Damage by baboons to pine plantations in South Africa : with special reference to the ecology of three troops of baboons in the Western Cape

[摘要] ENGLISH ABSTRACT: Baboon density in the study area was lower than in other studies,probably as a result of removal programmes. Troops had seasonaldifferenccs in home range utilization. Home range inc reased insummer as troops exploited local crops, and permanent water points.All troops showed a preference for plantations, as they providedshelter, food and protection.Data on feeding habits was collected by faecal analysis as baboons'fear had developed a fear of humans. Favoured foods weremonocotyledonous and dicotyledonous plants, bulbs, seeds and cones.Xylem, phloem and cambium cells did not constitute a largeproportion of the diet, nor was there any seasonal variation inoccurrence. Dicots were selected in spring, pine cones in autumn(probably a selection for seeds not cones), insects in summer andbulbs in winter. The five favoured items were found throughoutthe year. Baboons have a few staple items which they supplementwith seasonally available foods. Bark stripping is inhe.rent inbaboons, despite the low energetic value of bark tissues. It isnot known why all troops in plantations do not strip. Pine seedsand grasses play an important role in the diet, and may attractbaboons into the plantations.Some mineral nutrients in the pine tree tissues varied seasonally.Levels in these tissues were comparable with levels in many plantsconsumed by baboons elsewhere. Zinc levels were higher in treesdamaged by baboons than in other trees. Baboons may thus beselecting for zinc. This phenomenon, and the implications formanaging baboon damage, needs further research.37% of plantations in South Africa experienced baboon damage. Thiswas not restricted to any particular area or species of pine. Lessthan 15% of the compartments on any station showed damage. Onaverage, less than 25% of the trees within a particular compartmentwere damaged. Increase in damage within a plantation was isolated.No relationship was found between damage and environmental factors.Less than 2% of the total compartments in South Africa and lessthan 1% of the total area afforested show damage.Baboon damage at Kluitjieskraal State Forest affected 6% of all compartments.Less than 25% of the trees in these compartments were affected.Damage to the trees varied in severity. Patternsof damage were determined and were found to differ between areaswithin a plantation.A precise estimate of financial losses on a national scale is notpossible due to many complicated factors and the considerable lackof available data. An assessment of-the severity of the damage isprovided. Authorities must determine whether it is practical and economical to introduce control measures. Indications are that thelosses in South Africa amount to less than R5 000 000 on presentareas afforested.Information on control programmes in the Western Cape is scarce,although control has been carried out in Forestry areas for manyyears. The effectiveness of electric fencing to decrease damagelevels is discussed. It is imperative to understand the populationdynamics of specific baboon populations to exercise effectivecontrol.

[发布机构] Stellenbosch University