The pigs that use tools

Researchers have spotted pigs using tools—a first for this animal, which is known for its intelligence. Many wild animals, such as chimpanzees and dolphins, make use of tools. But until now, neither wild nor domestic swine have ever been seen doing the same. That changed when Meredith Root-Bernstein, an ecologist, observed a wild pig in a Parisian zoo picking up a piece of bark in its mouth and digging in the dirt with it. Root-Bernstein hypothesized that the Visayan warty pig—a critically endangered species from the Philippines—was nest-building, something the animals do every six months to prepare for the arrival of piglets. Colleagues who returned to the zoo the next spring confirmed her theory. Three of the four pigs in the pen were using tools to create a homey nest: a pit filled with leaves. Subsequent visits yielded the same finding. Root-Bernstein says it isn’t yet clear why the pigs use tools, given that their snouts appear better suited for the task. “Learned things and cultural things work that way,” she tells NationalGeographic.com. “Maybe it just feels like the right thing to do.”

Juliette Treillet, Newscom, Joel Sartore/National Geographic Photo Ark ■