Behavioural ecology of duikers (Cephalophus spp.) in forest and secondary growth, Tai, Cote d'Ivoire
The behavioural ecology of duikers (Cephalophus spp.) was studied in mature forest and mixed secondary vegetation around TaI National Park, Cöte d'Ivoire. The most common species in both vegetation types was C. maxwelli, followed by C. dorsalis, C. ogilbyi, C. niger, C. zebra and C. lentinki in mature forest, and C. niger, C. dorsalis and C. sylvicultor in secondary vegetation. Population surveys were carried out by a number of methods. Transect censuses by night were found most efficient in mature forest, whereas in secondary vegetation, only pellet transect censuses and drives into nets were possible. C. maxwelli populations were estimated at about 63 km2 in mature forest and 79 km2 in secondary vegetation. Duikers were primarily frugivorous, but the proportion of leaves taken increased in the season of fruit scarcity. Fruit abundance in different habitats increased with the age of the vegetation. Six C. maxwelli in mature forest and four in secondary vegetation were radio-collared to determine ranging patterns and social behaviour. They were diurnal and lived in groups of one male with one or two females and young. Home ranges, which were about 5 ha in size in mature forest and 3.6 ha in secondary vegetation, were defended by males, and the boundaries were marked by latrine areas by both sexes. In mixed secondary vegetation, all habitats were used except open fields and bamboo thickets. Implications for conservation and management are discussed. The continued preservation of mature forest and the control of poaching are essential for the survival of the three rarer species (C. -jentinki, C. zebra and C. ogilbyi). The control of poaching must precede any programme of sustainable harvesting of the more abundant species, which could be carried out in secondary vegetation. Duiker farming may be possible if low-cost sources of fencing and forage can be identified.