Inter-annual variation in provisioning behaviour of Rockhopper Penguins Eudyptes chrysocome chrysocome from Staten Island

ADRIAN CARLOS MIGUEL SCHIAVINI; RAYA REY, A; P TRATHAN,

IBIS

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Heidelberg; Año: 2007 vol. 149 p. 826 - 835

0019-1019

Understanding the relationship between reproductive performance and food availabilityrequires knowledge about many different variables, including such factors as the length ofincubation shifts, provisioning rates and patterns, as well as how variability in these factorsaffects reproductive output. To examine some of the most important aspects of parentalinvestment, we studied the provisioning behaviour and patterns of adult Southern RockhopperPenguinsEudyptes chrysocome chrysocomebreeding at Staten Island, Argentina. We investigatedforaging trip duration, provisioning rates and chick survival using adult foraging patterns.Our results show that Rockhopper Penguins had clear sex-specific differences in their provisioningbehaviour. Females provision chicks throughout chick rearing. By contrast, malesprovision chicks only during the crèche stage and at a slightly lower rate than females duringthis period. Foraging trips increased in length as the breeding season progressed. RockhopperPenguins from Staten Island performed longer trips throughout the breeding season thando other species ofEudyptesat several other locations. Our results also show differences inparental investment between years that were related to differences in chick survival. Wesuggest that this was most likely to be related to female rather than male foraging behaviouras only females showed inter-annual differences in their provisioning rates.