The ecology and behaviour of the common hippopotamus, Hippopotamus amphibious L., in Katavi National Park, Tanzania : responses to varying water resources

摘要: Katavi National Park (KNP) is a stronghold for hippopotami in Tanzania. To predict the probable effects of future changes water availability, annual variations rainfall, river level, discharge, ground levels and lateral extent swamps used by hippopotami, were related to their behaviour, distribution abundance aquatic shelter sites. Rainfall did not change consistently between 1950 2010. In contrast flow decreased over 1990 It concluded that these reductions have been caused an increase irrigation rice fields increasingly planted upstream regions catchment area. Rainfall fell pronounced cycle. The wet season started December, increased January, February reaching peak March. dry lasted from May November. Variation height, biomass greenness layer swards feeding closely mirror this pattern rainfall. As progresses become aggregated remaining sites day, wallow thermoregulate with concomitant depletion nocturnal grounds close sites. Five observation chosen, representing gradient amount persisting through season. Hippopotami showed spatial differences activity budgets frequency behavioural events at sites, which consistent way they responded variation availability seasons. Extrapolating findings responses global climate land use, I conclude implementation existing national laws governing diversion rivers up-stream park will be crucial maintaining vigorous populations KNP. Similar problems area scale occur other Parks Africa.