The vulnerability of skinks to predation by introduced mongoose in the Fiji Islands

Abstract

Skinks are successful colonisers and are commonly found throughout the Pacific islands, but, the presence of introduced predators such as mongoose are known to threaten their survival. The two most abundant skinks found within the Fiji Islands are Emoia cyanura and E. impar; the abundance of these species encountered during visual transect counts on 16 islands within four habitats formed the basis of this study. Half of these islands had mongoose present whilst the other half were known to be mongoose free. Our results showed that skink abundances on mongoose free islands were approximately five times higher than when mongoose were present, irrespective of habitat type. We conclude that it was very likely that mongoose severely supressed even commonly found skink species across all the habitat types on these small islands. Conservation actions that could protect these native species include biosecurity mechanisms to prevent secondary invasion of introduced predators, habitat protection and management, and captive rearing programs. Failure to implement such actions now could result in even common species being at risk of extirpation.