Data from: Sex-specific effects of fisheries and climate on the demography of sexually dimorphic seabirds

1. Many animal taxa exhibit sex-specific variation in ecological traits,
such as foraging and distribution. These differences could result in
sex-specific responses to change, but such demographic effects are poorly
understood. 2. Here we test for sex-specific differences in the demography
of northern (NGP, Macronectes halli) and southern (SGP, M. giganteus)
giant petrels - strongly sexually size-dimorphic birds that breed
sympatrically at South Georgia, South Atlantic Ocean. Both species feed at
sea or on carrion on land, but larger males (30% heavier) are more reliant
on terrestrial foraging than the more pelagic females. Using multi-event
mark-recapture models we examine the impacts of long-term changes in
environmental conditions and commercial fishing on annual adult survival
and use two-sex matrix population models to forecast future trends. 3. As
expected, survival of male NGP was positively affected by carrion
availability, but negatively affected by zonal winds. Female survival was
positively affected by meridional winds and El Niño Southern Oscillation
(ENSO), and negatively affected by sea ice concentration and pelagic
longline effort. Survival of SGPs did not differ between sexes; however,
survival of males only was positively correlated with the Southern Annular
Mode (SAM). 4. Two-sex population projections indicate that future
environmental conditions are likely to benefit giant petrels. However, any
potential increase in pelagic longline fisheries could reduce female
survival and population growth. 5. Our study reveals that sex-specific
ecological differences can lead to divergent responses to environmental
drivers (i.e. climate and fisheries). Moreover, because such effects may
not be apparent when all individuals are considered together, ignoring sex
differences could underestimate the relative influence of a changing
environment on demography.