Ocean climate variability links incubation behaviour and fitness in Ancient Murrelets ( Synthliboramphus antiquus).

Large-scale interannual and decadal variation in ocean conditions, including sea-surface temperature (SST) has been shown to affect the breeding behaviour of marine birds in the North Pacific. However, as individual species respond differently to changing food supplies, our understanding of the role of climate variation in seabirds is limited. To examine the effect of ocean conditions on breeding behaviour, we measured incubation shift lengths of Ancient Murrelet ( (Gmelin, 1789)), a small marine bird with exceptionally long incubation shift length, in seven, nonconsecutive years. We compared variation in shift length with interyear variation in regional SST. Incubation shifts were longer in years when March-May SST was higher. In years with longer shift length, birds have lower reproductive success. Our results suggested that Ancient Murrelets on Haida Gwaii can adjust their incubation patterns by extending their shift length in relation to SST fluctuations during breeding season. [ABSTRACT FROM AUTHOR]