Ecology and distribution of the pancake tortoise, Malacochersus tornieri in Kenya

Abstract

Field investigations on the ecology, distribution and conservation of the pancake tortoise Malacochersus tornieri in Kenya were conducted from September to December 1998 and from March 2001 to April 2002. This crevice-dwelling tortoise inhabits Precambrian rock outcrops and kopjes that are discontinuously distributed throughout the arid and semi-arid lands of Kenya and Tanzania. However, suitable micro habitats are sparse and this accounts for its patchy distribution. The pancake tortoise is more widespread in Kenya than previously thought, ranging from the south-east to the north. Two sub-populations South and North of the volcanic Nyambene Hills exist. Density at study sites differed significantly and abundance of particular age groups is dependent on season. Activity outside crevices is very limited, occurring mainly during the wet season. In the dry season individuals aestivate. There is no marked sexual dimorphism in terms of size and colouration, and no significant difference in mean body weight and straight-line carapace length between sexes. There is a significant positive linear correlation between straight-line carapace length and body weight. The observed sex ratio is 1:1. Movement is very limited and centred around rock refuges. Males are more wide ranging than females. Adults dominate in the age structure of the pancake tortoise population. Shifting cultivation is the major threat for its survival other than illegal trade. In situ conservation through establishment of publicly and/or privately owned nature reserves is recommended.

Journal of East African Natural History Vol. 92 (1&2) 2003: pp. 81-96