Foraging in heterogeneous landscapes: variation in movement patterns of a tropical sand-bubbler crab.

This article focuses on the spatio-temporal variation in foraging patterns of the deposit-feeding sand-bubbler crab, *Scopimera intermedia*, on soft sediment shores in Hong Kong. The study found that the crabs forage over larger areas, travel longer distances, and move faster during the hot season compared to the cool season, with these seasonal differences influenced by physiological constraints and conspecific density. At smaller spatial scales, the crabs exhibited flexible, context-dependent movement modes—moving faster and more directionally away from burrows and slowing down with more turning when returning—likely reflecting adaptive responses to the patchy distribution of sediment food. Simulations using composite biased random walk models that incorporated these two movement phases best explained the observed foraging trajectories. These findings highlight the importance of multi-scale environmental factors in shaping foraging strategies and suggest that conservation efforts should consider seasonal and local ecological dynamics affecting *S. intermedia* on intertidal soft shores.