Cold comfort:Arctic seabirds find refugia from climate change and potential competition in marginal ice zones and fjords

• Published in: Ambio
• Main Authors: Bonnet-Lebrun, Anne-Sophie, Larsen, Thomas, Thórarinsson, Thorkell Lindberg, Kolbeinsson, Yann, Frederiksen, Morten, Morley, Tim I, Fox, Derren, Boutet, Aude, le Bouard, Fabrice, Deville, Tanguy, Hansen, Erpur Snær, Hansen, Thomas, Roberts, Patrick, Ratcliffe, Norman
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2022
• Subjects: Climate change; Competition; Fjords; Niche partitioning; Refugia; Sea ice; Estuaries; Charadriiformes; Ice; Ice Cover; Animals; Arctic Regions; Ecosystem; Refugium; Arctic; Iceland; Uria aalge; Uria lomvia; uria
• Online Access: https://pure.au.dk/portal/da/publications/cold-comfort(868b4550-bf84-4561-9b2a-190c46d25fcf).html; https://doi.org/10.1007/s13280-021-01650-7; https://pure.au.dk/ws/files/333612589/s13280_021_01650_7.pdf

Climate change alters species distributions by shifting their fundamental niche in space through time. Such effects may be exacerbated by increased inter-specific competition if climate alters species dominance where competitor ranges overlap. This study used census data, telemetry and stable isotopes to examine the population and foraging ecology of a pair of Arctic and temperate congeners across an extensive zone of sympatry in Iceland, where sea temperatures varied substantially. The abundance of Arctic Brunnich's guillemot Uria lomvia declined with sea temperature. Accessibility of refugia in cold water currents or fjords helped support higher numbers and reduce rates of population decline. Competition with temperate Common guillemots Uria aalge did not affect abundance, but similarities in foraging ecology were sufficient to cause competition when resources are limiting. Continued warming is likely to lead to further declines of Brunnich's guillemot, with implications for conservation status and ecosystem services.