Eradication of Feral Pigs, Donkeys, Goats, and Rats from the Galapagos
Invasive mammals such as pigs, donkeys, goats, and rats have been an ecological disaster for fragile environments like the Galapagos since they were introduced by humans during the past few hundred years. They’ve destroyed endemic species both directly and indirectly, by ravaging vegetation and eating tortoise and sea turtle eggs/hatchlings, among other things. Many of these introduced animals have now been eradicated, despite opposition from some locals.
The methods of eradicating these invasive species range from ground hunting to aerial hunting to even poisoning. Pigs were eradicated on Santiago Island through a combined effort of ground hunting and poisoning during a campaign that stretched 30 years. Donkeys and goats have also been eliminated on Santiago, as well as other islands, using techniques such as aerial hunting and “Judas goats”. Ground hunters were often assisted by dogs, and poisoning was usually accomplished by injecting bait with substances like 1080 (sodium fluoroacetate). Aerial hunting proved to be very effective for donkeys and goats; however, goats eventually began to associate the sound of a helicopter with death. The remaining goats would hide from hunters; they were very difficult to find. To combat this issue, hunters took advantage of goats’ herding instinct by catching and releasing “Judas goats” which they tagged with tracking collars. Once released, these goats would seek out others, and lead the hunters right to them. The Judas goats would be recaptured for re-use while their newly-found herd was slaughtered. Rats, unfortunately, are harder to eliminate- that process is ongoing.
Some of these methods of eradication, such as poison and Judas goats, are obviously controversial. Personally, however, I believe the end justifies the means. The results of invasive species eradication have been immediate and significant- areas that were completely destroyed are seeing new life. With the help of seed banks, extinct species are being re-introduced, and habitats are well-suited for endemic species once again. Hopefully, as time goes on, Ecuadorian citizens living in the Galapagos will be educated on the importance of eradicating invasive species, and the last remaining populations will also be removed.