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

详细信息    查看全文

• 作者：Nina Dehnhard ; Katrin Ludynia ; Juan F. Masello ; Christian C. Voigt…
• 关键词：Chlorophyll a ; GPS logger ; Sea surface temperature ; Stable isotope analysis ; Stable isotope mixing model
• 刊名：Polar Biology
• 出版年：2016
• 出版时间：September 2016
• 年：2016
• 卷：39
• 期：9
• 页码：1627-1641
• 全文大小：2,328 KB
• 刊物类别：Biomedical and Life Sciences
• 刊物主题：Life Sciences
  Ecology
  Oceanography
  Microbiology
  Plant Sciences
  Zoology
  
• 出版者：Springer Berlin / Heidelberg
• ISSN：1432-2056
• 卷排序：39

文摘

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.