Such signals can help dolphins reach prey hiding on the sea floor. Bottlenose dolphins do what is called hole feeding, said Denise Herzing, a marine mammal scientist with the Wild Dolphin Project in Florida, who was not involved in the study. “They dig,” she said. “They stuck their beaks in the sand, almost up to their eyeballs, and extracted these snakes.” She said the sand may make it difficult for dolphins to detect buried fish through echolocation.
Other researchers urged caution. Juliana Lopez Marulanda, a marine biologist at the University of Paris Nanterre, said the study used two dolphins, and “we don’t know if this ability is actually used in the wild.”
Dolphins may also use electrical sensitivity to navigate. Dr. Lopez Marulanda and others have observed that dolphins can sense magnetic fields. Because they have bits of magnetic matter in their bodies, the electrical sense may allow them to sense changes in the Earth’s magnetic field and use something like a magnetic map.
Dr. Denhardt wonders whether electrical sensing might explain mass strandings of healthy whales and dolphins. Researchers have Links noted Between shifts in the magnetic field, such as during solar storms, and mass stranding. “This may explain, for the first time, on a sensory basis how this actually happens,” he said. He pointed out that such strandings do not occur in baleen whales, which – unlike their toothed cousins - use the mustaches they are born with throughout their lives.
Dr Lopez Marulanda said a better understanding of dolphins’ senses could help protect the animals. For example, once the electrical sensitivity of sharks was discovered, some fishing fleets added electromagnetic devices to nets to keep sharks away. She said it might be possible for something similar to happen with dolphins, although they are much less sensitive.
For an animal that has received so much research attention, it’s exciting to discover a new sense.
“Everything has been done to this type,” Dr. Denhardt said. “And there’s still something new we can discover.”
“Web maven. Infuriatingly humble beer geek. Bacon fanatic. Typical creator. Music expert.”