Unwanted Guests

People began to introduce new plants and animals to the islands as they arrived. Goats, pigs, dogs, and plants were brought to the islands to make life easier for settlers. We call them introduced species. Other living things not from the islands— rats, insects, and weeds—probably arrived on ships.

Cats are not from the Galápagos. A cat can harm native and endemic wildlife.

Wild boars, or wild pigs, now roam the islands.

Most Galápagos plants and animals weren’t exposed to things from other places. So, outside organisms put them at risk for disease or even attack. We call these invasive species. They cause damage to the islands.

Blackberry plants grow and spread quickly. They take up space native plants need to grow.

Plant Invaders

About 700 of these invasive species are plants. One plant, the wild blackberry, has been a cause for concern. It was introduced in the 1970s. It quickly spread across the islands. The blackberries crowded out the Scalesia forests on Santa Cruz and three other islands.

Scalesia plants are giant members of the daisy family. They can grow up to 15 meters (49 feet) tall. These forests are homes to a variety of bird species, including the woodpecker finch. The berries have taken over a lot of land.

Farmers consider the blackberry a weed. It turns farms into wastelands by choking out other plants. Fighting blackberries is hard work. Destroying it by hand can be back‑breaking. And killing it with herbicides is too risky. The poisons could harm other plants.

Life Science

Ecosystems and Introduced Spieces