Breeding range translates into staging site choice: Baltic and Arctic Barnacle geese Branta leucopsis use different habitats at a Dutch Wadden Sea Island.

Habitat use of two populations of Barnacle Goose Branta leucopsis, one arctic and one temperate breeding, was studied on Schiermonnikoog, an island in the Dutch Wadden Sea, during winter and spring 1988/89. Although both populations have overlapping winter ranges, habitat choice on a smaller scale differed in late winter and spring. Birds from the large arctic population mainly used feeding grounds situated on an ungrazed natural saltmarsh, especially during spring, whereas birds belonging to the recently established temperate Baltic population continued to use cattle-grazed, heavily fertilised pastures and adjacent semi-natural cattle-grazed saltmarsh vegetation throughout the staging period. Barnacle Goose grazing pressure on the fertilised grasslands increased dramatically during the last two decades, but only little on the saltmarsh. Vegetation on improved pastures was of higher quality, measured in terms of nitrogen content, than vegetation on the ungrazed natural saltmarsh. Surprisingly, there was only a weak tendency that birds utilising grasslands produced more offspring. Differential energetic and nutritional needs of the two populations or an inability of arctic birds to break with their traditionally established feeding routines are the most likely explanations for the observed pattern

Van Der Jeugd H.P., Olthoff M.P. & Stahl J, ARDEA 89 (2): 253-265.