Fig 1: Diel prey distribution patterns and predator responses.(A) Predators foraging efficiency as bottom-dive cycle duration ratio (BDCr) per ° azimuth, with colour indicating density of observations. BDCr was scaled across the two predator species by minimum and maximum values. (B) Depth of prey (blue) and the corresponding depth of dives (% of total) in Alca torda (violet) versus Uria aalge (green) under daylight versus low light (I.e. dusk, dawn and night; based on nautical light levels). (C) % of total numbers of dives in predators and corresponding numbers of prey aggregations (red) per 15 °s azimuth (binned).