Does sex-ratio selection influence nest-site choice in a reptile with temperature-dependent sex determination?

Mitchell, Timothy S.; Maciel, Jessica A.; Janzen, Fredric J.

doi:10.1098/rspb.2013.2460

Cited by 48 publications

(54 citation statements)

References 35 publications

(63 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In a small-bodied freshwater species, Refsnider et al (2013b) concluded that maternal adjustment of nest depth is unlikely to significantly improve offspring sex ratio skews, suggesting instead that shifts in components of nest site choice, rather than nest depth, may be a more profitable maternal response. Indeed, in comparing painted turtle (Chrysemys picta) neonates from maternally selected nest sites with those from randomly selected nest sites, Mitchell et al (2013) recently presented evidence that sex ratio selection appears to be an important component of nest site choice in reptiles with TSD, supporting theories that behavioral plasticity will be a key factor in ensuring the reproductive success of reptiles. Given that marine turtles exhibit natal philopatry and site fidelity, the choices available to a nesting female when choosing a nest site are limited (Lutz et al 2003;Hawkes et al 2007).…”

Section: Discussionmentioning

confidence: 89%

The Effect of Thermal Variance on the Phenotype of Marine Turtle Offspring

Horne¹,

Fuller²,

Godley³

et al. 2014

Physiological and Biochemical Zoology

View full text Add to dashboard Cite

Temperature can have a profound effect on the phenotype of reptilian offspring, yet the bulk of current research considers the effects of constant incubation temperatures on offspring morphology, with few studies examining the natural thermal variance that occurs in the wild. Over two consecutive nesting seasons, we placed temperature data loggers in 57 naturally incubating clutches of loggerhead sea turtles Caretta caretta and found that greater diel thermal variance during incubation significantly reduced offspring mass, potentially reducing survival of hatchlings during their journey from the nest to offshore waters and beyond. With predicted scenarios of climate change, behavioral plasticity in nest site selection may be key for the survival of ectothermic species, particularly those with temperature-dependent sex determination.

show abstract

Section: Discussionmentioning

confidence: 89%

The Effect of Thermal Variance on the Phenotype of Marine Turtle Offspring

Horne¹,

Fuller²,

Godley³

et al. 2014

Physiological and Biochemical Zoology

View full text Add to dashboard Cite

show abstract

“…Using Gap Light Analyzer software (ver. 2.0; Frazer et al 1999), we estimated canopy cover (% shade) and incident solar radiation (MJ m 22 day 21 ) over the course of development for each nest from these photographs (Doody et al 2006;Mitchell et al 2013). Nest predation is high at our site, so we placed a metal screen over each nest (a 1 # 1-cm mesh aluminum hardware cloth, staked to the ground) to guard nests from predators.…”

