Seasonality and nutrient composition of the plant diets of mona monkeys (Cercopithecus mona) in University of Lagos, Nigeria

Abstract

This study was conducted during the dry and rainy seasons of 2011 and 2012 in the University of Lagos. The aim was to determine the seasonal availability and nutrient contents of mona monkeys’ plant diets. Visual observation of feeding behaviour and opportunistic collection of discarded portions were used to determine seasonality of the food plants. Portions of the food plants consumed were subjected to proximate analyses for crude protein (CP), ether extracts (EE), crude fibre (CF), Ash, and nitrogen free extracts (NFE) contents, and fibre fraction analyses for neutral detergent fibre (NDF), acid detergent fibre (ADF), and acid detergent lignin (ADL) using standard procedures. The nutrient values for consumed plant parts as fruits, leaves, seeds and nuts, and tubers were pooled and used for descriptive statistics. Mona monkeys utilized 30 plant species as foods, of which 37 % and 48 % were available during the dry and rainy seasons respectively. Dry season food plants, Albizia lebbeck and Brassica oleracea had the highest CP values of 37.19% and 29.53% respectively. Dioscorea alata (raw) had the least CP value of 0.88%. Musa paradisiaca had the highest ADF value of 45.00%. Brassica oleracea had the highest ADL content of 30.46%. The rainy season food with the highest CP of 37.19% was Albizia lebbeck. Ripe Terminalia catappa had the highest NDF of 76.20%. Seeds (n = 4) had the highest CP value of 29.5 2.55%. Fruits (n = 10) had the highest CF of 11.09 0.63%. Leaves (n = 3) had the highest Ash of 10.07 0.40%. The plant diets utilized by mona monkeys met the 6.4-8.0% protein recommended by National Research Council for adult primates in captivity. The nutrient values of the foods in this study could serve as guide for feeding mona monkeys and sympatric species in captivity.

Keywords: Mona monkeys; seasonality of foods; nutrient composition; fibre fraction content