Figure 3.

Profiles in stable nitrogen ratios (δ¹⁵N, green) and concentrations of immunoreactive progesterone (black), corticosterone (red) and oestradiol (blue) across the baleen plates of female bowhead whales hunted off west Greenland. Closed circles indicate hormone concentrations above a baseline threshold, while open circles indicate hormone concentrations within baseline levels. Dark grey box highlights gestation as defined under hypothesis 2; light grey box extends gestation as defined under hypothesis 1.