Orphans' tales: seasonal dietary changes in elephants from Tsavo National Park, Kenya

The similarity of delta(13)C and delta(15)N patterns in hairs of different individuals from the Tsavo East orphaned elephant herd indicates that a single hair represents the dietary preferences and behavior of the entire group. Multiple tail hairs from the same individual collected at different times allows a chronology to be established because of the overlap in isotope patterns in hair, and there is a very high correlation between hair from different individuals in the same group. Forward modeling using a three-component isotope turnover model for hair allows a precise estimate of diet of these elephants over a 2-year interval. Elephants from Tsavo East National Park in Kenya feed predominantly on C-3 leaves, although they have a significant fraction Of C-4 grass in their diet for a short time at the beginning of the rainy season. The overall integrated diet for the elephants studied is between 10% and 15% C-4 grass, although it reaches up to 60% for short intervals. Stable carbon isotope analyses of elephant tooth enamel show that the average integrated dietary preference of elephants in Tsavo National Park remained less than 25% grass between 1940 and the present. (C) 2004 Elsevier B.V. All rights reserved.