Pigs don’t receive nearly enough of the love they deserve. Although often depicted as mere mud-swilling incubators of bacon, these animals are capable of some remarkably sensitive and socially intelligent behavior.
As further proof of this, scientists have documented a group of pigs using tools for the first time.
Researchers observed Visayan warty pigs (Sus cebifrons), a critically endangered species native to just two islands in the Philippines, using sticks to dig and build nests at a zoo in France, describing it in a study in the journal Mammalian Biology.
While observing the pigs at Ménagerie du Jardin des Plantes in Paris, Meredith Root-Bernstein noticed one of the females, named Priscilla, digging a nesting area with a stick in her mouth.
"She would deposit some leaves, move them to a different spot on the mound, and dig a bit with her nose," Meredith Root-Bernstein, lead study author, wrote in her observation notes back in October 2016.
"At one point she picked up a flat piece of bark about 10 cm x 40 cm that was lying on that mound, and holding it in her mouth, used it to dig, lifting and pushing the soil backward, quite energetically and rapidly."
In a series of later experiments in 2016 and 2017, Root-Bernstein and her team of researchers later documented three out of four of the pigs scooping out soil using a stick in their mouth. This suggests, say the researchers, that the behavior was transmitted socially between the family.
Many animals can use tools, from orangutans and gibbons to octopuses and insects. Indeed, some species of animals, such as great apes, can use tools for dozens of different uses. Perhaps due to its association with human behavior, tool use is often associated with intelligence. When renowned primatologist Jane Goodall discovered that wild chimpanzees use tools, her research partner Louis Leakey reportedly said: "Now we must redefine ‘tool,’ redefine ‘man,’ or accept chimpanzees as humans.”
However, using tools doesn’t necessarily mean an animal is super-intelligent. For example, ants use tools to forage for food and are possibly self-aware, however, we don’t think of them as “smart” animals in the same sense of chimps or dolphins.
It appears that the real display of intelligence in regards to tool use is flexibility and adaptivity. It could be a different skill to use a tool because it’s instinctively hardwired into your brain, compared to innovating the use of objects based on the unique circumstance around you.
While the researchers say it’s not totally clear where the pigs’ digging behavior fits into this, they do argue it can be defined as the first observed unprompted tool use in the Suidae family, the band of mammals that includes pigs, hogs, and boars.