Fig 1.
Schematic illustrating the location of morphological measurements collected from male and female Adélie Penguin chicks during Austral summers of 2012–13 and 2013–14 on Ross Island, Antarctica. Bill was measured to the nearest hundredth mm and remaining measurements to the nearest mm. Dashed line indicates humeral head on underside of the flipper.
Table 1.
Growth model parameter estimates.
Parameter estimates (with 95% CI) for the sex effect on growth from the best model (i.e., lowest AICc) for each morphological measurement of Adélie Penguin chicks during 2012–13 and 2013–14 on Ross Island, Antarctica. Plus signs denote additive effects and asterisks denote interactions. Sex was not supported as an important factor associated with foot growth.
Table 2.
Average daily growth rate estimates (with 95% CI) from best model (i.e., model with lowest AICc) relating growth rates of morphological characteristics and mass to sex, year, brood size, chick hatching order; and sample sizes (n) for male and female Adélie Penguin chicks measured, and weighed during 2012–13 (2012) and 2013–14 (2013) on Ross Island, Antarctica. Sex was not supported as an important variable for foot growth so only means by year (best model results) are reported.
Fig 2.
Estimated average growth rates (with 95% CI) for mass, and length of bill, flipper and tibiotarsus for male and female Adélie Penguin chicks during 2012–13 (2012) and 2013–14 (2013) on Ross Island, Antarctica. Estimates calculated for mean values for other important variables in best model for each measurement (see text for details). Note different units and scales for y axes. Foot growth is not shown due to lack of support for an effect of sex.
Fig 3.
Sex-based differences in diet type.
Estimated mean values for δ 15N (with 95% CI) for male and female Adélie Penguin chicks during 2012–13 and 2013–14 on Ross Island, Antarctica. δ 15N is a proxy for the proportion of fish in the diet.