Washington, June 8 (ANI): Scientists have discovered that female humpbacks, especially of the same age, form bonds that last year after year.
Individual female humpbacks reunite each summer to feed and swim alongside one another in the Gulf of St Lawrence, off Canada, scientists have found.
Baleen whales, which are the largest of all whales, possess huge baleen plates in their mouths, which they use to filter out small prey such as krill and plankton from the water.
During this study, using photographic identification techniques, scientists have found that the same humpback whales reunite each year. After spending the rest of the year apart migrating and breeding, individual humpbacks somehow find each other again in the open ocean each summer, spending the season feeding together.
The longest recorded friendships lasted six years.
"I was very surprised by the prolonged duration," BBC News quoted Dr Christian Ramp, as saying.
"I was expecting stable associations within one season, not beyond. I was particularly surprised by the fact that only females form these bonds, especially females of similar age."
Forming such friendships clearly benefited the female humpbacks, as those that had the most stable and long-lasting associations gave birth to the most calves.
"Staying together for a prolonged period of time requires a constant effort. That means that they feed together, but likely also rest together. So an individual is adapting its behaviour to another one," adds Ramp.
Scientists, however, are clueless as to how these whales find each other time and again. They do know speculate that humpback whales associating with one another may have made it easier for them to be caught in the past by commercial whalers.
"Maybe the social traits are re-evolving due to rebounding populations, or they are completely different to the ones before, due to changes in the environment."
Details of the discovery are published in the journal Behavioral Ecology and Sociobiology. (ANI)