Lion and Hyena Interactions
Michigan State University
Lions and spotted hyenas are apex predators in African ecosystems. Spotted hyenas compete directly with lions for food; during direct interactions hyenas frequently 'mob' lions to force them to leave their food. Mobbing behavior requires hyenas to act cooperatively. A 'mob' is two or more hyenas acting together to approach and aggress upon one or more lions in an attempt to gain control of a carcass. Mobbing behavior involves great danger for hyenas (Trinkel & Kastberger 2005). In my project I am looking at situations when a hyena or a small group of hyenas stumble upon lions that have food. We have 25 years of archived field notes that will be analyzed. I will determine whether or not the hyena(s) vocalize to attract more hyenas in order to try and steal the food from the lions. We hypothesize that hyenas with lower social rank will not vocalize, because if higher ranking hyenas answer the call, then the lower ranking individual who called would not get to eat. However, if it is a high-ranking hyena who discovers lions with food, they should vocalize because, if food is successfully procured from the lions, high ranking hyenas will be able to eat. Our goal is to characterize cooperation among hyenas during interactions with lions. By understanding mobbing behavior we can better understand both lion and hyena ecology. Hyenas have no theory of mind so understanding mobbing behavior can help us understand what motivates them. If we can better understand what drives cooperation in hyenas, we should be able to design robots that cooperate as well.