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Tracing the Source of the Elephant And Hippopotamus Ivory from ...

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ehavior in <strong>the</strong> tropical closed canopy forests <strong>of</strong> two national parks in West and Central<br />

Africa. Here <strong>the</strong> diet is heavily browse with little reliance on grass. Bia National Park is<br />

located in <strong>the</strong> forest belt <strong>of</strong> western Ghana, receives 1500 mm rain per annum, and is<br />

described by Short (1981) as lowland tropical rainforest with characteristics <strong>of</strong> evergreen<br />

and semi-deciduous forest. Browse (mainly woody leaves and stems) constituted <strong>the</strong><br />

bulk <strong>of</strong> elephants’ diet in Bia, in addition to some fruit. Grass, on <strong>the</strong> o<strong>the</strong>r hand, is<br />

almost completely absent <strong>from</strong> Bia NP and thus does not contribute to <strong>the</strong> diet <strong>of</strong> <strong>the</strong>se<br />

elephants. Although closed canopy forests dominate <strong>the</strong> landscape, <strong>the</strong> elephants<br />

preferred to browse in open forest and old forest gaps. The only feeding activities that<br />

took place in closed forest were barking and ga<strong>the</strong>ring <strong>of</strong> fruits. Accordingly, vegetation<br />

cover type is not utilized in proportion to its occurrence, and elephants’ avoidance <strong>of</strong><br />

closed forest and preference for open canopy with dense ground vegetation is also<br />

supported by Wing and Buss (1970) and Laws et al (1975) (cited by Short 1981: 184).<br />

Ano<strong>the</strong>r interesting finding by Short was that elephants in different habitats prefer<br />

different types <strong>of</strong> trees, depending on <strong>the</strong> total vegetation assemblage. Two species,<br />

Pipideniastrum africanum and Parinari excelsa, heavily barked in o<strong>the</strong>r studies (see<br />

Wing and Buss 1970 and Laws et al 1975), were not barked at all in Bia NP. Also, <strong>the</strong><br />

elephants are highly selective, preferring to bark <strong>from</strong> a small number <strong>of</strong> species. Short<br />

<strong>of</strong>fers several explanations for this phenomenon:<br />

(i) elephants with a greater range <strong>of</strong> choice in forest, select alternative species;<br />

(ii) palatability or calcium content may differ for <strong>the</strong>se species between areas;<br />

(iii) elephants' need for a particular mineral may vary between areas;<br />

(iv) learned preferences may differ between areas (Short 1981: 184).<br />

105

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