Meeting Abstract
As temperatures increase, marine turtles are at risk of a feminization skew within populations due to temperature dependent sex determination. While hatchling sex ratios can be estimated because they are accessible, adult sex ratios remain unknown because breeding females and males are not equally accessible. A functional metric is the breeding sex ratio (BSR), which is estimated from maternal sampling and paternity of clutch samples. Previous estimates of BSR for leatherback turtles (Dermochelys coriacea) nesting along Florida’s southeastern coast, were not significantly different than 1:1. This estimate did not account for females laying multiple nests per season or that they might may mate between nesting events. We reassess the 1:1 adult sex ratio estimate by analyzing samples from turtles that returned to nest multiple times (2016-2019). We sampled 27 different returning females and a subset of their subsequent nests (n=62 , 760 hatchlings). Females typically did not mate between clutches. Of the females that mated with multiple males, loss of sperm contributions across time was detected. We confirm that females mate at the beginning of the breeding season, and likely do not mate between nests. In Florida, the 1:1 BSR was supported. This leatherback population appears to be decreasing, hence characterizing the mating system is important to population structure now, before extreme environmental effects are evident.
