A tropical bird in the Artic (The Cormorant paradox)

Seabirds, like all marine endotherms, have to compensate for the extensive cooling effect of water when diving. Alone among them, cormorants (Phalacrocoracidae) have a wettable plumage and are predicted to require disproportionately large amounts of food to balance heat losses. These piscivorous bir...

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Bibliographic Details
Published in:Marine Ecology Progress Series
Main Authors: Gremillet, David, Wilson, Rory P., Wanless, Sarah, Peters, Gerrit
Format: Article in Journal/Newspaper
Language:English
Published: Inter Research 1999
Subjects:
Online Access:https://oceanrep.geomar.de/id/eprint/5470/
https://oceanrep.geomar.de/id/eprint/5470/1/m188p305.pdf
https://doi.org/10.3354/meps188305
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Summary:Seabirds, like all marine endotherms, have to compensate for the extensive cooling effect of water when diving. Alone among them, cormorants (Phalacrocoracidae) have a wettable plumage and are predicted to require disproportionately large amounts of food to balance heat losses. These piscivorous birds are thus thought to have a detrimental impact on fish stocks. However, we show here that even in great cormorants from Greenland, which dive in water at 3 to 7°C, daily food intake is lower than for well-insulated European seabirds. Despite their wettable plumage, cormorants thus appear to manage their energy budgets in a remarkably efficient way. Nevertheless, the specific foraging strategies which enable this performance make cormorants dependent on high prey density areas, a feature that should be taken into account by future management plans.