A community of Indo-Pacific bottlenose dolphins (Tursiops sp.) in Shark Bay, Western Australia, made up of approximately 41-54 animals, are known to use conical sponges (Echinodictyum mesenterinum) as tools while foraging. This behaviour, termed "sponging", occurs when a dolphin breaks off a sponge and wears it over its rostrum while foraging on the seafloor. Sponging behaviour typically begins in the second year of life. During sponging, dolphins mainly target fish that lack swim bladders and burrow in the substrate. Therefore, the sponge may be used to protect their rostrums as they forage in a niche where echolocation and vision are less effective hunting techniques. Dolphins tend to carry the same sponge for multiple surfacings but sometimes change sponges. Spongers typically are more solitary, take deeper dives, and spend more time foraging than non-spongers. Despite these costs, spongers have similar calving success to non-spongers.
