This grassland was once covered by thick forest.
Between Man and Goat
Invasive species include animals, too. There are 13 introduced species of mammals in the Galápagos.✻ The one that has caused the most damage is the goat. Whalers, pirates, and fishers introduced goats to the islands in the 1850s. With no island predators and the ability to breed twice a year, the goat population grew quickly. By the late 1990s, the number of goats reached six figures.
Goats are known for their appetites. Over time, they ate their way through large patches of land. What’s worse, they ate the same things the tortoises ate, including the prickly pear cactus.
✻Bats and rice rats are the only mammals native to the Galápagos Islands.
Taking Back the Islands
Once an invasive species takes over, how do you get rid of it? Galápagos farmers fight the blackberry one plant at a time. They rip them out by hand.
Tackling the goat problem was another matter. The goats were causing erosion and threatening the survival of rare plants and trees. The goats had to go. Project Isabela was enacted in 2004. Tens of thousands of goats were killed to protect the islands. Plant and animal life began to rebound. The plan was used on other islands, too. The Galápagos is now largely goat‑free.
a herd of goats on Isabela Island
Invasive species pose a real threat to the islands. Each must be monitored and managed to protect the islands.
Goats eat plants like prickly pear cactus, which is food for giant tortoises, land iguanas, doves, cactus finches, and mockingbirds.