nerc.ac.uk

Cephalopod prey of the black-browed albatrossDiomedea melanophrys at South Georgia

Rodhouse, Paul G.; Prince, Peter A.. 1993 Cephalopod prey of the black-browed albatrossDiomedea melanophrys at South Georgia. Polar Biology, 13 (6). 373-376. 10.1007/BF01681978

Full text not available from this repository. (Request a copy)

Abstract/Summary

Regurgitations were collected from 41 black-browed albatross adults feeding chicks at Bird Island (54°S 38°W), South Georgia in February 1986. The samples were sorted into recognisable food categories and weighed. Cephalopods were identified by means of the lower beak, or in some cases the gladius, and allometric equations were used to calculate mantle length and wet body weight represented by beaks. The samples contained 35.5%Euphausia superba, 30.9% cephalopods and 27.1% fish, by weight. A total of 21 samples contained recognisable cephalopod remains and 20 contained specimens that could be identified. In all, 50 cephalopod specimens, representing an estimated 6,866 g wet weight, were identified. The diet was dominated in terms of numbers, weight and percent occurrence by the ommastrephid squidMartialia hyadesi, and in most cases the entire squid was present with only partial digestion of the skin and arm armature. The cranchiid squidGaliteuthis glacialis was the only other cephalopod of numerical importance but no soft parts were present suggesting that, although significant in the diet of the adults, this species was not being fed to chicks. One specimen each ofGonatus antarcticus, Chiroteuthis sp.,Histioteuthis sp. B. and the octopodidPareledone polymorpha were also present. The cephalopod composition of the diet corresponded closely with a collection made 10 years earlier. The commonest species in the bird's diet,M. hyadesi, has not been found in net and jig samples at South Georgia although it has been taken from the Antarctic Polar Frontal Zone to the west of the Island. The presence of almost complete, undigested, specimens ofM. hyadesi in the bird's diet indicates that it occurs relatively close to South Georgia.M. hyadesi preys largely on myctophid fishes, which themselves prey on small zooplankters, so a significant component of the black-browed albatross diet depends on a food chain which largely by-passesE. superba.

Item Type: Publication - Article
Digital Object Identifier (DOI): 10.1007/BF01681978
ISSN: 0722-4060
Date made live: 12 Oct 2017 10:03 +0 (UTC)
URI: http://nora.nerc.ac.uk/id/eprint/518046

Actions (login required)

View Item View Item

Document Downloads

Downloads for past 30 days

Downloads per month over past year

More statistics for this item...