title: Strong male-biased operational sex ratio in a breeding population of loggerhead turtles (Caretta caretta) inferred by paternal genotype reconstruction analysis.
abstract: Characterization of a species mating systems is fundamental for understanding the natural history and evolution of that species. Polyandry can result in the multiple paternity of progeny arrays. The only previous study of the loggerhead turtle (Caretta caretta) in the USA showed that within the large peninsular Florida subpopulation, multiple paternity occurs in approximately 30% of clutches. Our study tested clutches from the smaller northern subpopulation for the presence of multiple paternal contributions. We examined mothers and up to 20 offspring from 19.5% of clutches laid across three nesting seasons (2008-2010) on the small nesting beach on Wassaw Island, Georgia, USA. We found that 75% of clutches sampled had multiple fathers with an average of 2.65 fathers per nest (1-7 fathers found). The average number of fathers per clutch varied among years and increased with female size. There was no relationship between number of fathers and hatching success. Finally, we found 195 individual paternal genotypes and determined that each male contributed to no more than a single clutch over the 3-year sampling period. Together these results suggest that the operational sex ratio is male-biased at this site.
authors.affiliation: Department of Biology, Georgia Southern University, BIOSC 9999 4324 Old Register Road, Statesboro, Georgia, 30460 ; Department of Biology, Florida Atlantic University 777 Glades Road, Boca Raton, Florida, 33431.
authors.forename: Jacob A
authors.initials: JA
authors.lastname: Lasala
authors.affiliation: Department of Biology, Georgia Southern University, BIOSC 9999 4324 Old Register Road, Statesboro, Georgia, 30460.
authors.forename: J Scott
authors.initials: JS
authors.lastname: Harrison
authors.affiliation: Caretta Research Project P.O. Box 9841, Savannah, Georgia, 31412.
authors.forename: Kris L
authors.initials: KL
authors.lastname: Williams
authors.affiliation: Department of Biology, Georgia Southern University, BIOSC 9999 4324 Old Register Road, Statesboro, Georgia, 30460.
authors.forename: David C
authors.initials: DC
authors.lastname: Rostal
keywords: Caretta caretta; Northwest Atlantic Ocean; conservation genetics; microsatellites; paternal contributions; polyandry