Diet of pine plantation and non-plantation ranging baboon (Papio ursinus) groups with reference to bark consumption in the eastern highlands of Zimbabwe

Abstract

Bark stripping of pine trees by chacma baboons in plantations of the Eastern Highlands of Zimbabwe has been on the rise leading to the assumption that bark constitutes baboon food. The study investigated diet variation among habituated bark stripping and non-stripping, plantation and non-plantation ranging baboon groups primarily to determine the noteworthy of pine bark in baboon diet. Food resources contributing >0.1% of the observations as well as pine bark were noted by group and season. Feeding observations were done through hourly instantaneous scan sampling which lasted for 5 min. During the scan, data on food items where possibly identified on species level, and part eaten were noted. To determine feeding variation, one way analysis of variance was applied with feeding percentage observations as the dependent variable and baboon groups, seasons, consumed species as well as plant parts as independent. The percentages of feeding observations were compared across baboon groups, seasons, consumed species and plant parts through the generalised linear model using SPSS version 15 (2006). Differences between means were tested using Bonferroni post hoc tests with a 5% level of significance. Feeding observation percentages did not vary significantly (P > 0.05, F = 1.02; df = 2, N = 960) across groups and seasons (P > 0.05, F = 1.957; df = 2), food species and plant parts were however, consumed at significantly (P < 0.05, F = 2896.85, df = 24) varying percentages. Bark consumption was lowest with 0.03 ± 0.16%. Pine bark is therefore not a preferred baboon food item. The establishment of plantations provided high quality food in the form of seed for the baboons.   Key words: Baboon groups, bark consumption, consumed species, feeding observations, food items.