Amino acid nitrogen isotope values of modern and ancient Adélie penguin eggshells from the Ross Sea and Antarctic Peninsula regions

This data set contains measurements of nitrogen (δ15N) stable isotope values of twelve individual amino acids from modern and excavated eggshell of Adélie penguins (Pygoscelis adelidae) from multiple sites around the Antarctic Peninsula and Ross Sea regions of Antarctica. Stable isotope analyses were conducted using a gas chromatograph coupled to a continuous flow stable isotope ratio mass spectrometer. Radiocarbon dates of excavated eggshells were estimated using accelerator Mass Spectrometry (AMS) on bone, feather, and egg membrane tissues from the same ornithogenic layer as the eggshell and were completed at the Rafter Radiocarbon Laboratory and New Zealand (NZA), Beta Analytic, Inc. (Beta). All dates were corrected for the marine carbon reservoir effect and calibrated to calendar years before present (cal years BP) using a ΔR of 750 ± 50 years and the MARINE13 calibration curve in Calib 7.0 (2σ range). This data set indexes each individually analyzed eggshell sample with site (location), latitude, longitude, tissue used from radiocarbon dating, age of the sample, and nitrogen stable isotope values of individual amino acids. Details of the data set and all relevant methods are provided in Michelson et al. 2023 Limnol. Oceanogr. DOI:10.1002/lno.12446