The spotted hyena (Crocuta crocuta) is a highly vocal social carnivore that dominates the African landscape.  In contrast with many other social carnivores, hyenas’ cooperative hunts are achieved through stigmergic coordination, and do not require communication.  Instead, spotted hyenas cooperate with communication most often during intense competitive interactions with lions, usually over a food source such as a fresh kill.  In contrast with hunts, these interactions contain striking bouts of vocal communication, usually culminating in a cooperative rush at the lions present.  We aim to understand how communication facilitates these complex cooperative behaviors and eases the cognitive burden required to achieve them.

            Here we characterize the group behaviors of hyenas and describe the factors that influence hyena success during these competitive interactions.  We incorporate social variables such as rank, sex, age, and vocal activity into a model of which individuals participate in these cooperative activities.           

          We then discuss the vocal and cooperative behaviors that take place at these interactions and the social and cognitive framework that make these behaviors and interactions possible.  Finally, we compare and contrast the social structure, cooperative behaviors and communication of other large carnivores to lend insight into similarities and differences among taxa.   This will provide us with the opportunity to test the generality of hypotheses developed to understand the cooperation, communication, and cognitive abilities of other social carnivores, such as wolves.  We conclude that the study of spotted hyenas can play a vital role in determining the selective pressures governing the evolution of the relationship between cooperation and communication.