Killer whales build complex social relationships, they know how to be friends with individuals of the same sex and age.
In a study by the University of Exeter and the Center for Whale Research (CWR), the authors used a drone to study how killer whales socialize.
Based on 40 years of data collected by the CWR on southern killer whales, the authors note that these animals are endangered in the Pacific Ocean.
The results show that killer whales spend more time interacting with certain individuals in their flock and tend to prefer friends of the same sex and the same age. The authors also looked at cases where whales have surfaced together, as acting in unison is a sign of social bonds in many species.
Another feature of behavior in society was tactile contacts: the authors compared their number with the interactions of two close people. In many species, including humans, physical contact tends to help calm and relieve stress.
The study also found that whales become less socially active as they age.