Pregnancy events from earplugs
Amazingly, we can extract progesterone, the pregnancy hormone, from individual layers in the earplug. The progesterone is averaged over the entire layer, which corresponds to 6 months of time. Because it is a 6 month average, I have decided to look at the percent change in progesterone from the preceding point. This is because progesterone increases quickly after conception, remaining high until birth.
For every female baleen whale for which I have progesterone data, I have determined how many pregnancies they have had, their age at first pregnancy, pregnancy intervals, and pregnancy rate. This also allows me to model population dynamics and investigate reproductive senescence and population trends in four species of baleen whales.
Status: Revise and resubmit at Communications Biology.