Lions, hyenas and mobs (oh my!)

Abstract

Understanding the factors that facilitate the emergence of cooperation among organisms is central to the study of social evolution. Spotted hyenas Crocuta crocuta frequently cooperate to mob lions Panthera leo, approaching the lions as a tightknit group while vocalizing loudly in an attempt to overwhelm them and drive them away. Whereas cooperative mobbing behavior has been well documented in birds and some mammals, to our knowledge it has never been described during interactions between 2 apex predators. Using a 27-year dataset, we characterize lion–hyena encounters, assess rates of mobbing behavior observed during these interactions, and inquire whether mobbing results in successful acquisition of food. Lions and hyenas interacted most often at fresh kills, especially as prey size and the number of hyenas present increased. Possession of food at the beginning of an interaction positively affected retention of that food by each predator species. The presence of male lions increased the probability of an interspecific interaction but decreased the likelihood of hyenas obtaining or retaining possession of the food. Hyena mobbing rates were highest at fresh kills, but lower when adult male lions were present. The occurrence of mobbing was predicted by an increase in the number of hyenas present. Whether or not mobbing resulted in acquisition of food from lions was predicted by an increase in the number of mobs formed by the hyenas present, suggesting that cooperation among hyenas enhances their fitness.

Epidemiology and hypothetical transmission cycles ofTrichinellainfections in the Greater Kruger National Park of South Africa: an example of host-parasite interactions in an environment with minimal human interactions

“…Carnivores like lions and hyaenas are considered apex predators [60] and have a dietary overlap of more than 68% [20,61]. Additionally, within the GKNP, these two predators both prefer the same habitat [61], which may result in encounters where kleptoparasitism by both species frequently occurs [41]. These encounters can prove fatal to individuals of both species although mortality of hyaenas is usually higher [61].…”

Applying Lanchester’s laws to the interspecific competition of coral reef fish

“…The success of the body size-only model is unexpected given the importance often attributed to group size in shaping the outcomes of interspecific competitive interactions (Cooper 1991;Lehmann et al 2017), including those among fish (Foster 1985;Ward et al 2002). One possible explanation for this result is a lack of sufficient variation in the data: with a single exception, the dataset used to compare the 4 models only included encounters of a single fish of 1 species with multiple competitors of another species.…”

“…Dominance hierarchies established by interspecific competition play an essential role in determining community structure and composition (Putman and Wratten 1984). Variables such as body size, sex, territory ownership, and relative numbers influence these hierarchies (Fisler 1977;Cooper 1991;Johnsson et al 1999;Lehmann et al 2017), but their relative importance varies across species, making the search for general underlying principles difficult.…”

Introduction to the special column: communication, cooperation, and cognition in predators

“…Staying in Africa, Lehmann et al (2016) examine the highly sophisticated cooperative defence mechanisms of spotted hyenas. These social breeders use complex vocal communication to mediate their defensive responses to challenges from other species, particularly lions.…”