Data from: Contrasting responses of male and female foraging effort to year-round wind conditions

1. There is growing interest in the effects of wind on wild animals, given
evidence that wind speeds are increasing and becoming more variable in
some regions, particularly at temperate latitudes. Wind may alter movement
patterns or foraging ability, with consequences for energy budgets and,
ultimately, demographic rates. 2. These effects are expected to vary among
individuals due to intrinsic factors such as sex, age or feeding
proficiency. Furthermore, this variation is predicted to become more
marked as wind conditions deteriorate, which may have profound
consequences for population dynamics as the climate changes. However, the
interaction between wind and intrinsic effects has not been
comprehensively tested. 3. In many species, in particular those showing
sexual size dimorphism, males and females vary in foraging performance.
Here, we undertook year-round deployments of data loggers to test for
interactions between sex and wind speed and direction on foraging effort
in adult European shags Phalacrocorax aristotelis, a pursuit-diving
seabird in which males are c. 18% heavier. 4. We found that foraging time
was lower at high wind speeds but higher during easterly (onshore) winds.
Furthermore, there was an interaction between sex and wind conditions on
foraging effort, such that females foraged for longer than males when
winds were of greater strength (9% difference at high wind speeds vs. 1%
at low wind speeds) and when winds were easterly compared with westerly
(7% and 4% difference, respectively). 5. The results supported our
prediction that sex-specific differences in foraging effort would become
more marked as wind conditions worsen. Since foraging time is linked to
demographic rates in this species, our findings are likely to have
important consequences for population dynamics by amplifying sex-specific
differences in survival rates.