Geophagy by the bonnet macaques (Macaca radiata) of southern IndiaBonnet macaques (Macaca radiata) in the Marakkanam Reserved Forest of southern India consume termitaria soils. Samples from the ingested termite mounds are compared with samples taken from the surrounding uneaten soils in an attempt to determine why the termitaria soils are eaten. Particle size, clay and primary mineral composition, geochemistry and scanning electron microscopic analyses are used to search for a possible explanation for geophagy among the bonnet macaques. Kaolin minerals abound throughout the Marakkanam soil sample suite. But the termitaria soils are distinguished by the presence of small amounts of smectite. An abundance of kaolin minerals in combination with small amounts of smectite strongly resembles the mineralogy of eko, a traditional African remedy for stomach ailments, and Kaopectate™, a western anti-diarrhoeal preparation. The percentage of mature leaves and fruits of Azadirachta indica consumed by the bonnet macaques is relatively high. Plant feeding deterrents, such as, acid detergent fibre (ADF) and the inherent nature of the fruits of Azadirachta indica, when consumed in large quantities to act as a purgative, could cause gastrointestinal upsets and diarrhoea. At Marakkanam, bonnet macaques ingest termitaria earth that would act as a pharmaceutical agent to alleviate gastrointestinal upsets and control diarrhoea.
Krishnamani, R. and W. C. Mahaney. (2000). Geophagy among primates: Adaptive significance and ecological consequences. Animal Behaviour, 59(5): 899-915.
Voros, J., W. C. Mahaney, M. W. Milner, R. Krishnamani, S. Aufreiter and R. G. V. Hancock. (2001). Geophagy by the bonnet macaques Macaca radiata) of southern India: a preliminary analysis. Primates, 42(4): 327-344.
Mahaney, W. C. and R. Krishnamani. (2003). Understanding geophagy in animals: Standard procedures for sampling soils. Journal of Chemical Ecology, 29(7): 1503-1523.