These goats did not have natural predators, thus their population continued to grow, which led to a decrease in native organisms they prey on. The goats had a huge impact on a specific species on the island, the Galapagos tortoise.
Because there were no natural predators for these goats, their numbers increased, which resulted in a decrease in the number of native animals that they consumed. This led to a major impact on a particular species on the island, the Galapagos tortoise.