Output of the best model fitted using REML estimation and standardized variables.

<p>Output of the best model fitted using REML estimation and standardized variables.</p

Forward model selection procedure for the random effect structure.

<p>All models had the same fixed effects structure and were fitted with REML estimation. The fit of each successively more complex model was assessed using likelihood ratio tests. In models 4 and 5, random slopes per individual were modeled in addition to the random intercepts. LR refers to log-likelihood ratio test statistics.</p

Map of the study area indicating the colony location (star), the foraging area of Adélie penguins (in red) and the location of giant icebergs.

<p>The satellite images are from <a href="http://lance-modis.eosdis.nasa.gov" target="_blank">http://lance-modis.eosdis.nasa.gov</a> and illustrate A: a typical iceberg year (Dec. 21, 2004), B: a typical non-iceberg year (Dec. 21, 2008). The foraging area was determined as the polygon that contained 95% of at-sea positions of provisioning parents as determined by radio and satellite telemetry from 1997/1998 to 2008/2009.</p

Backward model selection procedure for the fixed effect structure.

<p>All models had the same random effects structure (ID and year as random intercepts) and were fitted with ML estimation. The full model (Model 3) included the following variables as fixed effects: SIC, SIC², sex, Mark, TSM, BERG, Day, BERG : SIC, BERG : SIC². The fit of each successively less complex model was assessed using likelihood ratio tests. LR refers to log-likelihood ratio test statistics.</p

Estimated growth rates.

<p>Average daily growth rate estimates (with 95% CI) from best model (i.e., model with lowest AIC_c) 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.</p

Growth model parameter estimates.

<p>Parameter estimates (with 95% CI) for the sex effect on growth from the best model (i.e., lowest AIC_c) 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.</p

Measurement diagram.

<p>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.</p

Appendix A. A table showing GLS (geolocation sensor) deployment and retrieval dates, locations, and sample sizes.

A table showing GLS (geolocation sensor) deployment and retrieval dates, locations, and sample sizes

Appendix B. A figure showing GLS-derived penguin locations and sea ice concentration and extent, 2003–2005.

A figure showing GLS-derived penguin locations and sea ice concentration and extent, 2003–2005

Appendix D. Foraging efficiency over time.

Foraging efficiency over time