Does Natural Visual Camouflage Reduce Turtle Nest Predation?

Egg and nest crypsis is a strategy to reduce detection by predators, thereby minimizing offspring mortality. While this strategy has been well studied in birds, it has received little attention in other taxa. Turtles are plausibly able to camouflage their subterranean nests by reducing the level of soil surface disturbance. To test the hypothesis that more cryptic nests experience lower predation, we first quantified the camouflage of natural Painted Turtle (Chrysemys picta) nests from the human perspective and demonstrated that substantial variation in nest camouflage exists. We subsequently tracked the predation fates of these nests and related nest camouflage to nest survival. Although the results trend in the expected direction, logistic regression did not yield a significant association between camouflage rating and nest survival. These results suggest turtle nests are highly detectable by predators and mothers have little ability to influence predation risk to their nests via camouflage. This work opens a previously little-explored area in nest crypsis in which further study could aid in discerning a functional connection between turtle nest camouflage and survival.