INVESTIGADORES
SCIOSCIA Gabriela
artículos
Título:
Breeding-stage related sex differences in the foraging behaviour of Magellanic Penguins
Autor/es:
ANDREA RAYA REY; KLEMENS PÜTZ; GABRIELA SCIOSCIA; BENNO LÜTHI; ADRIÁN SCHIAVINI
Revista:
EMU
Editorial:
CSIRO PUBLISHING
Referencias:
Año: 2012 vol. 112 p. 90 - 96
ISSN:
0158-4197
Resumen:
Understanding seabird foraging behaviour and its plasticity is vital to establish their role in marine food webs and their use as monitors of change in prey availability. Penguin foraging behaviour is known to differ according to locality, gender, breeding stages and years. In this context, diving behaviour of breeding Magellanic Penguins (Spheniscus magellanicus) was studied during incubation and brooding in the 2003-2004 and 2004-2005 breeding seasons using time-depth recorders at Isla Martillo, Tierra del Fuego, Argentina. Gender-related differences in foraging behaviour were observed during the incubation stage, a period when trip duration was longer than during brooding for both sexes, during both years of study. During the incubation stage females performed longer foraging trips, had lower foraging effort and dove shallower than males in both years. Foraging success was lower for females compared with males only during incubation in 2003. Our results suggest that sex differences, expressed as differences in the foraging parameters of males and females, only develop when sprat (Sprattus fuegensis), the main prey in this locality, is not abundant close to the colony. Females may be extending the volume of water they can exploit by extending trip duration (horizontal distance), while males do it by diving deeper (vertical distance). Our results showed differences in Magellanic Penguin diving capabilities according to sexual dimorphism, but during the study period the differences were only evident for the incubation period.