The importance of play for animals, including humans, has long been recognized. However, the reasons behind this behavior have remained unclear. A new study conducted on male Indo-Pacific bottlenose dolphins in Shark Bay, Western Australia sheds light on why play is crucial for these dolphins.
Play comes with its costs, especially for young animals. It requires energy that could be used for growth and makes them more vulnerable to predators. Despite these drawbacks, play is highly rewarding and enjoyable. The immediate benefits of play, however, may not outweigh the potential costs.
The study reveals that male dolphins who spend more time playing as juveniles end up siring more offspring as adults. This finding highlights the importance of play for these dolphins specifically.
One possible explanation for juvenile play is that it serves as practice for adult behaviors such as mating and fighting. If this is true, it would ultimately enhance an individual’s ability to survive or reproduce as an adult. While some species engage in sexual or combat-like play behaviors, there is limited evidence linking play to long-term reproductive benefits.
The study focused on dolphins in Shark Bay, where lifelong friendships among adult males have been observed. These alliances are formed to find and compete for mates. Juvenile play in this population resembles these adult events, known as consortships. Juveniles take turns playing the roles of “female” and “male” in small groups, mimicking adult mating behaviors.
The researchers examined whether male juvenile play aligns with adult reproductive behaviors and if it is associated with greater success in siring offspring later in adulthood. They observed specific juvenile males over a two-year period, recording their behavior and vocalizations using underwater microphones.
The study found that juvenile males spent more time playing the “male” role than females. Those with strong social bonds, likely to form alliances as adults, were more likely to synchronize their play behavior. This suggests that practicing with future allies is beneficial for males. Juvenile males also produced pops, a vocal signal used by adult males to keep females close. This behavior was similar to that observed during consortships, indicating the need for practice to achieve the adult rhythm.
To determine if spending more time playing as juveniles led to siring more offspring in adulthood, the researchers analyzed past observations of juvenile male play and genetic paternity data. The results showed that males who spent more time playing their future adult roles as juveniles had more offspring as adults.
This study demonstrates that social play is not just for fun but plays a crucial role in the development of male dolphins. It provides them with an opportunity to practice reproductive skills years before they are needed, ultimately increasing their success as adults. Additionally, play helps strengthen friendships that will develop into lifelong alliances. Future research aims to explore whether play also influences the selection of friends among these dolphins.
