title: Spatio-temporal variation in the incubation duration and sex ratio of hawksbill hatchlings: implication for future management.
abstract: Climate change poses a unique threat to species with temperature dependent sex determination (TSD), such as marine turtles, where increases in temperature can result in extreme sex ratio biases. Knowledge of the primary sex ratio of populations with TSD is key for providing a baseline to inform management strategies and to accurately predict how future climate changes may affect turtle populations. However, there is a lack of robust data on offspring sex ratio at appropriate temporal and spatial scales to inform management decisions. To address this, we estimate the primary sex ratio of hawksbill hatchlings, Eretmochelys imbricata, from incubation duration of 5514 in situ nests from 10 nesting beaches from two regions in Brazil over the last 27 years. A strong female bias was estimated in all beaches, with 96% and 89% average female sex ratios produced in Bahia (BA) and Rio Grande do Norte (RN). Both inter-annual (BA, 88 to 99%; RN, 75 to 96% female) and inter-beach (BA, 92% to 97%; RN, 81% to 92% female) variability in mean offspring sex ratio was observed. These findings will guide management decisions in Brazil and provide further evidence of highly female-skew sex ratios in hawksbill turtles.
authors.affiliation: Fundação Pró Tamar, Rua Rubens Guelli, 134 sala 307, Salvador Bahia CEP 41815-135, Brazil.
authors.forename: Maria A G
authors.initials: MA
authors.lastname: dei Marcovaldi
authors.affiliation: Fundação Pró Tamar, Rua Rubens Guelli, 134 sala 307, Salvador Bahia CEP 41815-135, Brazil.
authors.forename: Armando J B
authors.initials: AJ
authors.lastname: Santos
authors.affiliation: Fundação Pró Tamar, Rua Rubens Guelli, 134 sala 307, Salvador Bahia CEP 41815-135, Brazil.
authors.forename: Alexsandro S
authors.initials: AS
authors.lastname: Santos
authors.affiliation: Archie Carr Center for Sea Turtle Research, Department of Biology, University of Florida, Gainesville, FL 32611, USA.
authors.forename: Luciano S
authors.initials: LS
authors.lastname: Soares
authors.affiliation: Fundação Pró Tamar, Rua Rubens Guelli, 134 sala 307, Salvador Bahia CEP 41815-135, Brazil.
authors.forename: Gustave G
authors.initials: GG
authors.lastname: Lopez
authors.affiliation: NC Wildlife Resources Commission, Beaufort, NC 28516, USA.
authors.forename: Matthew H
authors.initials: MH
authors.lastname: Godfrey
authors.affiliation: Fundação Pró Tamar, Rua Rubens Guelli, 134 sala 307, Salvador Bahia CEP 41815-135, Brazil.
authors.forename: Milagros
authors.initials: M
authors.lastname: López-Mendilaharsu
authors.affiliation: Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville 4811, Queensland, Australia; School of Earth and Environmental Sciences, James Cook University, Townsville 4811, Queensland, Australia. Electronic address: mariana.fuentes@jcu.edu.au.
authors.forename: Mariana M P B
authors.initials: MM
authors.lastname: Fuentes
mesh_terms: D000064:Acclimatization; D000818:Animals; D017753:Ecosystem; D005260:Female; D008297:Male; D009425:Nesting Behavior; D012744:Sex Ratio; D014426:Turtles / Q000196:embryology / Q000502:physiology*
keywords: Brazil; Climate change; Hawksbill turtle; Marine turtles; Pivotal incubation temperature; Sex ratio