Pelagic seabirds and the marine environment: foraging patterns of wandering albatrosses in relation to prey availability and distribution

Abstract

The foraging success of pelagic seabirds and where and when they catch prey has been largely unknown until now. We use satellite transmitters in conjunction with recorders measuring feeding times and masses ingested to show that wandering albatrosses (Diomedea exulans) on foraging trips from the nest encountered prey on average every 4.4 h and consumed 2.1 kg of food daily. They travelled up to 3600 km from the nesting colony in search of scarce prey, mostly pelagic squid. These were distributed without relation to underwater topography, and were principally caught during daylight hours in discrete patches widely separated along the foraging route. When foraging inshore, the birds fed on more localized aggregations of squid and fish on the shelf breaks. These results demonstrate that the foraging patterns of large seabirds such as wandering albatrosses, which rely on scarce prey, can help to increase our knowledge of the distribution and availability of poorly known but widespread species of squid.