Nesting in Reptiles: Natural and Anthropogenic Threats and Evolutionary Responses

The choice of where to lay eggs is the last maternal behavior affecting developing embryos in animals without parental care such as most reptiles, which typically abandon their eggs after laying. The eggs are then subject to a variety of threats such as predation, flooding, overheating, desiccation and pathogens. Moreover, there is evidence that anthropogenic effects are intensifying or compounding those threats. For example, future climate warming will cause ground temperatures to rise above those required for the successful development of the immobile eggs and the production of viable offspring sex ratios, ‘exerting pressure’ on mothers to evolve nesting behaviors that offset increasing temperatures. Similarly, human-induced population increases in egg predators (e.g., raccoons) appear to have elevated predation rates in turtles, the reptilian group in which we know the most about nesting.

The relationship between nest site choice and embryonic survival has not been extensively reviewed for reptiles despite its apparent importance and the question of whether reptiles can meet the challenges of anthropogenic threats. On the one hand, the persistence of reptiles across previous catastrophes including climate events supports the notion that reptiles can flourish using ‘evolutionary rescue’ alone. On the other hand, the acceleration and magnitude of anthropogenic influences on climate change and predator densities may be outpacing evolutionary responses in these species, particularly long-lived ones. A much more complete understanding of nesting behavior and its consequences in embryonic survival in reptiles, within a dynamic anthropogenic context, is essential for elucidating patterns between threats and responses. Such patterns will inform investigations attempting to predict evolutionary responses of mothers to current and future threats.

The purpose of this research topic is to bring together recent and current research on nest site choice and its consequences in a diversity of reptiles from a variety of ecosystems across different regions of the world. In particular, we will focus on establishing links between nest site choice and hatching success across different threats, and whether similar (or diverse) patterns emerge for certain groups of reptiles (e.g., turtles vs. lizards).

We welcome manuscripts on the following subjects:

• Nest site choice in any reptile, especially linking it with nest survival, hatching success or offspring sex
• Reviews of the nesting biology of certain reptile groups
• Real or predicted responses of reptiles to threats
• Modelling the impacts of threats on nest success in reptiles
• Heritability of nest site choice in any reptile