AUDIO: “Forever After” from Soundtracks 2 by De Wolfe Music Library. Composer: Paul Lawler

Six hundred miles off the coast of Ecuador lies an archipelago called the Galápagos, famous for their connection to Charles Darwin and his theory of evolution by means of natural selection. Darwin spent five weeks there in the fall of 1835, and in 2004 I accompanied my friend and colleague Frank J. Sulloway on his expedition to retrace Darwin’s footsteps. The Ecuadorian government has ownership and jurisdiction over the archipelago and they have gone to great lengths to keep the islands as pristine and natural as possible. For example, before we were allowed to hike off trail into the interior of the islands we had to go through a careful quarantine process to ensure that no foreign invaders were hiding in our backpacks or clothes. Nevertheless, invasive species are an ongoing problem for the native populations, especially the famous Galápagos tortoises whose diet depends heavily on the local vegetation, which has been systematically eroded by goats, introduced almost a century ago and now threatening the tortoises and other species with extinction.

In response, the National Park Service of Ecuador undertook a massive goat eradication project on the most affected island—the massive 58,465-hectare Santiago Island—that resulted in the killing of over 79,000 goats in a span of four and a half years in the mid-2000s. The initial culling of the goats was done by riders on horseback, who corralled them into pens with air horns and rifle shots, and then killed them. But this method fell far short of the goal because of the brutally harsh terrain of these volcanic islands. It is dry and hot, and the razor-sharp a’a lava surface slices up your hiking boots. Bushwhacking through thorn-festered scrub brush slashes up your arms and legs. Water is hard to come by so you have to carry your supply on your back. The landscape is undulating and jagged, and there are numerous lava-formed caves, nooks, and crannies in which goats can hide from human hunters. Even though I am in good physical condition from a lifetime of competitive cycling I found this trek with Frank to be a grueling slog, among the most arduous things I have ever undertaken. Even the native Ecuadorians more acclimated to the equatorial environment had to turn to helicopters to find the remaining goats, shooting them with rifles from the air. And still the goats persisted. To finish the job the National Park Service introduced “Judas goats” and “Mata Hari goats” to find the remaining feral goats and kill them. Judas goats are goats captured from nearby islands and equipped with radio collars and then released on Santiago to lead hunters to their remaining kind in hiding. Mata Hari goats are sterilized female Judas goats chemically induced into long-term estrus so that when released they would tempt male goats who were hunter shy but female sure. At a cost of $6.1 million, it was the largest eradication of a mammalian species from an island in history.

Was this a moral act? Who should live and who should die—the native species that evolved in the Galápagos islands over the course of millions of years, or the goats that were introduced there a mere century ago?