ABSTRACT
In Galápagos, invasive species present the largest threat to terrestrial biodiversity (Snell et al. 2002). Introduced species were first noted in Galápagos in the seventeenth century, increasing steadily since the 1830s and rising most rapidly in the last 50 years (Causton and Sevilla 2008; Deem et al. 2008; Jimenez- Uzcátegui et al. 2008; Tye 2007b). In 2008, the tally of introduced terrestrial species was 1,445 including 870 plants, 536 invertebrates, 30 vertebrates and ten diseases (Table 12.1). Of these introduced species, many have invaded native ecosystems. Vertebrate invasions were the first to cause impact and alarm in the latter half of the twentieth century. These have been followed by plant and invertebrate invasions that now cover huge areas, particularly in the highland regions of the inhabited islands (Causton et al. 2006; Watson et al. 2009) and further invasions are expected in the future (Trueman et al., in press)
