Diet and reproductive aspects of the exotic gecko gehyra mutilata (Wiegmann, 1834) (Sauria: Gekkonidae) in the urban area of Chapala, Jalisco, Mexico

Abstract

We studied the diet and described some reproductiveaspects (body size, clutch size, size and egg volume, and nesting site) of the exotic gecko Gehyra mutilata in the urban area from Chapala, Jalisco, Mexico, during a period of nine months (April-December, 2013). A total of 113 adult individuals were captured, where 101 revealed to have stomach contents. We found a total of 1,563 food items, which were identified and grouped into 13 prey categories: Araneae, Blattodea, Coleoptera, Dermaptera, Diptera, Gastropoda, Hemiptera, Hymenoptera: Formicidae and Non-Formicidae, Isopoda, Lepidoptera, Orthoptera, Squamata (Gekkonidae) and Trichoptera. Diptera (Nematocera) was the most important food category in abundance (91.6%), relative frequency (34.2%), volume (68.8%), and relative importance (94.8%). Other uncountable food items as plant material and eggshell remains were present in the diet. The number of prey per stomach were between 1 to 140, with a mean of 15.5 ± 25.56, the prey volume mean was 0.29 ± 0.76 ml, with a range of <0.01 – 2.90 ml. Males had fewerprey items in their stomachs than females, but no significant differences were found between sexes. Diet diversity (1D) between males and females was evaluated, which was similar with almost two effective food categories for both sexes. The trophic niche overlap between sexes showed a high numeric and volumetric similarity in their diet. Snout-vent length did not significantly differ between males and adult females. The mean clutch size was 2 eggs, even though the nesting site can be composed of larger egg clusters. The nesting sites consisted on holes, crevices and inside electric installations on building walls. The mean egg length was 10.47 ± 0.541, with a mean width of 8.40 ± 0.256, while the mean volume was 387.92 ± 43.297 mm3. The present study suggests that the opportunist habits of G. mutilata are a determinant factor on its diet composition within the urban area of Chapala.