Hairs growing from one end of an elephant give clues as to what went in the other. In collaboration with STE, Dr. Thure Cerling is using tail hair samples collected from immobilized elephants to examine changes in diet, nutrition and water sources. Such variation is revealed by analysing the ratios of carbon, oxygen, nitrogen and hydrogen isotopes present in the elephants' tail hair. By combining these results with data on the individual elephant's movements gathered from GPS collars, we can provide a record of the diet of these elephants (and hence the group they are associating with) have been eating over time and examine dietary changes as they move through their range.

Preliminary results from tail hairs of one individual elephant show a growth rate of tail hair of 0.76mm per day (Cerling, pers. comm.). Analysis of tail hairs from two different females, Aztec and Goya, show a remarkable correlation in peaks of isotopes of carbon and nitrogen suggesting that for the long rains of 2001 and short rains of 2000, these elephants were feeding in the same area. The data also show a dramatic increase in grasses in the diet of the elephants during the short and long rains and enable us to directly calculate the fraction of grass in the diet. This information will be correlated with their movements as recorded by GPS collars to verify where the elephants were at these times. Funding is being sought to continue this study in order to examine dietary changes in a large sample of elephants from which we have collected tail hairs.