Page "Pig" Paragraph 45

Domestic pigs that have escaped from farms or were allowed to forage in the wild, and in some cases wild boars which were introduced as prey for hunting, have given rise to large populations of feral pigs in North and South America, Australia, New Zealand, Hawaii, and other areas where pigs are not native.

Accidental or deliberate releases of pigs into countries or environments where they are an alien species have caused extensive environmental change.

Their omnivorous diet, aggressive behaviour, and their feeding method of rooting in the ground all combine to severely alter ecosystems unused to pigs.

Pigs will even eat small animals and destroy nests of ground nesting birds.

The Invasive Species Specialist Group lists feral pigs on the list of the world's 100 worst invasive species and says: