In Shark Bay, Australia, a unique behavior known as 'sponging' has been observed among a subset of bottlenose dolphins. This technique involves dolphins using marine sponges to protect their rostrums while foraging on the seafloor, allowing them to access prey that is otherwise difficult to reach.
Sponging is predominantly practiced by female dolphins and is considered a form of cultural transmission, passed from mother to offspring. This behavior enables dolphins to exploit a niche by targeting bottom-dwelling fish that lack swim bladders and are not detectable through traditional echolocation methods. The use of sponges allows them to probe the substrate without injuring their rostrums, facilitating the capture of these prey species.
Research indicates that sponging is a socially learned behavior, with calves learning the technique from their mothers. This cultural transmission has led to genetic similarities among sponging dolphins, suggesting that social behavior can influence the genetic structure of a population. The practice of sponging highlights the dolphins' adaptability and innovative foraging strategies, contributing to their survival and success in the diverse ecosystem of Shark Bay.