Competition between a non-native (Gekkonidae: Hemidactylus mabouia) and a native (Phyllodactylidae: Gymnodactylus darwinii) lizard at a reforested area in southeastern Brazil

Invasion of non-native species affect the ecosystem functioning and is considered one of the main causes of biodiversity loss. If the niche at the novel site was already occupied by a native species, the non-native will possibly outcompete the native. We studied aspects of morphology, diet, habitat and reproduction of the non-native Hemidactylus mabouia and the native Gymnodactylus darwinii at a reforested area in southeastern Brazil. Hemidactylus mabouia is larger and heavier than G. darwinii. Hemidactylus mabouia feed on the same five prey orders found in stomach contents of G. darwinii but ate a larger array of prey types. For both species, Isopods predominated in prey frequency and number, whereas Lepidoptera larvae predominated in wet mass. Prey overlap was 46% regarding prey number and 57% regarding prey weight. Both species have trophic ontogeny based on SVL. Both species use leaf litter and tree barks as refuge and oviposition microhabitat. Both species reproduce mainly from September to March (rainy season) but H. mabouia has a more protracted reproductive period. Our results indicated that the studied populations have compete in this reforested area feeding on similar prey types, sharing the same refuge and oviposition microhabitat, and having similar reproductive period. Apparently, H. mabouia is a better competitor than G. darwinii. Long-term monitoring of both species in our study area is required to investigate whether the native G. darwinii will coexist or be outcompeted by the non-native H. mabouia.