Last summer, after spending a week in the Galápagos, I wrote a six-part series for The Last Word on Nothing about what I had learned. I’m on vacation this week, so I figured it was a good time to re-publish the series for Phenomena readers. The following is the fifth installment; here’s the first, second, third, and fourth.



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Judas knew what he was doing when he double-crossed his friend Jesus. “What will you give me if I betray him to you?” he asked the conspiring priests in the famous Bible story.

The story of the Judas Goat is more tragic. She had no idea that she was leading her friends to their deaths.

Her captors sterilized her first, then coated her with hormones so she reeked of fertility. Then they collared her with a radio-tracking device and cut her loose. Nearby male goats smelled her and sought her out. As soon as they found her, people swooped in and shot them. The hunters saved Judas, though, so they could repeat the set-up again and again.

It was all part of a six-year, $6 million project in which conservationists killed nearly 80,000 feral goats on Santiago Island in the Galápagos. Similar goat genocides had happened on 128 other islands, including nearby Pinta, but never on any as large as Santiago, which spans 144,470 acres. The goats, introduced by sailers hundreds of years earlier, were decimating all flavors of vegetation there, putting ground birds, giant tortoises and other endemic species in danger. So officials — conservationists from the Galápagos National Park and the Charles Darwin Foundation — decided the goats had to go.

The logistical details are fascinating. The first phase, from December 2001 to January 2004, was ground hunting. Researchers recruited locals, many of whom had never hunted before, and taught them how to use hunting dogs, rifles, radios, telemetry and GPS. Then they started the cold and systematic business of killing. I let out a little gasp when reading a description of one of the techniques from a research paper:

During the first 2 years of the campaign, we corralled goats in the highlands where they concentrated during dry months. We constructed temporary corrals with winged extensions of netting (10 x 10-cm mesh) strung between trees or posts at an average of 1.8 m high, with a skirt hanging on the ground weighted down with rocks. We used winged extensions, up to 6.5 km long, to funnel animals into corrals. Goats were mustered into corrals by hunters on foot or horseback, along with the aid of air horns and rifle shots. We euthanized corralled goats in accordance with American Association of Zoo Veterinarians guidelines.

I looked up those guidelines. For wildlife management of goats, they recommend an overdose of succinylcholine followed by a stun-gun or shotgun to the head.

The ground-hunting phase of the project killed 53,782 goats. The second phase was three months of aerial attacks, by specialized hunters from New Zealand using semi-automatic rifles. This video tells you all you need to know about Phase 2:

Ground and aerial hunting wiped out 98.5 percent of the goat population on Santiago. But the thing about eradication is, you can’t just do a pretty good job. If one pregnant goat manages to escape, all of your progress could be reversed. As the researchers explain in that paper: “For large-scale eradications to succeed and maximize the conservation return on investment, an eradication ethic is essential. Every animal, from the ﬁrst to the last, must be treated as the last animal on the island. The campaign must embrace a zero-escape policy.” That’s why the Judas Goat is so important: she finishes the job.

There were 213 Judas Goats involved in the Santiago job: males, females and hormone-doused females. The latter, nicknamed Mata Haris, were most effective. Between June 2004 and November 2005, Judas Goats entrapped 1,174 others, completing the eradication. A year later, the researchers came back and covered the entire island again with hunters and dogs. The only goats left were Judas Goats.

At the time, it was the largest and most successful mammal eradication project ever done. Previous efforts had taken two or three decades to kill far fewer animals, partly because they only used a few dozen Judas Goats. After the win on Santiago, authorities launched another eradication campaign on the much larger island of Isabela. The top half of the island, which is not inhabited by humans, is now also clear of goats. On both islands, after the goats left the vegetation came back with a vengeance, and so did some endemic species. On Santiago, the population of the Galápagos rail, a brown ground bird, went up more than 10 times.

Rationally, I should have no trouble with these mass killings. I’m not a vegetarian and not particularly fond of goats. The researchers seem to have followed ethical standards, and they’re doing it all in the name of biodiversity. And yet, emotionally, hearing about these killing sprees makes me queasy.

I’m not the only one. After I got back to the States, one of my fellow travelers wrote me this in an email:

I really enjoyed the trip, but the one big downer for me was the extermination of the goats and the donkeys and their very anti-Darwin approach… Everything has a right to live. The goats could have been herded and shipped to Australia. Not as cheap or as macho as slaughtering them from helicopters, but then no-kill shelters cost more to run than kill shelters. As you can guess I did not contribute to the continued extermination of non-endemic species in the Galapagos.

It makes me wonder if these eradication campaigns, for all the good they’ve done, also have serious downsides. Are they, in fact, anti-Darwinian (in any way that matters, scientifically)? And is this negative emotional reaction causing lots of tourists to hold on to money that they’d otherwise donate to conservation organizations?

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Photo by Randal Vegter