Feral goats were brought there by humans for agricultural purposes and have had a huge impact on the ecosystem. They are dangerous to the environment because they are voracious eaters and destroyers of habitat. They have no natural predators, which is why their population continues to grow.
Goats have had a huge impact on the tortoise population in the Galapagos, eating all the food and resources the tortoises needed, eventually leading to their extinction.
