When Spanish explorers brought pigs to what is now the southeastern United States in the 1500s, the animals were intended as a practical source of food rather than a threat to native ecosystems. Centuries of escapes, free-ranging livestock and later introductions of Eurasian wild boar changed that.

European settlers brought pigs to North America in the 1500s as a food source, leading to more than 6 million feral swine currently causing ecological and economic problems across…

When Spanish explorers brought pigs to what is now the southeastern United States in the 1500s, the animals were intended as a practical source of food rather than a threat to…