It is always fun to look at wild animals and see behaviors or interactions that we can relate to. The short answer to the question of whale friendship is that whales do have friends – we don‘t fully understand exactly how or why these relationships form, but we can define friendship as an obvious preference to another individual or individuals that lasts over many years. This preference occurs within pods and between migratory groups that do not see each other for the majority of the year. Friendships are seen in both baleen and toothed whales and are likely mutually beneficial relationships. The social structures and friendships between species varies, and we will look at three examples: orcas (killer whales), sperm whales, and humpback whales.
A study from University of Exeter, University of York, and Center for Whale Research published in 2017 indicates that male orcas significantly benefit from friendships and a stronger social position in their pod. Orca pods are tight-knit groups made of both males and females, often with multiple generations of offspring. This study suggests that the social position of male orcas, but not females, can determine their risk of mortality. Males that are more socially integrated with the pod have a much lower risk of mortality, especially when prey is not as readily available. These males appear to have more access to social information including the location of prey, and they are more likely to receive food from other orcas. Female orcas will share food with their ‘friends‘, or individuals that they are particularly close to. Males who have not integrated are three times more likely to die than males who have a strong position in the pod. For a male orca, it pays to have friends.
A 2015 study from Dalhousie University and University of St. Andrews revealed research from 10 years of tracking sperm whale pods. A sperm whale pod can range in size from 5-20 individuals and is typically made up of females and juveniles. Adult males occasionally join pods for short periods of time, and will sometimes form loose groups with other males. The pods observed spanned up to three generations of females. Different pods met and interacted with other groups of sperm whales periodically throughout the observation period. The study showed that the sperm whales show a preference for certain family members, and for ‘friends‘ in other pods. These friendships lasted for many years despite spending most of their time apart.
Toothed whales like orcas and dolphins are well-known for having complex and close social bonds within their pods. Baleen whales were initially thought to be less social than toothed whales, but research in the late 1990's and early 2000's showed that they also form strong family bonds and friendships. A 2010 study from Behavioral Ecology and Sociobiology saw humpback whales reuniting with the same individuals repeatedly over many years. These reunions also occurred despite the humpbacks spending the majority of their time apart. The humpback friendship pairs observed were exclusively two females of similar ages, and they would spend the summer months together. These friendships are also shown to be beneficial, as female humpbacks who had successful and long-lasting friendship ties gave birth to higher numbers of calves. It is also thought that the ‘friendship feeding‘ improves hunting efficiency and can reduce competition between whales.
There are many examples of these types of ‘friendships‘, and while it is impossible for us to define these social ties and preferences as the same kind of friendship we experience, cetaceans certainly form social bonds and show preference to some individuals over others.