Foraging patterns of polar penguins

Sub-antarctic and polar penguins have revealed important differences in the distances travelled to foraging areas, the physical and biological characteristics of foraging areas, and foraging patterns. Differences are associated with preferred prey and its abundance. Data were acquired using satellite transmitters and time/depth recorders, the former giving location and rates of travel, the latter diving depths and patterns. Distinctions between travel and feeding dives help to assess foraging success. Data were matched to satellite imagery for determination of sea surface conditions. Sub-antarctic penguins travel further than polar penguins, feed near the Antarctic polar front, and are primarily diurnal feeders. Polar species feed at edges of coastal ice, pack ice, and polynyas. Most locations are neritic. Adelies specialise in krill at shallow depth as do sub-polar Macaroni and Royal Penguins. Emperor Penguins target fish in the mesopelagic zone, which is true also of King Penguins feeding at the Antarctic Polar Front. Hunting with 24h of daylight, polar penguins feed continuously with little hourly variation in depth. Subantarctic penguins show considerable diet differences, with reduced feeding at night