Communal Nesting and Parental Care in Oudri's Fan-Footed Gecko (Ptyodactylus oudrii): Field and Experimental Evidence of an Adaptive Behavior

Abstract

Oudri's Fan-Footed Gecko (Ptyodactylus oudrii) is a common North African desert lizard that lives in dense colonies. Reproductive behavior shows a number of peculiarities in egg laying. Females select communal oviposition sites in rocky recesses at human-made structures. Individuals of both sexes perform communal parental care of the eggs. We performed field observations to analyze the extent of communal nesting in nature in southeast Morocco. We also carried out laboratory experiments to analyze the function of this behavior. In Experiment 1, we assessed whether the presence of previous clutches influenced whether females select a site for oviposition. In experiment 2, we tested whether parental egg-attendance influenced the hatching success of eggs. Finally, in Experiment 3, we compared hatching success of communal and solitary clutches under laboratory conditions. Communal nesting was the generally observed in the field. With a single exception, all clutches were restricted to one area. In 32% of colonies, individuals of both sexes and all ages remained in close vicinity to clutches. Females preferred oviposition sites where freshly laid eggs were present. Hatching rate significantly decreased when adult lizards were experimentally excluded from the oviposition site, and hatching success of solitary clutches was significantly lower than that of communal ones under laboratory conditions. Our results suggest that communal nesting in this species is highly adaptive, because aggregation favors parental care, defense against predators of eggs or hatchlings, and increases incubation success. These benefits are likely to be important in geckos that live in extremely dry environments.