Good days, bad days: wind as a driver of foraging success in a flightless seabird, the southern Rockhopper Penguin

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dc.contributor.authorDehnhard, Ninaen_ZA
dc.contributor.authorLudynia, Katrinen_ZA
dc.contributor.authorPoisbleau, Mauden_ZA
dc.contributor.authorDemongin, Laurenten_ZA
dc.contributor.authorQuillfeldt, Petraen_ZA
dc.date.accessioned2015-11-10T14:47:27Z
dc.date.available2015-11-10T14:47:27Z
dc.date.issued2013en_ZA
dc.description.abstractDue to their restricted foraging range, flightless seabirds are ideal models to study the short-term variability in foraging success in response to environmentally driven food availability. Wind can be a driver of upwelling and food abundance in marine ecosystems such as the Southern Ocean, where wind regime changes due to global warming may have important ecological consequences. Southern rockhopper penguins ( Eudyptes chrysocome ) have undergone a dramatic population decline in the past decades, potentially due to changing environmental conditions. We used a weighbridge system to record daily foraging mass gain (the difference in mean mass of adults leaving the colony in the morning and returning to the colony in the evening) of adult penguins during the chick rearing in two breeding seasons. We related the day-to-day variability in foraging mass gain to ocean wind conditions (wind direction and wind speed) and tested for a relationship between wind speed and sea surface temperature anomaly (SSTA). Foraging mass gain was highly variable among days, but did not differ between breeding seasons, chick rearing stages (guard and crèche) and sexes. It was strongly correlated between males and females, indicating synchronous changes among days. There was a significant interaction of wind direction and wind speed on daily foraging mass gain. Foraging mass gain was highest under moderate to strong winds from westerly directions and under weak winds from easterly directions, while decreasing under stronger easterly winds and storm conditions. Ocean wind speed showed a negative correlation with daily SSTA, suggesting that winds particularly from westerly directions might enhance upwelling and consequently the prey availability in the penguins' foraging areas. Our data emphasize the importance of small-scale, wind-induced patterns in prey availability on foraging success, a widely neglected aspect in seabird foraging studies, which might become more important with increasing changes in climatic variability.en_ZA
dc.identifier.apacitationDehnhard, N., Ludynia, K., Poisbleau, M., Demongin, L., & Quillfeldt, P. (2013). Good days, bad days: wind as a driver of foraging success in a flightless seabird, the southern Rockhopper Penguin. <i>PLoS One</i>, http://hdl.handle.net/11427/14827en_ZA
dc.identifier.chicagocitationDehnhard, Nina, Katrin Ludynia, Maud Poisbleau, Laurent Demongin, and Petra Quillfeldt "Good days, bad days: wind as a driver of foraging success in a flightless seabird, the southern Rockhopper Penguin." <i>PLoS One</i> (2013) http://hdl.handle.net/11427/14827en_ZA
dc.identifier.citationDehnhard, N., Ludynia, K., Poisbleau, M., Demongin, L., & Quillfeldt, P. (2013). Good days, bad days: wind as a driver of foraging success in a flightless seabird, the southern Rockhopper Penguin. e79487. doi:10.1371/journal.pone.0079487en_ZA
dc.identifier.ris TY - Journal Article AU - Dehnhard, Nina AU - Ludynia, Katrin AU - Poisbleau, Maud AU - Demongin, Laurent AU - Quillfeldt, Petra AB - Due to their restricted foraging range, flightless seabirds are ideal models to study the short-term variability in foraging success in response to environmentally driven food availability. Wind can be a driver of upwelling and food abundance in marine ecosystems such as the Southern Ocean, where wind regime changes due to global warming may have important ecological consequences. Southern rockhopper penguins ( Eudyptes chrysocome ) have undergone a dramatic population decline in the past decades, potentially due to changing environmental conditions. We used a weighbridge system to record daily foraging mass gain (the difference in mean mass of adults leaving the colony in the morning and returning to the colony in the evening) of adult penguins during the chick rearing in two breeding seasons. We related the day-to-day variability in foraging mass gain to ocean wind conditions (wind direction and wind speed) and tested for a relationship between wind speed and sea surface temperature anomaly (SSTA). Foraging mass gain was highly variable among days, but did not differ between breeding seasons, chick rearing stages (guard and crèche) and sexes. It was strongly correlated between males and females, indicating synchronous changes among days. There was a significant interaction of wind direction and wind speed on daily foraging mass gain. Foraging mass gain was highest under moderate to strong winds from westerly directions and under weak winds from easterly directions, while decreasing under stronger easterly winds and storm conditions. Ocean wind speed showed a negative correlation with daily SSTA, suggesting that winds particularly from westerly directions might enhance upwelling and consequently the prey availability in the penguins' foraging areas. Our data emphasize the importance of small-scale, wind-induced patterns in prey availability on foraging success, a widely neglected aspect in seabird foraging studies, which might become more important with increasing changes in climatic variability. DA - 2013 DB - OpenUCT DO - 10.1371/journal.pone.0079487 DP - University of Cape Town J1 - PLoS One LK - https://open.uct.ac.za PB - University of Cape Town PY - 2013 T1 - Good days, bad days: wind as a driver of foraging success in a flightless seabird, the southern Rockhopper Penguin TI - Good days, bad days: wind as a driver of foraging success in a flightless seabird, the southern Rockhopper Penguin UR - http://hdl.handle.net/11427/14827 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/14827
dc.identifier.urihttp://dx.doi.org/10.1371/journal.pone.0079487
dc.identifier.vancouvercitationDehnhard N, Ludynia K, Poisbleau M, Demongin L, Quillfeldt P. Good days, bad days: wind as a driver of foraging success in a flightless seabird, the southern Rockhopper Penguin. PLoS One. 2013; http://hdl.handle.net/11427/14827.en_ZA
dc.language.isoengen_ZA
dc.publisherPublic Library of Scienceen_ZA
dc.publisher.departmentAnimal Demography Unit (ADU)en_ZA
dc.publisher.facultyFaculty of Scienceen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.rightsThis is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.en_ZA
dc.rights.holder© 2013 Dehnhard et alen_ZA
dc.rights.urihttp://creativecommons.org/licenses/by/4.0en_ZA
dc.sourcePLoS Oneen_ZA
dc.source.urihttp://journals.plos.org/plosoneen_ZA
dc.subject.otherWinden_ZA
dc.subject.otherForagingen_ZA
dc.subject.otherPenguinsen_ZA
dc.subject.otherSeabirdsen_ZA
dc.subject.otherBirdsen_ZA
dc.subject.otherAnimal sexual behavioren_ZA
dc.subject.otherOceansen_ZA
dc.subject.otherSeasonsen_ZA
dc.titleGood days, bad days: wind as a driver of foraging success in a flightless seabird, the southern Rockhopper Penguinen_ZA
dc.typeJournal Articleen_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceArticleen_ZA
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