The effect of experimental warming on reproductive performance and parental care in the burying beetle Nicrophorus nepalensis

Abstract

Rising temperatures can adversely affect parental care and reproductive performance across a range of taxa. However, the warming impact is contingent upon understanding how temperature affects the spectrum of parental behaviours and their interplay. Here, we assessed how temperature affects parental care and reproductive success in the burying beetle, Nicrophorus nepalensis, which exhibits complex parental care behaviours. We exposed breeding pairs of N. nepalensis, to three temperature regimes (18°C, 20°C and 22°C) and assessed changes in parental care, and the subsequent development and growth of their offspring. Our findings show that 22°C disrupts carcass nest building by the parents and results in smaller clutches. Moreover, no eggs successfully hatched in the 22°C treatment. A milder increase to 20°C did not affect the hatching rate but resulted in smaller broods and lighter offspring, even when considering brood size, suggesting a change in post-hatching care quality. Our research suggests that warming may weakly affect parental care but has strong detrimental effects on offspring performance. These findings highlight the necessity of investigating the effect of ambient temperature across a diversity of traits and behaviours and across a range of life-history stages to fully assess species vulnerability in the face of future climate change.

Keywords: climate change; life-history traits; nest construction; reproductive success.

Figure 1.

The effect of temperature treatments on parental behaviour, quantified from (a) the proportion of carcasses prepared and (b) the time until carcass preparation. Individual data were pointed with a jitter effect to prevent overlap. The letters denote non-significant differences among temperature treatments (Tukey honestly significant difference (HSD) tests).

Figure 2.

The effect of temperature treatments on the development and growth of larvae, as evidenced from (a) the number of days until the first egg is laid, (b) the number of days until the first larva hatched and (c) the number of days until larval dispersal. Individual data were pointed with a jitter effect to prevent overlap. Different letters denote significant differences among temperature treatments (Tukey HSD tests).

Figure 3.

The effect of temperature treatments on the reproductive performance measured as (a) clutch size, (b) brood size and (c) brood mass, whereas (d) the averaged larval mass negatively correlated with brood size. Individual data were pointed with a jitter effect to prevent overlap. Lines are statistically significant relationships predicted from GLMMs, whereas shaded areas represent 95% confidence intervals. Different letters denote significant differences among temperature treatments (Tukey HSD tests).