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dc.contributor.authorLorentsen, Svein-Håkon
dc.contributor.authorAnker-Nilssen, Tycho
dc.contributor.authorErikstad, Kjell E
dc.contributor.authorRøv, Nils
dc.coverage.spatialNorway, Norge, Sklinna, Røstnb_NO
dc.identifier.citationMarine Ecology Progress Series 2015, 519:209-220nb_NO
dc.description.abstractCurrent and future climate alterations might impact ecological processes like timing of breeding. We used multivariate linear models to assess the importance of food availability and climate on timing of breeding and hatching brood size of European shags Phalacrocorax aristotelis in 2 colonies, Sklinna (65° N) and Røst (67° N), in the Norwegian Sea over 21 yr (1989 to 2009). Predictor variables were ICES abundance estimates of young saithe Pollachius virens, the staple food of shags in these colonies, the previous winter’s North Atlantic Oscillation index (wNAO), and sea surface and air temperatures. Annual population size was included to control for density-dependent effects. The best model for hatching date explained 15% (Sklinna) and 70% (Røst) of the variation and showed that shags bred earlier when 1 yr old saithe were more abundant. The model for Røst also included 2 yr old saithe and wNAO. The best model for hatching brood size explained 40% (Sklinna) and 48% (Røst) and included a positive effect of population size at both sites. The model for Røst also included a positive effect of 1 yr old saithe. Our study demonstrates that abundance of 1 yr old saithe is a key factor for the breeding performance of shags in both colonies, whereas the climate variables were of less importance. Delayed breeding and low brood size were not associated with a high population of breeders, indicating breeding performance was density-independent and that the positive relationship between breeding numbers and saithe abundance mainly reflected variation in non-breeding among established breeders. KEY WORDS: Phalacrocorax aristotelis · Norwegian Sea · Timing of breeding · Brood size · Pollachius virens · NAOnb_NO
dc.rightsNavngivelse 3.0 Norge*
dc.subjectPhalacrocorax aristotelisnb_NO
dc.subjectNorwegian Seanb_NO
dc.subjectTiming of breedingnb_NO
dc.subjectBrood sizenb_NO
dc.subjectPollachius virensnb_NO
dc.titleForage fish abundance is a predictor of timing of breeding and hatching brood size in a coastal seabirdnb_NO
dc.typeJournal articlenb_NO
dc.typePeer reviewednb_NO
dc.source.journalMarine Ecology Progress Seriesnb_NO
dc.relation.projectNorges forskningsrådnb_NO

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Navngivelse 3.0 Norge
Except where otherwise noted, this item's license is described as Navngivelse 3.0 Norge