Female dolphins remember who is aggressive when choosing a mating partner, research shows

The researchers collected 34 signature whistles from male dolphins and played them underwater to 17 female dolphins, using drones to observe their responses. Photograph: Stephanie King View image in fullscreen The researchers collected 34 signature whistles from male dolphins and played them underwater to 17 female dolphins, using drones to observe their responses. Photograph: Stephanie King Female dolphins remember who is aggressive when choosing a mating partner, research shows Researchers observed unavailable female dolphins – those that were older, or with calves – did not show the same avoidant behaviour Get our breaking news email , free app or daily news podcast Female dolphins identify males by their unique calls and keep track of their past behaviour, choosing to avoid the most aggressive males during mating season, new research suggests. Bottlenose dolphin society is complex, and male and female dolphins often know each other for decades, said Prof Stephanie King, an expert in animal behaviour at the University of Bristol. These relationships could be positive, she said. Males might perform displays to impress the females, or engage in affiliative behaviours like touching or petting, a bit like holding hands in humans. But during mating season, the males often worked together – in pairs or trios, and larger alliances – to gain access to females by aggressively herding them into “consortships”, mating events that could last anywhere from hours to weeks. By a bottlenose: hundreds of citizen scientists join NSW’s first dolphin census Read more King said the male dolphins would “work together to keep her with them for as long as possible,” adding that sometimes they could be “quite coercive”. “They’ll restrict the female’s movements. They’ll want to keep the females in the areas that they prefer, because then they’re near other males that can help them defend that female from rivals.” Sign up for the Breaking News Australia email Female dolphins likely observed these behaviours over time, and avoided the more aggressive males, according to research published in the Proceedings of the National Academy of Sciences. Consortships could involve biting, hitting or charging – interactions that were costly to females who not only risked physical injury but also lost crucial foraging time, the paper said. Some males engaged in the aggressive behaviour more often than others. “We now know that males and females can use signature whistles to track individual behaviour over time and use that to inform decision making,” King, an author of the paper, said. View image in fullscreen The study showed unavailable females, including those with a calf, did not react as strongly as reproductively available ones. Photograph: Stephanie King The research involved a population of Indo-Pacific bottlenose dolphins from Shark Bay in Western Australia that have been studied in depth for more than 40 years – providing rich insights into their lives. This includes each m