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.
The absence of natural predators allowed the goat population to expand unchecked, leading to a decline in the native organisms they preyed upon. The goats had a significant effect on the Galapagos tortoise population.