Birds in southern Öresund in relation to the wind farm at ... - Vattenfall

ehind the large variation is that few Long-tailed Ducks were encountered in the area in these
years (see above), meaning that a few occasional observations will create rather dramatic
changes in the indices. Note also that no Long-tailed Ducks at all were seen during boat
surveys in 2009-2010, making it impossible to calculate a Jacob’s index for that year. The
pattern that emerges is at least that there was an initial, and complete, avoidance in the first
years of the operational phase (2008-2009). Later years show an ambiguous pattern with
expected use according to the 2010 aerial surveys, complete avoidance during the 2011 aerial
surveys and preference during the 2010-2011 boat surveys. One possible interpretation is that
there is some sort of habituation involved, where birds are more prone to use the wind farm
area when the turbines have been there for a couple of years. The low overall numbers
encountered in the post-construction years do however obscure any form of robust conclusion
The indices from the buffer zone are more straight-forward and these parts seem to be used as
expected (aerial survey data) or preferred (boat survey data) in most years irrespective of the
presence of the wind farm.
We conclude that there was complete initial avoidance of the actual wind farm, but that the
avoidance was of no biological significance as the area in question is of very low value for
Long-tailed Ducks in Öresund and in general.
37