Ecology of the Sitatunga

Ecology of the Sitatunga (Tragelaphus spekei selousi Rothschild, 1898) in the Bangweulu swamps, Zambia, Central Africa
by
I.P.A. Manning

Research into the ecology of the sitatunga (Tragelaphus spekei Rothschild, 1898.) in the south-east Bangweulu, Zambia, was carried out between 1973 and 1976. The sex ratio for sitatunga does not differ significantly from 1:1, although 47.3% of the population are adult females and 25.6% adult males, 12.1% immature males, 4.3% immature females and 10.6% calves. Two conception peaks are related to the onset and cessation of the rains with breeding occurring throughout the year. Sitatunga occur singly (50%), in twos (22.2%) or in threes (16.7%). Females and their calves are the only group with any integrity. The maximum number observed in a group was 7. The minimum home range for males is 0.0363 km2 and for females 0.176 km2. Aggression and the mutual avoidance of dominant males suggests territoriality. Sexual dimorphism is marked. Pelage colouration is variable. The white facial markings are important in male agonistic displays. Criteria for relative age determination of sitatunga were derived from eruption and attrition sequences of impressions taken from maxillary teeth. Males reach a theoretical maximum weight of 106 kg at 8.1 years and females 51.5 kg at 7.34 years. Males are 54.6% heavier than females and maximum horn length is achieved at 7.5 years. Age is significantly correlated with weight, horn length and the length/weight index. The mean horn length for adults is 64.2 cm (measured according to Rowland Ward’s) and the mean front hoof length, for both sexes, is 7.6 cm.