Title
Plasticity in foraging behaviour and diet buffers effects of inter-annual environmental differences on chick growth and survival in southern rockhopper penguins **Eudyptes chrysocome chrysocome**Plasticity in foraging behaviour and diet buffers effects of inter-annual environmental differences on chick growth and survival in southern rockhopper penguins **Eudyptes chrysocome chrysocome**
Author
Faculty/Department
Faculty of Sciences. Biology
Research group
Behavioural Ecology & Ecophysiology
Publication type
article
Publication
New York,
Subject
Biology
Source (journal)
Polar biology. - New York
Volume/pages
(2016), p. 1-15
ISSN
0722-4060
Carrier
E
Target language
English (eng)
Full text (Publishers DOI)
Affiliation
University of Antwerp
Abstract
In marine ecosystems, primary productivity and consequently food availability for higher trophic levels are often strongly affected by the water temperature. Thus, differences in sea surface temperatures (SST) may lead to differences in the diet composition of predators, but this link is still unknown in many species. By combining GPS tracking and dive analyses on chick-rearing southern rockhopper penguins (Eudyptes chrysocome chrysocome) with stable isotope analyses and monitoring of chick growth rates and chick survival, we here attempted a comprehensive assessment of the effects of inter-annual environmental variability as indicated by SST and chlorophyll a (reflecting primary productivity) data. Inter-annual differences in environmental variables around our study colony on New Island, Falkland/Malvinas Islands, contradicted the general expectation, with higher chlorophyll a concentrations coinciding with higher spring SST in 2010/2011 compared to 2009/2010. Penguins foraged further away from the colony during guard and crèche in 2010/2011 compared to 2009/2010, while performing deeper dives in 2009/2010. Stable isotope mixing models suggested a crustacean-dominated chick diet in 2009/2010, compared to a mixture of squid and fish in 2010/2011. These differences in foraging behaviour and diet, however, had no consequences for chick growth rates or chick survival and thus had no apparent effect on population trajectories. Potentially, environmental conditions in both years could still be seen as favourable compared to other years and breeding sites, enabling the parental birds to buffer the environmental differences by plastic foraging behaviour.
Full text (open access)
https://repository.uantwerpen.be/docman/irua/a7f449/133821.pdf
E-info
https://repository.uantwerpen.be/docman/iruaauth/f1a632/133821.pdf
Handle