Factors Affecting Nest Site Selection by Freshwater Turtles: A Systematic Review

Nest site selection is an important behavior, particularly in species that lack parental care, as nest microclimate can greatly impact embryos’ survival and offspring phenotype. Understanding which factors influence oviposition decisions is critical to identifying priority areas for conservation. This systematic review aimed to synthesize the factors that affect nest site selection by freshwater turtles. The search was conducted in the Web of Science database. In total, 35 publications met the eligibility criteria. The first study on the topic was published more than three decades ago, but only within the last ten years have studies started to be published annually. More than half of the studies were conducted in the United States and the most studied species was Chrysemys picta. Environmental factors, mainly vegetation characteristics, but also soil properties and beach morphology, are the most studied. Anthropogenic factors have been increasingly studied, especially residential areas and agricultural fields. Some studies suggest that human-altered habitats may act as ecological traps, emphasizing the need for further research on this topic. More studies are also needed on the influence of predation risk, co-species cues, female size, and offspring phenotype on nest site selection by freshwater turtles. We highlight that understanding the factors affecting nest site selection is important for identifying the habitat needs of nesting females, predicting possible ecological implications of nest site choice, assessing the adaptive potential of species to environmental change, and determining the vulnerability of populations to different threats.