Researchers reported that the 9-year-old female whale named Varvara swam from Russia to Mexico and afterwards returned back to Russia, breaking the record of the longest known mammal migration.
So far the record was held by the humpback whale or Megaptera novaeangliae. This whale migrates between the equator, where it has its breeding grounds and waters of Antarctic or Arctic, which have waters rich in food. This means that it travels up to 10,190 miles (16,400 km).
However, the gray whale broke the record by migrating 13,988 miles (22,511 kilometers) in five and a half months. The whale was tracked because scientists wanted to find out more about their unique population and why they prefer the northwestern Pacific waters. Most scientists have encountered gray whales on the coast of California but the two groups are believed to intermingle very seldom.
The whale was observed by scientist at the Marine Mammal Institute of the Oregon State University. The journey of five and a half months (172 days) was not surprising taking into consideration the long distance which the wales had to cross. What is unbelievable is the fact that the mammals did not stop to eat while swimming. Another unique thing about Varavara’s journey was her route cross the open ocean. Most whales keep close to the coast since it is believed that they get their sense of direction from their mothers and that their memory is helped by the coastal landmarks and sonar waves. However Varvara went without coastal landmarks, but she crossed the Bering Sea without any clear nautical reference point.
Contrary to this assumption, detail from Varvara’s journey showed that western and eastern gray whales are different. Bruce Mate, the lead author of the study and director of the Marine Mammal Institute, said:
“The ability of the whales to navigate across open water over tremendously long distances is impressive and suggests that some western gray whales might actually be eastern grays. But that doesn’t mean that there may not be some true western gray whales remaining. If so, then the number of true western gray whales is even smaller than we previously thought.”
Mate added that it was unexpected to see that western gray whales have such a long range and moreover to observe them interact with eastern gray whales. This indicates that although previous studies suggest that the species are genetically different there are still some matters which need to be looked into. Mate also remarked that gray whales are very good navigators after noting that they took different routes in their migration.
Image Source: NBC News