Abstract:
Animals are faced with a variety of dangers or threats, which are increasing
in frequency with ongoing environmental change. While our understanding
of fearfulness of such dangers is growing in the context of predation and
parasitism risk, the extent to which non-trophic, interspecific dangers elicit
fear in animals remains less appreciated. We provide an experimental test
for fear responses of savannah ungulates to a dominant and aggressive
megaherbivore, the African bush elephant (Loxodonta africana), and contrast
responses to an apex predator known to elicit fear in this system. Using an
automated behavioural response system, we contrast vigilance and run
responses of ungulates to elephant, leopard (Panthera pardus), and control
(red-chested cuckoo Cuculus solitarius) vocalizations. Overall, we find that
ungulates responded to elephant calls, both in terms of an increase in run
and vigilance responses relative to controls. The magnitude of most behavioural
responses (four of six considered) to elephant vocalizations were not
significantly different than responses to leopards. These results suggest that
megaherbivores can elicit strong non-trophic fear responses by ungulates
and call to broaden frameworks on fear to consider dominant species,
such as megaherbivores, as key modifiers of fear-induced interactions.
