About 5% of the population of bottlenose dolphins in Shark Bay, Australia, use a foraging method first spotted by scientists in 1984 in a female dolphin they dubbed “sponging Eve.” She had a marine sponge on her rostrum, and she used it to protect her schnoz from the digging she was doing in the seafloor, hunting for a lipid-rich fish. Because these types of fish lack swim bladders, they’re undetectable by echolocation. (Which to my mind kicks up all sorts of questions- how did the dolphins know about them in the first place? What kind of learning, problem solving, and strategy are they capable of if they discovered fish that are nutritious for them buried in the seabed without using their primary sense mode, and then figured out how to get them with reduced harm to their own bodies?)
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