Supplementary diet components of little auk chicks in two contrasting regions on the West Spitsbergen coast

The complete diet composition structure of the most numerous planktivorous sea bird, little auk (Alle alle), in the European Arctic, is still not fully recognized. Although regular constituents of little auk chick diets, the copepods, Calanus glacialis and C. finmarchicus have been previously relati...

Full description

Bibliographic Details
Published in:Polar Biology
Main Authors: Boehnke, Rafał, Gluchowska, Marta, Wojczulanis-Jakubas, Katarzyna, Jakubas, Dariusz, Karnovsky, Nina J., Walkusz, Wojciech, Kwasniewski, Slawomir, Błachowiak-Samołyk, Katarzyna
Format: Text
Language:English
Published: Springer Berlin Heidelberg 2014
Subjects:
Short Note
Arctic
Hornsund
Magdalenefjorden
Svalbard
Svalbard Archipelago
Alle alle
Calanus glacialis
little auk
Magdalenefjord*
Copepods
Spitsbergen
Thysanoessa inermis
Online Access:http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4459656/
https://doi.org/10.1007/s00300-014-1568-9
Description
Summary:The complete diet composition structure of the most numerous planktivorous sea bird, little auk (Alle alle), in the European Arctic, is still not fully recognized. Although regular constituents of little auk chick diets, the copepods, Calanus glacialis and C. finmarchicus have been previously relatively well described, more taxa were frequent ingredients of the bird’s meals. Therefore, the role of the little auks supplementary diet components (SDCs) at two colonies in the Svalbard Archipelago, Hornsund and Magdalenefjorden, in 2007–2009, is a main subject of this comparative study. Because the SDCs often consisted of scarce but large zooplankters, this investigation was focused on biomass as a proxy of the SDCs’ energy input. Although the total biomass of the food delivered to chicks in both colonies was similar, in Magdalenefjorden, the proportion of SDCs was twice that found in Hornsund. The main SDCs in Hornsund were Decapoda larvae (with predominating Pagurus pubescens) and Thysanoessa inermis, whereas the main SDCs in Magdalenefjorden were C. hyperboreus and Apherusa glacialis. Previous investigations, which indicated lipid richness of SDCs, together with our ecological results from the colonies, suggest that this category might play a compensatory role in little auk chick diets. The ability to forage on diverse taxa may help the birds to adapt to ongoing Arctic ecosystem changes.

Similar Items