Section: Study Speciesmentioning

confidence: 99%

Reptile Embryos Lack the Opportunity to Thermoregulate by Moving within the Egg

Telemeco

Gangloff

Cordero

et al. 2016

The American Naturalist

Self Cite

View full text Add to dashboard Cite

Historically, egg-bound reptile embryos were thought to passively thermoconform to the nest environment. However, recent observations of thermal taxis by embryos of multiple reptile species have led to the widely discussed hypothesis that embryos behaviorally thermoregulate. Because temperature affects development, such thermoregulation could allow embryos to control their fate far more than historically assumed. We assessed the opportunity for embryos to behaviorally thermoregulate in nature by examining thermal gradients within natural nests and eggs of the common snapping turtle (Chelydra serpentina; which displays embryonic thermal taxis) and by simulating thermal gradients within nests across a range of nest depths, egg sizes, and soil types. We observed little spatial thermal variation within nests, and thermal gradients were poorly transferred to eggs. Furthermore, thermal gradients sufficiently large and constant for behavioral thermoregulation were not predicted to occur in our simulations. Gradients of biologically relevant magnitude have limited global occurrence and reverse direction twice daily when they do exist, which is substantially faster than embryos can shift position within the egg. Our results imply that reptile embryos will rarely, if ever, have the opportunity to behaviorally thermoregulate by moving within the egg. We suggest that embryonic thermal taxis instead represents a play behavior, which may be adaptive or selectively neutral, and results from the mechanisms for behavioral thermoregulation in free-living stages coming online prior to hatching. KeywordsChelydra serpentina, microclim, nest, play, soil, snapping turtle, temperature Disciplines Ecology and Evolutionary Biology | Evolution | Population Biology CommentsThis article is from The American Naturalist 188 (2016) abstract: Historically, egg-bound reptile embryos were thought to passively thermoconform to the nest environment. However, recent observations of thermal taxis by embryos of multiple reptile species have led to the widely discussed hypothesis that embryos behaviorally thermoregulate. Because temperature affects development, such thermoregulation could allow embryos to control their fate far more than historically assumed. We assessed the opportunity for embryos to behaviorally thermoregulate in nature by examining thermal gradients within natural nests and eggs of the common snapping turtle (Chelydra serpentina; which displays embryonic thermal taxis) and by simulating thermal gradients within nests across a range of nest depths, egg sizes, and soil types. We observed little spatial thermal variation within nests, and thermal gradients were poorly transferred to eggs. Furthermore, thermal gradients sufficiently large and constant for behavioral thermoregulation were not predicted to occur in our simulations. Gradients of biologically relevant magnitude have limited global occurrence and reverse direction twice daily when they do exist, which is substantially faster than embryos can shift position within the...

show abstract

“…For oviparous vertebrates, the choice of where to lay one's eggs is the final and most important choice for enhancing offspring survival, and therefore fitness, as most fish, amphibians and reptiles lack parental care after oviposition [51]. Such choices are increasingly understood to be quite sophisticated; for example, mosquitoes can not only discriminate predator presence but quantify varying degrees of risk [25] and turtles appear to choose oviposition sites in order to balance offspring sex ratio [52]. However, the ways that females make decisions when facing conflicting indicators of offspring survival and development is less well understood (but see [38,39]).…”

Section: Discussionmentioning

confidence: 99%

Oviposition site choice under conflicting risks demonstrates that aquatic predators drive terrestrial egg-laying

Touchon

Worley

2015

Proc. R. Soc. B.

View full text Add to dashboard Cite

Laying eggs out of water was crucial to the transition to land and has evolved repeatedly in multiple animal phyla. However, testing hypotheses about this transition has been difficult because extant species only breed in one environment. The pantless treefrog, Dendropsophus ebraccatus, makes such tests possible because they lay both aquatic and arboreal eggs. Here, we test the oviposition site choices of D. ebraccatus under conflicting risks of arboreal egg desiccation and aquatic egg predation, thereby estimating the relative importance of each selective agent on reproduction. We also measured discrimination between habitats with and without predators and development of naturally laid aquatic and arboreal eggs. Aquatic embryos in nature developed faster than arboreal embryos, implying no cost to aquatic egg laying. In choice tests, D. ebraccatus avoided habitats with fish, showing that they can detect aquatic egg predators. Most importantly, D. ebraccatus laid most eggs in the water when faced with only desiccation risk, but switched to laying eggs arboreally when desiccation risk and aquatic predators were both present. This provides the first experimental evidence to our knowledge that aquatic predation risk influences non-aquatic oviposition and strongly supports the hypothesis that it was a driver of the evolution of terrestrial reproduction.

show abstract

Does sex-ratio selection influence nest-site choice in a reptile with temperature-dependent sex determination?

Cited by 48 publications

References 35 publications

The Effect of Thermal Variance on the Phenotype of Marine Turtle Offspring

The Effect of Thermal Variance on the Phenotype of Marine Turtle Offspring

Reptile Embryos Lack the Opportunity to Thermoregulate by Moving within the Egg

Oviposition site choice under conflicting risks demonstrates that aquatic predators drive terrestrial egg-laying

Contact Info

Product

Resources

About