On an October day in 2015, ecologist Meredith Root-Bernstein was watching a family of rare pigs at a Parisian zoo when something caught her eye.
One of the Visayan warty pigs—a critically endangered species native to the Philippines—picked up a piece of bark in its mouth and started digging with it, pushing the soil around. “I said, Whoa, that’s pretty cool,” says Root-Bernstein, a visiting researcher at the Musée de l’Homme in Paris and a National Geographic Explorer. “When I looked up tool use in pigs, there was nothing.”
Intrigued, the scientist returned to the menagerie at the Jardin des Plantes frequently over the following months to try to observe the behavior again, to no avail. She hypothesized that what she’d seen was related to nest-building, which Visayans generally do every six months to prepare for the arrival of piglets. Sure enough, the next spring, a colleague returned to the warty pig enclosure and recorded three of the four animals using tools to complete their nest, an earthen pit filled with leaves. (Learn more about the Visayan and its rockstar mohawk.)
Though many wild species use tools, from chimpanzees to crows to dolphins, no one has reported the phenomenon in any pig, including the 17 wild pig species and domestic swine. This surprised Root-Bernstein, especially considering the Suidae family’s well-known intelligence.
But because wild pigs are so little studied and, in most cases, either endangered or critically endangered, it may not be so unusual that such innovation has escaped human eyes, says Root-Bernstein, whose study appeared in September in the journal Mammalian Biology. (Read why we love—and loathe—the humble pig.)
She says tool use is particularly fascinating to study because it’s a trait shared with humans, as well as one that may highlight a common evolutionary history. “It brings us closer to animals,” she says, “and helps us realize it’s all connected.”….[ ]