Access to abundant resources mitigates the effects of nutritional status on life history trade-offs: An Experimental Study on Burying Beetles

Individuals can adjust allocation strategies based on intrinsic and extrinsic factors. Variation in nutritional status during sexual maturation and resource acquisition during breeding may affect life history functions and trade-offs. However, it is unclear whether individuals can compensate for poor nutritional status during sexual maturation when resource acquisition becomes favorable during breeding. To investigate this, we simultaneously manipulated male nutritional status during sexual maturation and resource acquisition during breeding in a burying beetle (Nicrophorus vespilloides). We monitored the separate and interactive effects of these two factors on life history functions and trade-offs (somatic vs. reproductive investment, number vs. size of offspring). We found that poor nutritional status during sexual maturation negatively affects reproductive investment in adulthood, whereas access to abundant resources during breeding buffers against these effects. Poor-fed males mitigated the initial differences in nutritional status compared to well-fed males by feeding more from the carcass, and thus masking the long-term effects of nutritional status on the reproductive performance. They gained more weight but provided less care than well-fed males when breeding on a small carcass, whereas they gained more weight and provided a similar amount of care as well-fed males when breeding on a large carcass. In addition, nutritional status during sexual maturation had no significant effects on subsequent reproductive performance (larvae number and average larval mass). However, there were significant trade-offs between the number and size of offspring, suggesting that poor-fed males consumed more from the carcass, which in turn reduced the amount of food resources for their offspring. The results obtained for males are independent of female partner's efforts and compensation effects. Our findings demonstrated that although the nutritional environment experienced during sexual maturation may influence allocation strategies in adulthood, individuals can compensate for a poor start if resource acquisition becomes more favorable during subsequent breeding.