At a whopping 14,000 miles, whale wins the longest mammal migration

With a 14,000-mile trek from Russia to Mexico and back, a nine-year-old western North Pacific gray whale named Varvara, blows all other migratory mammals out of the water.

A report published in Biology Letters by researchers in Russia and the Pacific Northwest, captured her 172-day journey.

While the annual migration of eastern gray whales to the Californian coast is well documented, researchers didn't know that the smaller, critically endangered North Pacific gray whale species joined them for the ride. Varvara's journey raises speculation that the two species may be more interconnected than previously thought.

Western North Pacific gray whales like Varvara were once thought to be extinct. Today, researchers believe the population to be around 130, but the their migratory and reproductive patterns are largely unknown. For the study, satellite tags were attached to seven western North Pacific gray whales, including Varvara, whose name is the Russian equivalent of 'Barbara.' 

To their surprise, researchers found the Western gray whales migrated to breeding grounds of the non-endangered eastern gray whales.

Of the seven, Varvara's journey was the farthest. Beginning in November 2011, Varvara swam from Sakhalin Island, Russia, an annual feeding ground, to Cabo San Lucas, Baja California. 

“She crossed the Bering Sea, the Gulf of Alaska [and swam] the length of the North American continent to get down to the Baja breeding calf lagoons that are used by eastern North Pacific animals,” Bruce Mate, the director of the Marine Mammal Institute at Oregon State University, told CBS News.

While not as critically endangered as their western cousins, eastern gray whales have also had a tumultuous past, nearing extinction multiple times before becoming a protected animal in the 1940s. In 1995, the species was removed from the endangered species list, though it remains protected. Currently, there are about 20,000 eastern gray whales in the Pacific Ocean.

Since whales often follow the migration patterns of their mothers, this new study raises questions about whether the western gray whale is indeed its own variety or simply an extension of its eastern cousin. Or, were the seven tagged western whales simply eastern whales that migrated all the way to Russia, and western whales are truly extinct? Genetic sampling may reveal that they are one and the same, but Dr. Mate said more research needs to be done.

“It's a question that still needs to be addressed,” Mate told CBS.

Regardless, Varvara's trek was impressive, to say the least. She beat the previous record for longest mammal migration, held by a humpback whale that travelled 11,706-miles round-trip in 2011, by a few thousand miles. Mate also said they were surprised at the navigational techniques Varvara used to find her way. Before the study, the whales were thought to rely mostly on following coastlines or the first route shown to them by their mothers. Varvara seemed to be free-styling during parts of her journey, often venturing into deep waters away from the coast.

“Needless to say, we’re impressed," Mate told The Washington Post. "How she did it remains to be seen.”