Meeting Abstract
Animals use diverse feeding strategies to capture and consume prey underwater. Many marine animals exhibit behavioral flexibility when feeding to deal with spatial and temporal heterogeneity in prey resources. However, observations of feeding events underwater are rare, so little is known about the relationship between feeding strategies, kinematic performance, and behavioral flexibility. We documented the feeding behavior and kinematics of the critically endangered Hawaiian monk seal (Neomonachus schauinslandi, n=7) through controlled feeding trials. Seals were fed multiple prey types (e.g., night smelt, capelin, squid, and herring) that varied in size and shape, and we used mixed effects models and multivariate analyses to examine behavioral flexibility in behavior and kinematic performance. Although Hawaiian monk seals have a skull morphology adapted for biting, seals primarily used suction feeding (91% of feeding trials) across all prey types; seals used biting less frequently (9% of feeding trials). Suction feeding was kinematically distinct from biting and characterized by shorter temporal events, a smaller maximum gape, a larger gular depression, and fewer jaw motions compared to biting. Seals showed behavioral flexibility in their use of the strategies; suction feeding was used most frequently when targeting small to medium prey, and biting was used with increasing frequency on large prey. The feeding kinematics differed between strategies and prey types, showing that seals adjusted their kinematics to particular feeding contexts. Hawaiian monk seals are opportunistic and generalist marine predators and their ability to adapt their feeding behaviors and kinematics as found in this study should allow them to target diverse prey resources.
