TY - JOUR
T1 - Determinants of reproductive success and offspring sex in a turtle with environmental sex determination
AU - Doody, J. Sean
AU - Georges, Arthur
AU - Young, J E
N1 - J. S. DOODY, A. GEORGES, J. E. YOUNG; Determinants of reproductive success and offspring sex in a turtle with environmental sex determination, Biological Journal of the Linnean Society, Volume 81, Issue 1, 1 January 2004, Pages 1–16, https://doi.org/10.1111/j.1095-8312.2004.00250.x
PY - 2004/1/1
Y1 - 2004/1/1
N2 - Despite the importance of maternal effects in evolution, and knowledge of links among nest site choice, timing of nesting, offspring sex, and reproductive success in animals with environmental sex determination, these attributes have not been rigorously studied in a combined and natural I context. To address this need we studied the relationships between three maternal traits (nest site choice, lay date, and nest depth) and two fitness-related attributes of offspring (hatchling sex and embryonic survival) in the riverine turtle Carettochelys insculpta, a species with temperature-dependent sex determination, for four years. Predation and flooding were the major sources of embryonic mortality in 191 nests. Embryonic survival was influenced by both lay date and nest site choice: in one year when nesting began later than average, nests laid later and at lower elevations were destroyed by early wet season river rises. In other years early nesting precluded flood mortality. However, turtles did not nest at the highest available elevations, and a field experiment confirmed that turtles were constrained to nest at lower elevations where they could construct a nest chamber. The principal determinant of hatchling sex in 140 nests was lay date, which in turn was apparently related to the magnitude of the previous wet season(s). Clutches laid earlier in the season (a female's first clutch) produced mainly males, while later clutches (her second clutch) yielded mostly females, due to seasonal increases in air temperatures. Accordingly, later nesting produced female-biased hatchling sex ratios in 1996, while earlier nesting resulted in sex ratios near unity in the other years. However, all-female nests were more likely to be flooded than mixed-sex or all-male nests in years when nesting was late. In conclusion, we found evidence that the position of two maternal trait distributions (elevation of the nest site and lay date), associated with the reproductive strategy of C. insculpta, reflect a combination of natural selection, physical constraints, and phenotypic plasticity. (C) 2004 The Linnean Society of London.
AB - Despite the importance of maternal effects in evolution, and knowledge of links among nest site choice, timing of nesting, offspring sex, and reproductive success in animals with environmental sex determination, these attributes have not been rigorously studied in a combined and natural I context. To address this need we studied the relationships between three maternal traits (nest site choice, lay date, and nest depth) and two fitness-related attributes of offspring (hatchling sex and embryonic survival) in the riverine turtle Carettochelys insculpta, a species with temperature-dependent sex determination, for four years. Predation and flooding were the major sources of embryonic mortality in 191 nests. Embryonic survival was influenced by both lay date and nest site choice: in one year when nesting began later than average, nests laid later and at lower elevations were destroyed by early wet season river rises. In other years early nesting precluded flood mortality. However, turtles did not nest at the highest available elevations, and a field experiment confirmed that turtles were constrained to nest at lower elevations where they could construct a nest chamber. The principal determinant of hatchling sex in 140 nests was lay date, which in turn was apparently related to the magnitude of the previous wet season(s). Clutches laid earlier in the season (a female's first clutch) produced mainly males, while later clutches (her second clutch) yielded mostly females, due to seasonal increases in air temperatures. Accordingly, later nesting produced female-biased hatchling sex ratios in 1996, while earlier nesting resulted in sex ratios near unity in the other years. However, all-female nests were more likely to be flooded than mixed-sex or all-male nests in years when nesting was late. In conclusion, we found evidence that the position of two maternal trait distributions (elevation of the nest site and lay date), associated with the reproductive strategy of C. insculpta, reflect a combination of natural selection, physical constraints, and phenotypic plasticity. (C) 2004 The Linnean Society of London.
KW - Carettochelys insculpta
KW - embryonic survival
KW - nest site choice
KW - reptile
KW - timing of reproduction
KW - NEST-SITE SELECTION
KW - PIG-NOSED TURTLE
KW - WET-DRY TROPICS
KW - CHELONIA-MYDAS NESTS
KW - CARETTOCHELYS-INSCULPTA
KW - CHRYSEMYS-PICTA
KW - CHELYDRA-SERPENTINA
KW - ADAPTIVE SIGNIFICANCE
KW - HATCHING SUCCESS
KW - CARETTA-CARETTA
UR - https://digitalcommons.usf.edu/fac_publications/3744
UR - https://doi.org/10.1111/j.1095-8312.2004.00250.x
M3 - Article
JO - Default journal
JF - Default journal
ER -