Somewhere in the warm, clear waters off the coast of Australia, a mature bottlenose dolphin is swimming with her daughter. It’s dinnertime. But, instead of chasing down a fish in open waters like she usually does, mom swims over to a basket sponge growing on the ocean floor. In a deft move, she breaks off a piece of the sponge, then fits it snugly over her rostrum — her beak. It’s hard not to wonder what that curious, watchful youngster might be thinking about all this. Are you going to eat that sponge? Are we playing?
With the sponge secured on her beak, the older dolphin starts sweeping her head back and forth across the ocean floor. She’s looking for bottom‐dwelling fish like the sand perch, which hide themselves on the floor of the sea under layers of sand. As for the sponge stuck onto her rostrum, it allows her to clear away the sand without injuring herself on broken chunks of coral, or maybe even suffering the sting of another bottom dweller, the scorpion fish. The extra work it takes to catch a fish like the sand perch is worth it because bottom dwellers tend to be fattier. And for a dolphin, fattier means more nutritious.
Sure enough, after a few minutes, a sand perch flushes. The fish dashes off for a few yards and then hesitates, waiting for a moment before burying itself in the sand again. In that brief pause, the elder dolphin shakes off the sponge, surfaces for a breath, and then comes down and snags the sand perch before it can rebury itself. She then passes it to her daughter. And with that, the younger dolphin hasn’t just gotten a good meal; more importantly, she’s learned a powerful hunting technique — one that years from now, she’ll pass along to her own offspring.
