A Better Pregnancy Test for Whales

New measurements will help biologists understand a changing ocean.

A large whale is halfway out of the water, about to breach.

It’s not easy to do pregnancy tests on whales. You can’t just ask a wild ocean animal that’s the size of a school bus to pee on a little stick. For decades, the only way scientists could count pregnant females was by sight and best guesses based on visual characteristics. For the last several years, researchers have relied on hormone tests of blubber collected via darts, but the results were often inconclusive (not negative or positive), and researchers couldn’t confidently say if the animal was pregnant or just ovulating.

Research from the National Institute of Standards and Technology (NIST) and Australia’s Griffith University points to a weakness of that testing and provides a new method for hormone testing that offers better results.