Because the Galápagos Islands were never connected to the mainland, the ancestors of every native animal species had to find a way here from somewhere else. Flotation rafts of natural vegetation, winds, and ocean currents all provided passage. Boobies, cormorants, giant tortoises, land iguanas, and pelicans arrived from South America. Fur sea lions and penguins rode the Humboldt Current north from the Antarctic thousands of years ago. Darwin's finches and pink flamingos came in from the Caribbean. Some land mammals even waited to hitch a ride on human vessels.
Today, as with the plants of the Galápagos, many wildlife species are struggling with the challenges that come with living in the islands. But conservation efforts have made astounding turnabouts in what were once thought to be insurmountable obstacles to the continuance of some species. Many thought to be at the brink of extinction now have significant population numbers. And tourism continues to play a big part in preserving the wildlife of the Galápagos.