original_query: What is the impact of feral cats on islands' biodiversity?
query: What is the impact of feral cats on islands' biodiversity?
answer: Feral cats introduced to islands have had a devastating impact on biodiversity, causing extinctions of several species and local extinctions.  They are implicated in the extinction of 40% of species studied in one statistical analysis; no other alien predator has had such a universally damaging effect.  The impact is particularly severe on islands with ecologically naive species that lack predator responses.