Invasive Species on Galápagos Donkeys Melanie Moreno

Galápagos The Galápagos Islands are an archipelago of volcanic islands distributed on either side of the Equator in the Pacific Ocean. There are many species that are only from Galápagos like its marine iguana, finches, penguins, fur seals, tortoises and many more.

What are invasive species? An invasive species is an organism (plant, animal, fungus, or bacterium) that is not native of that specific ecosystem and has negative effects on its environment.

Some invasive species in the Galápagos are goats, tilapia, feral cats, pigs, rats and other species of animals, as well as plants. Name of Species How Introduced Impact Control Goats (Capra hircus) Goats were introduced by settlers of the twentieth century as a way to ensure fresh meat. The large flocks of goats can move across the steep volcanic slopes, removing the protective cover of vegetation, this also leads to the rare soil that took thousands of years to form, to be lost by rains. Goats are also eating many plants that are from the Galapagos and will eventually wipe out its biodiversity, leaving the original ecosystems a small chance of recovery. Some eradication strategies that are being used are aerial hunting, which is very effective for rapidly reducing the total number of goats by helicopter and another one is hunting by land, which are large hunting groups that have the aid of specially trained dogs.

Black Rat (Rattus rattus) They were probably introduced to the islands by pirate buccaneer ships in the late seventeenth century. Rodents have caused problems, primarily in planted fields, as well as transmitting diseases to humans. In 2007 worldwide organisations like the Charles Darwin Foundation, helped support an international workshop on Santa Cruz Island, which has the participation of experts in rodent management from the entire world, to help with the invasion of these species. Donkeys Donkeys were introduced in the twentieth century. For the colonist donkeys were essential due to the fact that they were used for transportation. Donkeys have had part of the large impact the invasive species have caused, by the damage they have created in nature. The Isabela Project main focus was to eradicate goats, however it contributed largely to the eradication of donkeys. Feral Cats (Felis Catus) Cats were introduces by ships who visited the islands and by colonists as pets. They have been present on the five inhabited islands that are Baltra, Santa Cruz, San Cristóbal, Floreana and Isabela These cats are very aggressive predators that attack native wildlife, including birds, iguanas and lava lizards. Cats are being controlled by a program for control and eradication of Feral cats of the directorate of the Galapagos National Park, which focus its efforts on monitoring and controlling these specie.

Donkeys Like Goats donkeys were introduced by humans, In the twentieth century. For the colonist donkeys were essential due to the fact that they were used for transportation.

However they were reverted to a wild state, after escaping to the interior of the Islands.

Impact The damage the donkeys created wasn't assessed until the end of the century. Even though there were less donkeys than goats, they created the same amount of damage to the ecosystem.

Control The Isabela Project was primarily focused on eradicating goats however it contributing on eradicating the donkeys. Donkeys have been eradicated from the Santiago Island. Overall 340 donkeys were removed.

1,520 donkeys were eliminated on the nothern part of Isabela island 1,520 donkeys were eliminated on the nothern part of Isabela island. About 1,102 donkeys were removed on the southern of Isabela. In the early of 2007 all donkeys of Floreana Island were eradicated. It was a total of 302.

Bibliography http://www.env.gov.yk.ca/animals-habitat/invasivespecies.php http://www.galapagospark.org/nophprg.php?page=parque_nacional_introducidas_asnos&set_lang=en