Variability in foraging ranges of snow petrels and implications for breeding distribution and use of stomach-oil deposits as proxies for paleoclimate

Snow petrel stomach-oil deposits potentially integrate environmental conditions over greater and more seasonally variable areas than previously assumed, probably with a bias towards conditions in the marginal ice zone (outer pack ice) during the early summer when stomach oil deposition due to nest competition is likely greatest. Our results are consistent with the hypothesis that snow petrel breeding range in the western Weddell Sea is limited by access to foraging habitat, such as coastal polynyas. Although tracking data from other colonies would be useful to confirm the generality of our foraging range estimates, we hypothesise that as sea ice fluctuated over previous glacial-interglacial cycles, this regulated breeding distribution across the region.