Interaction Between Age and Individual Heterogeneity Shapes Breeding Probability in a Long-Lived Marine Ectotherm

Area of Science:

• Ecology
• Evolutionary Biology
• Animal Behavior

Background:

• Reproductive skipping is an adaptive strategy in iteroparous species, potentially enhancing survival and future reproductive potential.
• The influence of age on breeding probability is understudied in long-lived species, particularly marine turtles.

Purpose of the Study:

• To investigate the roles of age and individual quality in reproductive patterns of green turtles (Chelonia mydas).
• To examine age-related changes in breeding probability and survival in a long-lived marine ectotherm.

Main Methods:

• Utilized a 52-year dataset from captive green turtles.
• Employed a multi-event capture-mark-recapture framework to analyze breeding patterns.
• Assessed the impact of age, individual quality, and breeding experience on reproductive decisions.

Main Results:

• Individual quality and age were primary drivers of reproductive patterns; high-quality turtles remained breeders, while low-quality turtles became non-breeders, especially at older ages.
• An antagonistic relationship existed between age and breeding experience concerning the interval between breeding seasons.
• Evidence of actuarial senescence was found, but reproductive senescence was negligible, with females retaining high reproductive value.

Conclusions:

• Lifelong individual differences significantly shape life histories in long-lived species like green turtles, a factor often overlooked.
• Green turtles exhibit a life-history strategy where reproductive capacity is maintained into old age despite survival senescence.