Summary data sheet containing all stable isotope data (carbon and nitrogen) as well as baleen oestrogen and progesterone metabolite concentrations. A moving average for each was also calculated and is available on the sheet (k=3). Baseline progesterone levels are also listed. Data was obtained by subsampling baleen plates at 1 or 2cm intervals and each subsample was sent for the appropriate analysis to generate data. "Year" references the approximate year during which the particular subsample's baleen was grown.