park 219

FIG. 1 Hippopotamus Hippopotamus amphibius distribution along  km of the Faro River in Faro National Park and the surrounding safari hunting zones, in Cameroon, (a) in June  (early rainy season) and (b) March  (end of dry season), with indicators of human presence.

hippopotamuses. We also recorded signs of human pres- geomorphologic riverbed features. The linear densities we ence and tracks of elephants Loxodonta africana and large observed are less than one-third of densities reported carnivores, which were clearly visible in the sandier parts from eastern and southern Africa, suggesting that variation of the riverbed (for more details see Scholte & Iyah, ). in habitat productivity also plays an important role (e.g. We used the number of guards (reported in unpublished an- Chomba, ; Scholte & Iyah, ). nual reports of the regional ministry) as an indicator of the Group sizes observed during the  and  counts in effectiveness of national park management (Bruner et al., Faro were comparable with counts in neighbouring Bénoué ). National Park (P . ., Mann–Whitney U test). A relative- We observed  hippopotamuses along  km of river, ly high number of larger groups (.  individuals) were ob- compared with  ( km) in  and  ( km) in served in Faro and, until , in Bénoué (Fig. ). . Numbers varied at certain locations along the river, We are confident in the longitudinal comparability of the mainly between the dry season () and early rainy season Faro counts because of the participation of the same key ob- () counts, probably because of differences in water servers in  and . availability; for example, the water flow downstream of the The areas further upstream of the Faro River (hunting hunting zone  camp is largely below ground during the dry zones  and , with , and , ha, respectively) season, with the exception of a single large waterhole (Fig. ). have not yet been surveyed for hippopotamuses. Based on Only a few traces of human presence (gold digging, fisher information from professional hunting guides we conserva- camps) were observed (Fig. ). tively estimate the numbers of hippopotamuses in these − We recorded linear density of . individuals km , al- zones to be  and , respectively, yielding a total popu- − most double the . km recorded in Bénoué National lation estimate of c. , hippopotamuses on the Faro Park (Scholte & Iyah, ). Given the homogenous vegeta- River, thus exceeding the estimated  individuals in the tion along the Bénoué and Faro Rivers, we attribute the dif- . million ha Arly–Pendjari System in West Africa ference in hippopotamus densities to the characteristics of (Bouché, ). If confirmed, this indicates that the Faro the Faro river bed, which is – times wider and with up population is not only the largest in north-central Africa to  times higher maximum discharge than the Bénoué but in the entire west-central African region (Senegal to River (near park headquarters; Olivry, ). For a popula- Chad). tion of c. , individuals along  km of the Luangwe The number of armed national park guards in Faro has River (Zambia), Chomba () concluded that food was increased since the s, varying from  to  since ; the main factor regulating population size, whereas the there were  guards in . In contrast, in the surrounding population density distribution was influenced by hunting zones , , bis and Voko-Bantadje there were ,

reduced to  for –, including only one for four hunting zones along the Faro River (, bis,  and ); i.e. c. % of the hunting block population. Such a reduced quota compromises the viability of sport hunting enter- prises; for an analogous discussion on lion hunting see Lindsey et al. (). More could be gained by transparent quota setting as well as controlling illegal hunting and ivory trafficking. Despite the successful protection of the hippopotamus thus far, we recommend increased efforts to recognize the efficiency of public–private conservation efforts, including incentives for safari hunting. There is further urgency to de-  FIG. 2 Hippopotamus group sizes in Faro National Park (Fig. ) sign an economically viable wildlife-based land use system during – compared with Bénoué National Park during in North Cameroon, comprising governmentally managed – and –. Sources: Faro National Park (total of  observations; Zibrine, ; this study); Bénoué National national parks, privately managed hunting zones and Park (–: total of  observations, Scholte & Iyah, ; community hunting zones, with benefits used to ensure –: subsample of  observations). long-term commitment to their conservation by local communities.

