Abstract
Two models have been proposed to explain age-related changes in reproductive performance. State-dependent models predict that reproductive effort depends on the magnitude of surplus energy reserves, which often varies with age. Contrary to this prediction, there was no significant effect of starvation on the outcome of contests for carcasses by female Nicrophorus orbicollis despite weight loss by starved females relative to controls. The residual reproductive value (RRV) model predicts that individuals adjust their current reproductive effort based on potential for future reproduction. Younger adults are predicted to restrain reproductive effort because they are less willing to risk their potentially longer reproductive careers. This model was tested empirically for several components of reproduction. Age was found to be strongly correlated with dominance when two similarly sized females discovered a carcass on the same day. Age also had a small positive effect on egg mass and was positively correlated with ovipositing at least one egg. Age did not affect nesting performance (the degree of carcass burial or the value of a prepared carcass for another female). Age also had no effect on fecundity when a female bred alone but was an important factor when two females were in direct competition. Changing RRV related to aging appears to be a robust determinant of contest outcomes in burying beetles, but effects on other components of reproductive effort in the present and previous studies are more variable, perhaps because of effects of changing state.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.