A review of some aspects of the ecology, population trends, threats and conservation strategies for the common hippopotamus, <i>Hippopotamus amphibius</i> L, in Zimbabwe

Abstract

This review explores some ecological aspects of the common hippopotamus (hippo), Hippopotamus amphibius L, threats to its population and  contextual peculiarities affecting its conservation in selected water systems in Zimbabwe. Scoping surveys of literature and thematisation of common issues related to hippo ecology, human-hippo conflict and conservation were used for data collection. Hippos play integral ecological roles,  such as habitat engineering through track creation in water systems, nutrient recycling by swirl spread of highly organic faeces, harbouring commensal water birds, parasites and leeches. Regardless, the hippo population is not well documented for the country with indications of sharp declines in freshwater systems during the period 1982 to 1992 and gradual recovery thereafter. Habitat degradation, water pollution, climate  change, drought-induced extreme water level fluctuation, poaching and deliberate culling, as part of problem-hippo control (PHC), are key drivers of hippo population declines. However, it appears much of the attention is on human-hippo conflict and its consequences, resulting in negative  perceptions among human communities. Commercial breeding of hippos for non-consumptive tourism, and export-orientated meat, and ethnomedical mimics of hippo sweat and milk products are new, potentially viable, but unexplored options for conserving and increasing the population of the species in Zimbabwe. Currently, it appears more anti-hippo poaching patrols and awareness campaigns especially in water systems outside protected areas may be key to sustaining the current hippo population. For the future, it is essential to increase the scope for hippo census data to include water systems inside and outside protected areas for sustainable conservation of the species in the country.

Keywords: ethnomedicine, freshwater conservation, human-hippo conflict, sustainability