Forage preference by African elephants (loxodonta africana) in rimoi national game reserve, Keiyo County, Kenya

Abstract

The feeding ecology of the largest land mammals has attracted much attenti'on, not only for the sheer quantity of food consumed, but also the variety of plants selected and their impact on vegetation. With continuous loss of habitat, qualitatively as well as quantitatively, elephants are forced to extend their range. This study was carried out between April and November 2010. The data on preferred forages by elephants were obtained by making a systematic record of the feeding behaviour. Their diet was deduced from records of plants which showed obvious signs of recent elephant use. The collected data were coded in Statistical Package for Social Sciences (SPSS ver. 17.0) and analyzed by descriptive methods. Results showed that the most preferred wild forage were Acacia tomlis (22.5%) followed by Balanites aegyptica (14.8%), then Acacia mellifera (9.6%) and Zizyphus mucronata (7.5%) and Acacia brevispica (7.1%). Elephants too showed preference for crops. There were significant differences in the crop raiding patterns ("l = 36.443, df'= 5, P = 0.0003). Based on the findings, the most preferred crops and therefore most raided was maize (86.5%) followed by millet (51.4%) and green grams (34.8%), while the least raided crops were cowpeas (16.8%) followed by millet (7.3%). This study showed that elephants consume different plant species with varying degree of preference. The daily diets of African elephants in Rimoi conservation area were selected entirely from the indigenous vegetation. Nineteen wild plant species viz., Acacia "'(ortilis, Balanites aegyptica, Acaia mellifera, Zizyphus mucronata, Acacia brevis pica, Acacia hamulosa, Acacia obyssintca. Combretum spp., Grewia bicotor, Cissus rotllndifo/ia, Cynodon dactylon, Eragrostis minor, Achyranthes aspera; Sanseviera intermedia, Sarcostemma viminale, Grewia mollis, Chloris pycnothrix, Ficus spp. and Aloe spp. were used in different ways by elephants as food in this region. Results also showed that the use of the plant species is more skewed towards the acacia plants and is likely to affect the normal functioning of the ecosystem, which indicate that elephants would be implicated in vegetative change in structure and composition through their varied seasonal choice of food items that include falling and debarking in the dry season.