Temperature Variation Regulates the Trade-Off Between Pre- and Post-Hatching Investment in a Burying Beetle

Understanding how organisms respond to temperature variation is essential for assessing and predicting their resilience and vulnerability to environmental and climate changes. Here, using a biparental care burying beetle (<i>Nicrophorus vespilloides</i>), we tested whether and how parental investment in carcass preparation and ambient temperature interact to influence subsequent parental care behaviour and reproductive success. We employed a 3 × 2 factorial experiment, manipulating the levels of parental investment in carcass preparation (Reduced, Control, and Elevated) and ambient temperatures (benign: 20 °C and harsh: 23 °C) in breeding pairs. We found the following: (1) Irrespective of ambient temperature, males in the Reduced group decreased their pre-hatching care. (2) Across all investment groups, both sexes under higher temperature reduced post-hatching care. (3) Carcass-preparation investment and ambient temperature interactively influenced reproductive success. Overall, the harsh temperature decreased reproductive success. Furthermore, beetle pairs experiencing reduced carcass-preparation investment produced fewer eggs and lighter broods, while those experiencing elevated carcass-preparation investment produced smaller and lighter broods. Our findings provide new insights into how temperature variation affects parental investment strategies and enhance our understanding of the phenotypic plasticity in reproductive strategies that animals employ to cope with climate change.