Changes in Female Body Mass during Parental Care: The Effects of Resource Quantity and Female Condition on Reproductive Phenotype

Due to high energetic costs of parental care, resource availability and energy stores play an integral role in species with parental care, and can have important implications for a female’s reproductive phenotype (i.e., timing, number, and size of offspring). These implications are especially important when females are constrained by resource availability, and as a result face a trade-off in energy allocation between self-maintenance and reproduction. Here, we investigate the impact of resource quantity and female condition on female reproductive phenotype in the burying beetle (Nicrophorus orbicollis). We found that female mass (an indicator of a female’s energy stores and overall investment towards reproduction or self-maintenance) was significantly higher in starved females independently of resource quantity. Specifically, all females increased mass by the same proportion in anticipation of parental care, but starved females maintained a significantly higher mass compared to controls following the onset of parental care. The timing of oviposition (i.e. first egg), number, and size of offspring did not differ between treatments. This indicates that starved females invest more in self-maintenance during reproduction without experiencing negative effects on current reproductive success