What do humans, ravens, octopuses, ants, and alligators have in common? Despite their immense differences, all of these creatures are capable of using tools, which scientists consider to be a major indicator of intelligence in the animal kingdom.
This honor roll of animal tool-users now has an official new member—pigs—according to a recent study published in Mammalian Biology. Led by conservation ecologist Meredith Root-Bernstein, who is a visiting researcher at the Musée de l'Homme in Paris, the authors report “the first structured observations of unprompted instrumental object manipulation in a pig, the Visayan warty pig Sus cebifrons,” according to the study.
Root-Bernstein first noticed the tool use in 2015, while visiting the zoo at the Jardin des Plantes in Paris. She observed a Visayan warty pig named Priscilla holding a piece of bark in her mouth and using it to scoop into the soil. When she later looked into the research about tool use in pigs, she found that this behavior hadn’t been reported before.
“I just happened to be in the zoo at the right moment and observed the behavior,” Root-Bernstein said in a Skype call. “Of course, it was because I knew about animal behavior that I recognized what I was seeing, but otherwise it was totally serendipity.”
Scientists already knew that pigs are pretty smart. But tool use is a new one for our porcine friends.
“I do think it’s surprising that we haven’t seen, in scientific literature, domestic pigs using tools,” said Root-Bernstein. “All pigs are considered to be intelligent—they are social and they like to manipulate objects with their mouths—so those are all good conditions under which you might expect to see tool use being invented and passed around between individual pigs.”
Root-Bernstein began to check in on the captive pigs in the months following the first lucky sighting, and figured out that the tool use was linked to nest-building behavior. Over the course of 2016 and 2017, she and her colleagues filmed the pigs using tools to prepare nests for piglets multiple times.
Priscilla was particularly adept at using the sticks to prepare for her offspring, according to CNN, and she may have taught her mate and piglets how to copy her unique skills.
“It’s interesting because we really know almost nothing about this pig’s behavior in nature,” Root-Bernstein explained. “The population left in nature is really small because their habitat [in the Philippines] has been destroyed. It is actually endangered for that reason.”
That said, there is at least one other account of Visayan warty pigs also using tools, according to Fernando “Dino” Gutierrez, who runs a foundation in the Philippines that helps protect the species. Gutierrez told National Geographic that he has seen the wild pigs picking up stones with their mouths and throwing them at electrified fences to test its defenses.
Yes, it’s like that scene in Jurassic Park—only with warty pigs instead of raptors. Life finds a way.
These new observations suggest that pigs of all kinds may have applied their ample brains to various forms of tool use. It’s also a reminder that inhumane treatment of pigs, which is unfortunately common due to their ubiquity as livestock, should be mitigated, as these animals are very cognitively advanced.
“I think it would be great if pig researchers and other animal cognition researchers would go out and look for more examples of pigs using tools or doing problem solving and other clever things,” Root-Bernstein said.
“I hope this [paper] will inspire people to look for that, if they haven’t been looking already, and to put pigs in a position where they might have the opportunity to develop tool use.”