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Department of Zoology

Cat and iguna.  Photo credit: C. Marmion

Two species introduced to the Galápagos, the cat (brought to the islands decades ago) and the smooth-billed ani (a more recent arrival) have been studied by PhD student Sophia Cooke.  The results of both these studies have just been published:

Cooke, S.C., Anchundia, D., Caton, E. et al. Endemic species predation by the introduced smooth-billed ani in Galápagos. Biol Invasions (2020). 

The smooth-billed ani Crotophaga ani was introduced to Galápagos in the 1960’s and has since spread to almost all the islands and reached an estimated population of over 250,000. Last year we published a full review into their history and suspected impacts on the islands, which highlighted their predation of many endemic species, including Darwin’s finches. Following this, we recently published the results of a dietary analysis, reporting for the first time that they are predating on endemic snakes and scorpions as well as large numbers of the endemic Galápagos carpenter bee, a major pollinator on the islands.

MacLeod, A., Cooke, S.C. & Trillmich, F. The spatial ecology of invasive feral cats Felis catus on San Cristóbal, Galápagos: first insights from GPS collars. Mamm Res (2020).

Feral cats are thought to be a serious problem in Galápagos, predating on many native and endemic species, including Galápagos marine iguanas. We undertook a pilot study of their movements on one island. Through analysis of GPS collar data from a small number of cats, we found evidence to support locally reported predation of turtle hatchlings by cats as well as their frequent use of iguana nesting habitat. 

Further research is needed to understand the predation impacts of both of these introduced species and the impacts they have on the broader diversity of the archipelago .

Photo credit: J. Lynton-Jenkins (ani & finch) and C. Marmion (cat & iguana)