Thewild catsThey are one of theinvasive species most damaging to vertebrate communities living on islands, according to a study directed by the Higher Council for Scientific Research (CSIC). Analyzes reveal that, throughout history,the action of these felines has contributed to the disappearance of at least 14% of extinct vertebrates. Currently, its presence threatens, in addition, the survival of 8% of the species ofbirds, mammals and reptileslisted as critically endangered by the International Union for Conservation of Nature (IUCN).
The work, published in the latest issue of the magazineGlobal Change Biology, is based on a bibliographic review of 229 cases in 120 islands of the world. Analysis reveals that feral cats are present in most of the approximately 179,000 islands in the world. ? These environments are home to a very particular and valuable biodiversity, since many of their species are endemic and the island territory is usually limited, so this type of impact is much more serious ?, explains Manuel Nogales, the Institute researcher of Natural Products and Agrobiology of the CSIC.
At a global level, the island regions historically most affected by the action of this feline arethe Galapagos (Ecuador), Hawaii (USA), some Caribbean islands and the Canaries. The data show that the biodiversity of the two Spanish archipelagos has also been affected by the action of these cats. The endemic giant lizards of La Gomera and El Hierro, classified as critically endangered by the IUCN, “now only inhabit certain cliffs where cats have difficult access,” explains the CSIC researcher.
During the investigation, the team identified some striking cases where the cat has played a key role in the extinction of some vertebrates, such as Stephens’ wren (Traversia lyalli) in the Cook Strait (New Zealand) and the Socorro turtle dove (Zenayda graisoni) in Mexico, whose species is extinct in nature and its only existing troops are in captivity. In addition, some subspecies of the endemic mouse (Peromyscus guard) from Baja California (Mexico) have become extinct on several islands. The giant lizard of La Gomera (Gallotia gomerana), with a meager population in nature, is one of the most threatened reptiles on the planet, says Nogales.
To avoid the damage of its presence on the island biodiversity, Nogales recommends “thetotal eradication of feral cats on islands with an area of less than 200 square kilometersand the control of their populations in those of greater size where the damage caused to biodiversity is remarkable “.
