Some animal species, such as chimpanzees, dolphins, and crows, have the innate ability to use inanimate objects as tools. This behavior has only recently been documented in the swine species.
While on holiday in Paris, ecologist Meredith Root-Bernstein witnessed a Visayan warty pig—a critically endangered species native to the Philippines—using a piece of wood to dig and move soil around. At this point, Root-Bernstein had no idea as to why.
"I said, Whoa, that's pretty cool," says Root-Bernstein. "When I looked up tool use in pigs, there was nothing."
Fascinated by the potential magnitude of what she had witnessed, Root-Bernstein returned to the enclosure several times over the following weeks but was not able to observe the pigs repeating the intriguing behavior.
After conducting some research into their behavior, Root-Bernstein learned that Visayan warty pigs give birth every six months. The pigs are known to make nests lined with leaves for their arriving offspring. She then concluded that the tool using the technique must be linked to nest-building. Upon returning to the enclosure during the time the pigs would be preparing, she and a colleague were in fact able to record three of the four Visayans using tools to build their nests.
Root-Bernstein said she was surprised that no one has ever reported findings on pigs using tools but understands that due to most wild pig species being either endangered or critically endangered, observation of the species by humans is somewhat limited.
To conduct her research, which was later published in the journal Mammalian Biology, Root-Bernstein and her team recorded two adult Visayans and their two offsprings 11 times over the course of two years. During this time, the researchers found that the mother pig seemed to learn the technique on her own, later passing the knowledge to her mate and then their children.
While it is understood that animals in captivity behave differently from those in the wild, Root-Bernstein and Fernando "Dino" Gutierrez, president of the Talarak Foundation, Inc, believe that wild Visayans are likely using tools as well.
Gutierrez said he also witnessed the wild pigs utilizing their remarkable intelligence. The observation came as the pigs were faced with an electrified fence. Gutierrez said the pigs would push rocks to the fence until contact was made, then listen for clicking noises.
"Clicking means the wires are hot, and they will back off and not cross; no sounds mean it is safe to investigate what's beyond the wire," he explained.
More research is needed to understand the wild pigs' level of intelligence further. But based on Root-Bernstein's observation, it is safe to say that feral pigs are definitely one of the smartest species.
