Assessing herbivores vigilance at waterholes in a landscape of fear in a private game reserve, South Africa

Details

Supervisors

Beaumont Maria ; Van Dyck, Hans

Faculty

Faculté des sciences

Degree label

Master [120] en biologie des organismes et écologie, à finalité approfondie

Abstract

Predation can have many effects on the ecology and evolution of prey species. It can induce morphological or physiological responses but also affect their behavior. With the current climate change and the increase of droughts, herbivore species mainly rely on the remaining water sources. In private reserves, management decisions need to be set up in order to provide enough water for the species to survive and pass the dry season. Thereore, artificial waterholes are created. As they rely on these waterholes, herbivore species are more vulnerable to predation when they drink and these places are dangerous. Therefore, prey species tend to adjust their behaviour to reduce this predation risk and use different anti-predator behaviors such as changes in their activity patterns but also their vigilance. Most of the studies about vigilance behavior are located in large areas in Africa such as large game reserves or National Parks, often in places where the diversity and abundance of predators are high. Yet, little is known about vigilance strategies employ by herbivores at waterholes in a smaller and fenced reserve, with a lower diversity and abundance of predators. Therefore, species may act differently. In this study, I have studied a small community of herbivores comprising seven species and the effect of different factors on their vigilance levels in Campfornis Farm, South Africa. I studied the vigilance differences at the global scale : the interspecific level, but also the vigilance differences at a reduced scale within species : the intraspecific level. Vigilance behaviour was measured as vigilance time and vigilance frequency. Many factors showed an effect on vigilance levels : the sex with males being less vigilant than females, age-classes with juveniles showing a lower vigilance than adults and subadults, group sizes with small groups more vigilant than big groups but single individuals having the highest vigilance, group types with bachelor groups more vigilant than mixed and matriarchal groups, habitat with individuals being more vigilant in a closed area than in an open area and interaction with species being less vigilant with others or not. Vigilance was also affected by predation.