Data from: Mind the wind: microclimate effects on incubation effort of an arctic seabird

The energetic costs of reproduction in birds strongly depend on the
climate experienced during incubation. Climate change and increasing
frequency of extreme weather events may severely affect these costs,
especially for species incubating in extreme environments. In this 3-year
study, we used an experimental approach to investigate the effects of
microclimate and nest shelter on the incubation effort of female common
eiders (Somateria mollissima) in a wild Arctic population. We added
artificial shelters to a random selection of nesting females, and compared
incubation effort, measured as body mass loss during incubation, between
females with and without shelter. Nonsheltered females had a higher
incubation effort than females with artificial shelters. In nonsheltered
females, higher wind speeds increased the incubation effort, while
artificially sheltered females experienced no effect of wind. Although
increasing ambient temperatures tended to decrease incubation effort, this
effect was negligible in the absence of wind. Humidity had no marked
effect on incubation effort. This study clearly displays the direct effect
of a climatic variable on an important aspect of avian life-history. By
showing that increasing wind speed counteracts the energetic benefits of a
rising ambient temperature, we were able to demonstrate that a climatic
variable other than temperature may also affect wild populations and need
to be taken into account when predicting the effects of climate change.