Necrotic Egg and Hatchling Remains Are Key Factors Attracting Dipterans to Sea Turtle (Caretta Caretta, Chelonia Mydas, Natator Depressus) Nests in Central Queensland, Australia

Abstract

Although infestation of turtle nests by dipteran larvae is known to occur in both freshwater and marine species around the globe, the role of insects in turtle nests remains unclear in this relatively understudied phenomenon. The present study was part of a larger effort to elucidate the role of dipterans in sea turtle nests at rookeries in Central Queensland, Australia; this portion of the study examined the factors that predispose nests to infestation. Physical and biological nest parameters were measured in relation to the number of infested eggs and hatchlings in individual sea turtle nests. Data collected during the 2003–2005 turtle nesting seasons were analyzed by multiple forward regression, as an analytical tool to explore dipteran infestation events. The most significant factor predisposing nests to infestation was the number of dead propagules present (dead eggs and dead hatchlings, combined), reinforcing the hypothesis that dipteran larvae are scavengers of necrotic material in affected nests. Other factors play secondary roles in determining a nest's propensity for infestation, including nest depth, clutch size, and cumulative rainfall in the weeks preceding hatching. This study furthers our understanding of dipteran scavenger species and discusses the potentially positive benefits their actions may impart to the beach ecosystem.