Reassessing the Function of Starling Murmurations:A Socially Selected, Costly Cohesion Hypothesis

Murmurations of the European starling (Sturnus vulgaris) represent one of the most elaborate collective behaviors observed in vertebrates. The prevailing explanation attributes murmurations primarily to predator avoidance via confusion and dilution effects (Pitcher & Parrish, 1993; Handegard et al., 2012). While this interpretation has empirical and modeling support, it fails to account for the energetic cost, conspicuousness, temporal regularity, and persistence of murmurations—features that are inconsistent with survival-optimized anti-predator strategies. Here, we argue that murmurations are better understood as a socially selected, costly collective behavior that functions to reinforce social cohesion, group integration, and collective stability in a cognitively sophisticated species. We propose that murmurations persist despite increased energetic expenditure and predation risk, analogous to other costly social and sexual displays (Zahavi, 1975; Andersson, 1994), because their social benefits outweigh survival costs. This framework reframes murmurations as an evolved group-level ritual rather than a defensive response and generates distinct, testable predictions.