Parental care is predicted to evolve to mitigate harsh environments, thus adaptive plasticity of care may be an important response to our climate crisis. In biparental species, fitness costs may be reduced with plasticity of behavior among partners. We investigated this prediction with the burying beetle, Nicrophorus orbicollis, by exposing them to contrasting benign and harsh thermal environments. We found strong fitness costs under the harsh environment, but rather than select for more care, visualized selection was stabilizing. Examining different components of care revealed positive directional selection for direct care and strong stabilizing selection for indirect care, resulting in constrained evolutionary responses. Further, because males and females did not coordinate their investments, the potential for adaptive plasticity was not enhanced under biparental care. Females cared at capacity with or without male partners, while males with partners reduced direct care but maintained indirect care levels. Decision rules were not altered in different environments, suggesting no shift from sexual conflict to cooperation. We suggest that the potential for parenting to ameliorate the effects of our climate crisis may depend on the sex-specific evolutionary drivers of parental care, and that this may be best reflected in components of care.

Data were collected as described in Moss and Moore 2021. Briefly, we used a mixed factorial design in which social condition (uniparental or biparental) was measured as a within-subject factor and thermal environment (benign or harsh) was measured as a between-subject factor. Hence, individual males and females were observed in two independent trials. Data were filtered and analyzed in R, beginning with the removal of any trials that failed due to errors in setup and the flagging of repeated measures to control for breeding history. Data were then analyzed for evidence of fitness costs (using survival analysis and tests of variation in potential/realized reproductive rates), differences in selection (using standardized selection gradients), and variation in plasticity (using repeated measures ANOVAs and MANOVAs).

Behavioral_Exp_Data.xlsx is the Excel file of the data.

Behavioral_Exp_Data.csv is the csv file, used as input to the R script.

Behavioral_Exp_Analysis_-_DataDryad.R is the R script for analysis.