Baleen hormones increase understanding of bowhead whale reproduction
Wild animals provide a unique challenge for physiologists because they are difficult to capture and monitor in their natural habitats. As a result, scientists are increasingly learning about organisms by extracting steroid hormones out of keratinized tissues. This includes hormones such as testosterone, progesterone, and cortisol that are deposited in feathers, human hair, and reptile claws as these tissues grow. A onetime capture and removal of a single sample can provide a scientist with a record of fluctuating amounts of hormone in the body over the growth period of the collected sample. This technique provides a wealth of information about an animal, including its reproductive history. Development of this method is now underway to monitor the reproduction of one of the largest organisms on earth, the bowhead whale.