Parental care buffers against effects of ambient temperature on offspring performance in an insect

Abstract

Understanding how animals respond to and cope with variation in ambient temperature is an important priority. The reason for this is that ambient temperature is a key component of the physical environment that influences offspring performance in a wide range of ectotherms and endotherms. Here, we investigate whether posthatching parental care provides a behavioral mechanism for buffering against the effects of ambient temperature on offspring in the burying beetle Nicrophorus vespilloides. We used a 3 × 2 factorial design where we manipulated ambient temperature (15, 20, or 25 °C) and parental care (presence or absence of a female parent after hatching). We found that the effect of ambient temperature on offspring performance was conditional upon the presence or absence of a caring female. Fewer larvae survived in the absence than in the presence of a caring female at 15 °C while there was no difference in larval survival at 20 and 25 °C. Our results show that parental care buffers against some of the detrimental effects of variation in ambient temperature on offspring. We suggest that posthatching parental care may buffer against such effects by creating a more benign environment or by boosting offspring resilience toward stressors. Our results have important implications for our understanding of the evolution of parental care because they suggest that the evolution of parental care could allow species to expand their geographical range to colonize areas with harsher climatic conditions than they otherwise would tolerate.

Contribution of males to brood care can compensate for their food consumption from a shared resource

“…Note that fewer larvae per brood survived in the 5 g switch experiment compared with the control experiment (Figure ). Many factors are known to influence offspring fitness, from biotic ones like competition with mites (Gasperin, Duarte, & Kilner, ) or quantity and quality of the food (Hopwood, Moore, & Royle, ; Rebar, Leggett, Aspinall, Duarte, & Kilner, ; Rozen, Engelmoer, & Smiseth, ) or abiotic ones like temperature (Grew, Ratz, Richardson, & Smiseth, ). However, since we kept environmental factors, such as temperature, light condition, soil properties, and food resources constant among the treatments, we presently have no explanation for the discrepancy in larval fitness between the control and the 5 g switch experiment.…”

“…However, the reason for this small effect might be that males continue to feed from the carrion resource in the posthatching phase, that is, after the switch. A recent study has also shown that uniparental female care is more efficient under lower ambient temperatures compared with standard laboratory conditions (Grew et al, ). It might very well be possible that also the effects of a second caring parent might become more evident when environmental conditions are less favorable for the developing larvae.…”

The Impact of Environmental Factors on the Efficacy of Chemical Communication in the Burying Beetle (Coleoptera: Silphidae)

“…It might, therefore, be possible that the beetles require a specific temperature for optimal development. In fact, a recent study found evidence that temperature has an effect on offspring number and fitness in N. vespilloides ( Grew et al 2019 ). Although soil temperature might influence pheromone transmission, it more probably has an effect on the prevailing number or activity of beetles and, therefore, males choosing to call on sites with warmer soil can attract more females.…”

“…The reason for the success of this species might lie in its elaborate parenting behavior. Parental care has been shown to buffer against environmental variation and alleviate or remove environmental hazards ( Smiseth et al 2012 , Grew et al 2019 ). Hence, species exhibiting parental care, such as burying beetles, are able to actively create a stable micro-environment in which offspring can thrive.…”

Temperature‐mediated plasticity in incubation schedules is unlikely to evolve to buffer embryos from climatic challenges in a seasonal songbird

“…The hypothesis that behavioural plasticity of parental care allows parents to mitigate the impacts of environmental challenges for developing offspring in real time, and can also evolve, requires three predictions to hold at the phenotypic level. First, plastic responses by parents must exist and serve to further buffer offspring from challenging environmental conditions (Grew et al., 2019; Van Buskirk, 2012). However, increasing parental investment in response to challenging conditions is not inevitable, because doing so can elevate the costs of care and reduce lifetime fitness (Conway & Martin, 2000a; Reid et al., 2000; Williams, 1996).…”