Invasive snake causes massive reduction of all endemic herpetofauna on Gran Canaria.

Invasive snakes represent a serious threat to island biodiversity, being responsible for far-reaching impacts that are noticeably understudied, particularly regarding native reptiles. We analysed the impact of the invasive California kingsnake, -recently introduced in the Canary Islands-on the abundance of all endemic herpetofauna of the island of Gran Canaria. We quantified the density in invaded and uninvaded sites for the Gran Canaria giant lizard, , the Gran Canaria skink, , and Boettger's wall gecko, . We used spatially explicit capture-recapture and distance-sampling methods for and active searches under rocks for the abundance of the other two reptiles. The abundance of all species was lower in invaded sites, with a reduction in the number of individuals greater than 90% for , greater than 80% for and greater than 50% for in invaded sites. Our results illustrate the severe impact of on the endemic herpetofauna of Gran Canaria and highlight the need for strengthened measures to manage this invasion. We also provide further evidence of the negative consequences of invasive snakes on island reptiles and emphasize the need for further research on this matter on islands worldwide.