Unless a safe refuge is found where predation threats are negligible, resting poses risks for many animals, necessitating risk management strategies. The adult cowtail stingray (Pastinachus sephen) of Shark Bay, Western Australia, is a solitarily foraging animal that facultatively groups when...

Reproductive skew theory seeks to integrate social and ecological factors thought to influence the division of reproduction among group-living animals. However, most reproductive skew models only examine interactions between individuals of the same sex. Here, we suggest that females can...

Cooperatively breeding groups include individuals that give up some current reproductive opportunities while remaining in a group. In some cases, these individuals are physiologically or morphologically unable to reproduce. Empirical and theoretical evidence suggest that this inability often...

Lekking males are thought to face strong directional selection on secondary sexual traits. How variation in male traits can persist under these conditions remains problematic (the lek paradox). Here, we present several game-theoretic models that show that avoidance of costly and mobile...

Kleptoparasitism is an important means by which many animals obtain limited resources. The success of kleptoparasitism may be influenced by a number of factors, including competitive differences among individuals and the spatial distribution of prey and hosts. I used ideal free distribution...