Does supplemental feeding affect behaviour and foraging of critically endangered western giant eland in an ex situ conservation site?

Abstract

The western giant eland (Tragelaphus derbianus derbianus) needs appropriate management for its survival. We measured the effects of supplemental food on activity and browsing patterns during seasons of scarce natural food resources in 2008 and 2009 for a herd of six animals in the Fathala Reserve (Senegal). In response to the provision of high-quality pods of Acacia albida, animals reduced foraging time in 2008 and allocated it to resting. This pattern corresponds to the animals’ behaviour in captivity without foraging versus vigilance trade-offs and with predictable (in time and space) access to food. In 2009, supplemental feeding had no effect on behaviour and was associated with increased foraging and ruminating times than in 2008, suggesting more limited natural food resources in 2009. We recorded high species diversity in the animals’ natural diet. Supplemental food did not induce changes in browsing pattern at the plant species level, probably due to small individual effect on total nutrient and energy intake. Food supplementation, however, facilitates the animals overcoming unfavourable conditions or alleviates stress with additional rest, and could therefore assist as a conservation intervention to enhance fitness.