Most people know that animals, whales included, tend to travel in groups. But researchers have discovered that humpback whales tend to form actual friendships, even lifelong bonds. According to BBC.com, humpbacks are the first baleen whales known to do so.

According to the article, larger baleen whales like humpbacks were thought to be less social than their predatory counterparts, such as orcas. New research reveals that instead, the humpbacks reunite each year to feed and swim beside one another. Scientists around the world have been studying whale migration patterns for more than 30 years, watching as the same whales return to hang out in the water, despite spending months and many miles apart.

The researchers found that female whales develop the longest-lasting friendships among pods of similar age groups. Such findings are commonplace among other sea mammals, but the article cites researchers expressing surprise to discover the friendships among the baleen whales. The article states, "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." The social networks also help the whales feed more efficiently.

Since whales use sound to communicate, the article speculates that the whales use their songs to recognize one another and reunite each summer.

The article suggests that humpback cliques might have been initially broken up by commercial whaling, an industry that could have preyed upon the easier targets of large groups of whales. Since this practice has been outlawed, the whales are free to band back together.