Gray Whale Breaks Mammal Migration Record
Using satellite tags, scientists followed a whale's journey across the Pacific Ocean and recorded the longest migration of any mammal
Scientists tracked the journey of a female member of the the western north Pacific gray whale population and found the mammal to make a 22,500km-long (14,000 miles) return trip from Russia's east coast to breeding grounds in Mexico and back within 172 days.
The whale's journey is the longest recorded mammal migration to date, breaking the previous record set by a humpback whale (16,400 km), scientists say.
Until now, it was believed that there were two distinct groups of gray whales - one residing in waters along the west coast of North America and another off the coast of eastern Asia.
While the eastern gray while population bounced back from the brink of extinction, their western cousins have an estimated population of just 130 and are listed as 'critically endangered' species by the International Union for Conservation of Nature (IUCN.
The journey of the whale, nicknamed Varvara, suggests that there the two groups may be interlinked: 'Clearly the experience of Varvara, and Flex before her, demonstrates that western gray whales can and do come over to the eastern Pacific, Bruce Mate, Director of the Marine Mammal Institute of Oregon State University and co-author of the study said.
'Whether this suggests that they are not a distinct population or that we underestimated their range isn’t yet clear.'
The study was published in Biology Letters on 14 April.