Albatross cam for bird's eye view
Saturday, October 17 2009 @ 04:17 PM EDT
Contributed by: richardpitt
Small cameras strapped to four albatrosses in the southern Atlantic Ocean have shed light on the birds' feeding patterns.
Still pictures from the cameras show the birds foraging in groups before returning to feed their chicks.
The albatrosses were also seen to hunt alongside killer whales, an approach likely adopted because the whales drive prey fish toward the surface.
The research is published in the open-access journal PLoS ONE.
From the PLos ONE journal:
Killer whales occur regularly over the continental shelf around South Georgia . The species feeds on a wide range of prey, such as other whales, pinnipeds and penguins, but they are also known to feed on Patagonian toothfish, Dissostichus eleginoides, by stripping them from longline fisheries . Black-browed albatrosses feed mainly on squid, fish and krill (reviewed in Xavier et al. ), but the deep-water toothfish constitutes an important component of their diet in some breeding localities . Patagonian toothfish or other deep-water fish that occur in their diet  could be available to shallow-diving black-browed albatrosses only through an interaction with deep-diving predators (from their food scraps) or with commercial fisheries (from offal or bycatch items). When killer whales feed on fish, fragments of prey are often left near the sea surface . These prey fragments could be an important food resource for albatrosses. Scavenging on such prey fragments may be more energetically advantageous than the pursuit and capture of live prey, as such activities can require frequent take-off, landing, and prey handling which may all be energetically costly . Targeting the less-mobile prey fragments may also reduce the number of plunge dives needed to capture a prey item. Therefore, a close association with foraging killer whales would help albatrosses to find food more efficiently in the apparently ‘featureless’ sea, especially in a year when the availability of aggregative prey species (such as Antarctic krill in South Georgia) is low . Such interactions may be quite common and may account for the presence of other prey species such as lamprey Geotria australis, parasitizing to their host, Patagonian toothfish , in the diet of the closely related grey-headed albatrosses, Thalassarche chrysostoma .