Optic flow cues help explain altitude control over sea in freely flying gulls.

ABSTRACT: For studies of how birds control their altitude, seabirds are of particular interest because they forage offshore where the visual environment can be simply modelled by a flat world textured by waves then generating only ventral visual cues. This study suggests that optic flow, i.e. the rate at which the sea moves across the eye's retina, can explain gulls' altitude control over seas. In particular, a new flight model that includes both energy and optical invariants helps explain the gulls' trajectories during offshore takeoff and cruising flight. A linear mixed model applied to 352 flights from 16 individual lesser black backed gulls (Larus fuscus) revealed a statistically significant optic flow set-point of ca 25° s^-1. Thereafter, an optic flow-based flight model

SUBMITTER: Serres JR 

PROVIDER: S-EPMC6833325 | biostudies-literature | 2019 Oct

REPOSITORIES: biostudies-literature