New method for testosterone determination in spotted hyenas

In male mammals, testosterone plays a key role in both development and reproduction. Thus, measures of changes in testosterone concentration both within an animal's lifespan and across populations provide information essential for an understanding of growth, reproductive strategies and aging. However, hormone research normally requires the taking of blood samples, which in wild animals is difficult, and not always possible, particularly in protected areas where the capture of wild animals is often prohibited. Additionally, capture and blood sampling may cause stress in wild animals, thereby inducing a change in the hormone concentration being measured. In contrast, the non-invasive monitoring of hormones avoids all these problems. Thus, physiological data of free-ranging animals can be collected easily, thereby allowing repeated sampling from the same animal in its natural environment throughout its lifespan.

Details and verification of the efficacy of the first antibody-based enzyme immunoassay to monitor fecal testosterone metabolites in spotted hyenas are published in PLOS ONE. It is now possible to investigate the influence of age, social status and reproductive behavioural strategies on testosterone concentrations in wild spotted hyenas.