Using a simplified field progestagen method to assess ovarian activity in female African elephants

Abstract

Non-invasive endocrine monitoring is an important conservation tool frequently used to support the management of wildlife species. Investigating ovarian activity and pregnancy rates of free-ranging African elephants can enhance our knowledge about the physiology of this highly social and long-lived species. The utility of a new, field-friendly progestagen enzymeimmunoassay (EIA) method was tested by monitoring ovarian activity of 40 females in Addo Elephant National Park (AENP), South Africa. Fecal samples were collected opportunistically from known individuals (June 2007–September 2009) and fecal progestagen metabolites (FPM) were extracted in the field and analyzed on-site using a visual, qualitative EIA. Those results were compared to the laboratory quantitative EIA assessment of hormone concentrations in the U.S. Qualitative FPM concentrations were strongly correlated with quantitative concentrations ( r s = 0.72). Fecal samples collected from pregnant elephants ( n = 22) had significantly higher FPM concentrations than non-pregnant individuals, and month of gestation was the strongest predictor of FPM concentrations. Endocrine profiles suggested that five older females were no longer cycling normally. Simplified field endocrine techniques could transform endangered species research under field conditions and provide reliable and economical new tools for making sensible conservation management decisions based on real-time hormone results.