Scale-dependent feedback between sociality and space use in a long-lived marine predator

Abstract

Spatial and social behaviours in animals are intertwined, yet the causal direction of this feedback--and how it varies across scales--remains largely unresolved. Using long-term data from false killer whales (Pseudorca crassidens) in the main Hawaiian Islands, we developed and applied a scale-explicit analytical framework to test how social reliance and resource ephemerality govern top-down versus bottom-up processes linking movement and sociality. Movements, association networks, genetic relatedness, and isotopic niches reveal that strong social bonds drive bottom-up emergence of short-term intra-group movements, while ephemeral and likely island-associated prey landscapes impose top-down constraints on inter-group dynamics across scales. These complementary processes generate persistent, fine-scale fidelity within some groups and relatively well-differentiated feeding niches among them. Our findings highlight a general mechanism by which life-history strategies and environmental stochasticity jointly determine the scale and direction of feedback between space use and sociality--shaping population structure and connectivity in mobile social predators.