Original investigationTemporal gland secretion in African elephants (Loxodonta africana)

The underlying causes of temporal gland secretion (TGS) in African elephants are not well understood. In order to better understand TGS predisposing factors, we assessed TGS in relation to a suite of intrinsic and environmental variables in free ranging elephants. TGS monitoring was done in fully protected areas of Lake Manyara National Park (LMNP) and Tarangire National Park (TNP) and Manyara Ranch (MR), a semi-protected multiple use area. Using a hierarchical modeling approach that accounted for the nested data structure, we found that TGS was mainly associated with elephant-specific variables. The likelihood of TGS increased with elephant age. Female elephants were more likely to show TGS than male elephants. In larger groups, females were less likely to have TGS, whereas the likelihood for TGS increased with group size in male elephants. This information enhances our understanding of TGS, and its importance as physiological marker.