Feeding behaviour of the forest elephant and logging impact on fruit production in the kakum conservation area
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Date
2004-11-14
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Abstract
This thesis presents the results of a series of studies on elephants in the Kakum Conservation Area in Ghana, after twelve months (July 2001 to June 2002) of ecological and ethological monitoring.
The reproductive and foliage status of elephant fruit-tree sources were monitored in the Kakum Conservation Area, Ghana, along strip transects. Phenological activity was variable among and between species. Drought conditions trigger leaf shedding while the onset of rains induce leaf flushing to be later succeeded by reproductive changes. Hence the amount of rainfall in the wet season influences the amount of fruits produced in the dry season and consequently, its diversity. However, the best climatic predictor of fruiting was minimum temperature.
Elephant food included minimum plant parts of 42 species. On one level, 360 elephant dung piles were examined yielding fruit fragments representing 29 fruit species eaten by elephants, although with a higher reliance on Panda oleosa, Parinari excelsa and Tieghemella hecklii. There were seasonal differences in the quantity and diversity of fruits eaten. Fruit availability was highest in the month of October. On another level, data taken on fresh feeding signs showed an extra 13 species of plants parts recorded to be either browsed upon or barked. There was a high probability of barking activities in close canopy areas and browsing in open canopy areas.
Investigations into the effect of logging on some aspects of the forest ecology showed that logging has significantly reduced the density of biggest (dbh > 0.82 m) trees and may be responsible for uneven distribution in certain highly valued timber trees. Logged species also lacked smaller and bigger size classes. An experiment on fruit production showed that bigger trees produce disproportionately more fruits than smaller ones; hence logging which removes the biggest trees may cause a disproportionately large reduction in fruit production and supply to frugivores especially elephants.
Crop raids by elephants were monitored in ten permanent study sites (lxlkm2) randomly distributed on the periphery of the study area. June was the peak (2.4 raids per sq km) month of crop raiding activities whilst October experienced the least (0.1 raids per sq km). Natural factors like fruit availability within KCA greatly reduced the risk of raids in nearby farms. At the level of the farm, the maturation periods of maize farms presented the strongest risk. Environmental factors like rainfall intensity, indirectly affects crop raids by promoting the growth and maturation of maize farms around KCA.
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A theses submitted to the School of Graduate Studies, Kwame Nkrumah University of Science and Technology in partial
fulfilment of the requirements for the award of Master of Philosophy degree in Wildlife and Range Management, 2004