Food deprivation affects egg laying and maternal care but not offspring performance in a beetle

Abstract

Individuals vary with respect to their nutritional state and such variation is an important determinant of the amount of resources individuals allocate toward reproductive functions. Currently, we have a relatively poor understanding of the downstream consequences of food deprivation on different traits associated with reproduction. Here, we address this gap by investigating how food deprivation affected different traits across the breeding cycle in the burying beetle, Nicrophorus vespilloides; a species that breeds on carcasses of small vertebrates serving as food for both parents and offspring. We found that food-deprived females took longer to start egg laying than control females, which may allow them more time to feed from the carcass. There was no difference between food-deprived and control females in the number, size, laying pattern, or hatching success of eggs, suggesting that this delay allowed females to compensate for their poor initial state. However, food-deprived females spent less time providing care, suggesting that this compensation was incomplete. Finally, we found no evidence for negative effects of food deprivation on the offspring’s growth or survival, which is surprising given that food-deprived females took longer to initiate egg laying and provided less care to their offspring. Our results highlight that food deprivation can have complex effects on parental and offspring traits, and suggest that females face a trade-off between the benefits of mitigating downstream consequences of nutritional stress and the costs associated with delaying the start of reproduction.

Increased allocation to reproduction reduces future competitive ability in a burying beetle

“…Thus, access to resources whilst breeding will mitigate some of the energetic costs of reproduction and may even increase future reproductive success by boosting the condition of breeding individuals relative to non-breeders. In support of this, caring parents are often heavier at the end of reproduction (Creighton et al, 2009;Gray, Richardson, Ratz, & Smiseth, 2018;Pilakouta, Richardson, et al, 2016;Richardson, Ross, & Smiseth, 2019;. Furthermore, males that provide parental care are more attractive because access to carrion allows them to allocate more resources to sexual signalling (Chemnitz, Bagrii, Ayasse, & Steiger, 2017).…”

No evidence for increased fitness of offspring from multigenerational effects of parental size or natal carcass size in the burying beetle Nicrophorus marginatus

“…However, none of these studies investigated whether size related multigenerational effects affect offspring lifetime fitness. Two studies investigated the relationship between multigenerational effects and offspring survival but did not study their role in lifetime fitness of offspring [ 66 , 68 ], and our data suggest that longer lifespan does not necessarily contribute to increased number of offspring over a lifetime (i.e., fitness). In natural environments, number of successful reproductive bouts may be fewer than that in our non-competitive lab environment.…”

“…Multigenerational effects in burying beetles (genus: Nicrophorus) are well established [11,33,52,[65][66][67][68]. Most of these studies investigate the relationship between maternal size and offspring size [11,33,52,65,66,73].…”

“…Previous studies in burying beetles have demonstrated multigenerational effects on offspring body size. For example, larger offspring being produced on larger carcasses [ 33 , 65 ], larger mothers laying larger eggs, which hatch into larger offspring [ 11 ], young mothers producing smaller offspring [ 66 ], mothers producing smaller offspring when the male parent is present [ 52 ], mothers altering hormone concentration in eggs [ 67 ], and mothers changing egg laying and offspring care behaviors when deprived of food [ 68 ]. Body size of the parent and carcass size are dominant mechanisms through which multigenerational effects are transmitted in burying beetles.…”

Adjustment of egg laying by both hosts and intraspecific brood parasites in a beetle

“…This is because prior work shows that there are key differences between the egg laying behaviour of brood parasites and females that are in poor nutritional condition for other reasons. Firstly, there is no evidence that food‐deprived females extend their laying spread (Richardson et al, 2019). Secondly, unlike brood parasites, food‐deprived females delay the onset of egg laying to obtain sufficient nutrients from the carcass (Richardson et al, 2019).…”