INVESTIGADORES
CASAUX Ricardo Jorge
artículos
Título:
New Correction factors for the quantification of fish represented in pellets of the Imperial Cormorant Phalacrocorax atriceps.
Autor/es:
CASAUX R,; BARRERA-ORO E.; FAVERO, M.; SILVA, P.
Revista:
Marine Ornithology
Editorial:
Pacific seabird group
Referencias:
Año: 1998 vol. 26 p. 35 - 39
ISSN:
1018-3337
Resumen:
A
comparative analysis was carried out on stomach contents and pellets (=regurgitated
casts) of the Imperial Cormorant Phalacrocorax
atriceps collected throughout
the breeding season at Nelson Island, South Shetland Islands, Antarctica. This
allowed an estimation of correction factors to compensate for the loss and
digestion of otoliths in pellets and more accurately estimate the real mass of ingested
fish. These factors were calculated for Notothenia
coriiceps, Harpagifer antarcticus,
Nototheniops nudifrons, Trematomus newnesi, Gobionotothen gibberifrons, Notothenia
rossii, Pagothenia bernacchii and Parachaenichthys charcoti, but not for Pleuragramma antarcticum, Notolepis
coatsi and Electrona antarctica since they were only represented in pellets. Fish were the main prey and N. coriiceps and H. antarcticus were the
dominant species both in mass and number. Observations of activity patterns
showed that daily foraging trips per bird increased in number but diminished in
duration through the breeding season. These trends reflected the increase in
the chicks' energetic demands.