Fecal glucocorticoid metabolite analysis as an indicator of stress during translocation and acclimation in an endangered large mammal, the Grevy's zebra

Fecal glucocorticoid metabolite (FGM) analysis provides a non-invasive method for studying the physiological response of wildlife to a variety of stressors and is a ground-breaking monitoring technique in wildlife management and conservation. The conservation benefits of successful wildlife translocation restocking efforts are significant but understandably stressful for the animals being captured, removed from familiar habitat, held in captivity in many cases and subsequently released into an unfamiliar environment. It is imperative that we identify non-invasive methods for evaluating stress in translocated animals, especially in endangered species. Twenty Grevy's zebra Equus grevyi were translocated to Meru National Park as part of a Kenya Wildlife Service re-population initiative. FGMs were monitored from the time of capture, during captivity and post-release as an indicator of the stress of translocation and acclimation to the new environment. FGMs from representative non-translocated zebra were used as a further control. When held in pens at Meru Park 3-4 and 5-6 weeks after capture, the zebra had higher FGMs (25.1±1.2 and 23.4±1.3 ng g⁻¹) than either at the time of capture (14.6±2.1 ng g⁻¹) or non-translocated controls (16.2±1.2 ng g⁻¹). This suggests that the stress of captivity elevated FGMs. FGM concentrations returned to pre-capture concentrations c. 11-18 weeks after the zebra were released into Meru Park. The return of FGM concentrations to baseline suggests successful acclimation to the new environment. This study supports the use of FGM analysis as an assessment technique in wildlife management projects involving the movement of endangered large mammals with application for monitoring stress in a wide array of conservation projects involving translocation, reintroduction and rehabilitation.