The western gray whale recently set the new world record as the mammal with the longest known migration, according to a study published by the academic journal Biology Letters.
The researcher behind the study, Bruce Mate of Oregon State University, found that a female western gray whale swam a total of 13,988 miles - from Russia to Mexico and back - in 172 days.
That migration also raises questions about the whale's status as a critically-endangered species, suggesting that the 180 known western gray whales may be the same species as the eastern gray whale, which has a population estimated at 20,000.
Here & Now's Jeremy Hobson speaks with Mate to learn what else the study has uncovered.
This segment aired on April 15, 2015.