Varvara, a western gray whale, swam from Russia to Mexico and back, for a total of nearly 14,000 miles, in 172 days.
The western gray whale now holds the record as the mammal with the longest known migration, researchers say.
Until now, the title of the longest-migrating mammal belonged to the humpback whale (Megaptera novaeangliae), which migrates up to 10,190 miles (16,400 km) round trip as it travels between its breeding grounds near the equator and the food-rich waters of the Arctic and Antarctic, according to Guinness World Records.
Click here to read a news article about Varvara’s record swim.