,  and  guards, respectively, in ; i.e. one guard per     , ha in Faro National Park, one per , ha in hunting Acknowledgements zone , one per , ha in zone , one per , ha in zone bis and one per , ha in Voko-Bantadje. The We thank Seiny Djobdi (former warden, Faro National hunting zone guards are not only more numerous but also Park) and Koen Maes (hunting zone ) for their assistance. better equipped, with motorcycles, GPS and field rations, The African Wildlife Foundation funded the fieldwork than the Faro National Park guards. through the Faro Conservation Association. We thank Faro National Park is the only the national park in North Hans Bauer for his comments on the manuscript. Cameroon that has remained almost without road infra- structure. In  c.  km of tracks were constructed, of which only  km is now functional. This is in contrast References with the situation in the hunting zones, where, for example,  .   hunting zone has km and Voko-Bantadje km BOUCHÉ,P.() Hippopotamus of the W-Arli-Pendjari-Oti- of tracks (i.e. a – times higher road density), facilitating Mandouri-Keran ecosystem. Suiform Soundings, , –. more efficient control. BRUGIÈRE,D.&SCHOLTE,P.() Biodiversity gap analysis of the Hunting zone  (Fig. ) in particular plays an important protected area system in poorly-documented Chad. Journal for Nature Conservation, , –. role in buffering the northern part of Faro against possible BRUNER, A.G., GULLISON, R.E., RICE, R.E. & DA FONSECA, G.A.B. incursions. As in neighbouring Bénoué National Park () Effectiveness of parks in protecting tropical biodiversity. (Scholte & Iyah, ), the few observed signs of illegal Science, , –. human presence in Faro (Fig. ) belie the multiple pressures CHOMBA,C.() Factors affecting the Luangwa (Zambia) hippo on the Park. In Bénoué linear densities of hippopotamus population dynamics within its carrying capacity band. International Journal of Biodiversity and Conservation. , –. have remained constant over the last decade only in the CITES () Notification to the Parties: Review of Significant Trade vicinity of the park headquarters and two sport hunting in Specimens of Appendix-II Species. Https://cites.org/sites/default/ camps (Scholte & Iyah, ). We attribute the conservation files/notif/E-Notif--_.pdf [accessed  December ]. success in Faro to the private protection afforded by the ad- KLINGEL,H.() Hippopotamus amphibius. Common jacent safari hunting operations, which compensates for re- hippopotamus. In The Mammals of Africa, Volume VI: Pigs, duced state protection efforts. However, the situation Hippopotamuses, Chevrotain, Giraffes, Deer and Bovids (eds J. Kingdon & M. Hoffmann), pp. –. Bloomsbury Publishing, remains fragile, as highlighted by an influx of transhumant London, UK. cattle and gold miners. LINDSEY, P.A., BALME, G.A., BOOTH, V.R. & MIDLANE,N.() The Of a total quota of  set by the Ministry of Forests and significance of African lions for the financial viability of trophy Wildlife,  (%) hippopotamuses were hunted legally dur- hunting and the maintenance of wild land. PLoS ONE, (), e.  ing –, the majority along the Faro River ( of  OLIVRY, J.C. ( ) Fleuves et Rivières du Cameroun. Monographies Hydrologiques . ORSTOM, Paris, France. were hunted during –). Possibly as a response to SCHOLTE,P.() Towards understanding large mammal population critical reports on lion Panthera leo and hippopotamus po- declines in Africa’s protected areas: a West-Central African pulations by the EU and CITES (), the quota was perspective. Tropical Conservation Science, , –.

SCHOLTE,P.&IYAH,E.() Declining population of the Vulnerable Biographical sketches common hippopotamus Hippopotamus amphibius in Bénoué National Park, Cameroon (–): the importance of PAUL SCHOLTE is an ecologist leading organizations in conservation and conservation presence. Oryx, , –. natural resource management in a development context. Throughout the  TSI, E.A., TOMEDI, E.M., TALLA, F.N. & NGUIMKENG, D.L. () s heworked in the protected areas of North Cameroon, and after sev- Status and dynamics of hippopotamus (Hippopotamus amphibius) eral years in Yemen and Rwanda he returned to Central Africa, where he during the rainy season in Faro National Park, Cameroon. Journal of is building a coalition to respond to the crisis that is compromising the Agriculture and Biological Sciences, , –. future of the region’s protected areas. FRANCIS NGUIMKENG studied the  ZIBRINE,M.() Distribution et dynamique des populations hippopotamus population of Faro National Park in , and trains mid- d’hippopotames et des espèces liées aux galléries forestières career wildlife professionals from francophone Africa in ornithology. dans le parc national du Faro. Internal report. WWF, Garoua, EMMANUEL IYAH lectures in zoology and animal ecology and is inter- Cameroon. ested in comparative hippopotamus ecology and behaviour.