Finally this is proven. It is by no means surprising. Wild domestic pigs, which I know are a different species, are a plague in much of North America and Australia partially due to their intelligence. Half the North American pig problem is in Texas where an estimated 2-2.5 million pigs roam the country side. Because they are such a threat to the environment and their population is so out of control there is no limit on hunting them in either season or quantity.

Pigs are particularly challenging to control because of their intelligence and lack of predators. Because of their size, intelligence, and aggressiveness they have no natural predators in Texas. They are quick to learn of hunting traps and will either avoid or disarm them. A herd of pigs reduced in population by 70% can rebound within 2-3 years without continued management.

They tear up the land and are a serious threat to the natural ecology and food supply. Their damage to commercial agriculture is estimated at $50 million per year, but their damage to property and the environment is estimated at close to half a billion each year. Because of their high intelligence they are adapting their range from rural areas to suburbs and urban areas. Unlike coyotes, which have also adapted from rural to urban areas with great success, they are often not afraid of people are known to hurt people in attacks.

https://en.wikipedia.org/wiki/Feral_pig