Humans are not alone in the use of tools. Chimpanzees, for instance, crack nuts with stones and use sticks to get at tasty termites. Dolphins are known to employ sponges to protect their beaks while foraging. And a Galapagos Islands finch uses cactus spines to dig grubs out of holes.
Sea otters also are members of the animal kingdom's tool-wielding club. And a new study offers a fuller understanding of the tool use - utilizing rocks and other objects to break open hard prey - by these marine mammals. It lets the otters eat certain larger prey and reduces their tooth damage by cutting down on their chomping down on hard shells, with females using tools more than males, perhaps to compensate for their smaller body size and weaker bite force, researchers found.
The researchers observed 196 southern sea otters along the central California coastline - Big Sur, Monterey, San Luis Obispo, Piedras Blancas and Elkhorn Slough.
