Stable isotopes reveal trophic segregation by sex and age in the Southern giant petrel in two different foodwebs

FORERO, M; GONZÁLEZ-SOLÍS, J.; HOBSON, K.; DONÁZAR, J.; BERTELLOTTI, M.; BLANCO, G.; BORTOLOTTI, G.

Montevideo, Uruguay

Conferencia; III Internacional Albatros and Petrel Conference; 2004

The southern giant petrel (Macronectes giganteus) is an important scavenger in the South Atlantic Ocean. Although some work has been done to study feeding ecology of this species some aspects of intraspecific variability has not been explored due, in part to the limitations of conventional methodologies.  By measuring stable isotopes of nitrogen (d15N, indicator of diet and trophic level) and carbon (d13C, indicator of foraging habits, inshore vs. offshore), we investigated intraspecific differences in trophic ecology between male and female adults, adults and chicks and with the age, in two different breeding locations north and south of the Antarctic Polar Front.