One or many? Exploring the population groups of the largest animal on Earth

Hunted nearly to extinction during 20th century whaling, the Antarctic blue whale, the world's largest animal, went from a population size of roughly 200,000 to little more than 300. The most recent estimate in 2004 put Antarctic blue whales at less than 1% of their pre-whaling levels. A new study shows that, though these whales feed in different ocean basins, they appear to be a single population, information that will help conservation efforts moving forward.