The damage caused by introduced land mammals is clear to see and therefore prominent in the minds of those concerned about the survival of native and endemic species in the Galapagos Islands.
Introduced mammals present in Galapagos include the house mouse (Mus musculus), black or ship rats (Rattus rattus), brown rats (Rattus norvegicus), guinea pigs (Cavia porcellus), rabbits (Oryctolagus cuniculus), dogs (Canis familiaris), cats (Felis catus), donkeys (Equus asinus), goats (Capra hircus), horses (Equus caballus), cattle (Bos tauro), and pigs (Sus scrofa).
Rats, cats, and goats have been the cause of many conservation problems around the world. Feral goats have caused immeasurable damage to Galapagos ecosystems, ravaging habitats and putting endemic species, including plants and the iconic giant tortoises, at risk. Black rats are amongst the worst of the introduced species, spreading rapidly between islands, competing with endemic rice rat populations. They destroy bird and reptile nests and eggs and consume hatchlings, as well as carrying diseases which affect human and animal health. Cats are highly predatory, targeting birds, lava lizards, endemic snakes, and young iguanas. The perception of cats as pets rather than as ruthless killers makes it difficult to gain acceptance for the control of cats in Galapagos.
An intensive campaign continues to focus on the control and eradication of invasive mammals in Galapagos. Successes include eradication of cats from Baltra Island, and Project Isabela, a program to eradicate goats from Santiago and northern Isabela Islands, amongst other successes. Rats and cats are the next targets for control programs that are the joint effort of the CDF and the Galapagos National Park Service.
CDF Fact sheets on introduced land mammals in Galapagos