Effect of feeding management on faecal glucocorticoid metabolite concentrations as a measure of physiological stress in the African Elephant (Loxodonta africana)

Abstract

The African elephant (Loxodonta africana) once roamed freely across most of the African conti-nent but is now confined to smaller tracts of land within reserves, protected areas and captive fa-cilities. As such, these animals experience many natural stressors but increased human contact places significant additional stressors on elephants. Monitoring glucocorticoid metabolite (fGCM) concentrations as a stress-related biomarker in faecal samples makes it possible to examine ani-mal welfare aspects without adding additional stress on elephants. With elephants being mixed feeders, they have a very large variety of plant species which they feed on. By monitoring their feed intake and calculating their daily nutritional intake it is possible to determine where deficiencies in nutrition exist, increasing our understanding of these animals and the appropriate mitigation mechanisms to reduce placing additional stress on them. A reduc-tion in elephant stress will have a positive impact on the management of these animals improving their welfare, especially in captive settings. The current study found no significant interactions between the nutritional values of the assumed diet of the HERD elephants and their respective fGCM concentrations. Therefore, fGCM concen-trations were not affected by the diet of the elephants. Significant differences were observed in fGCM concentrations between the different seasons as well as the sex and age class of the ele-phants. However, the fGCM concentrations of the HERD elephants were comparable to fGCM levels of elephants in other facilities and in the wild. The methods used in this paper can be used in situations where the exact nutritional intake of animals is known and then tested for any significant interactions between the nutritional values in their diet and their glucocorticoid levels. This will give a better understanding of the feeding man-agement required for the animals to improve their overall wellbeing.