Summer feeding strategy of the little auk (Alle alle) from Bjørnøya, Barents Sea

Abstract

Summer food of the little auks nesting on Bjornoya consisted of large copepods, decapod larvae and pelagic amphipods. Food items of 4–6 mm constituted the most common prey size fraction. This prey size range appears to be optimal (most profitable) with regard to the balance between mean individual mass and density of items in the surface layers of the sea. Little auks from Bjørnøya only sporadically take the abundant copepod Calanus finmarchicus (2–3.5 mm in length) but select the much less abundant and larger Calanus glacialis (3–6 mm).RID=""ID="" <E6>Acknowledgements</E6> The authors would like to thank Dr. Monika Normant from the University of Gdansk for her assistance with caloric measurments, and Lech Illiszko and Adam Wajrak for their help with the fieldwork on Bj&oslash;rn&oslash;ya.RID=""ID="" <E5>Correspondence to</E5> J. M. We&cedil;s&lstrok;awski