Harsh environmental conditions in form of low food availability for both offspring and parents alike can affect breeding behaviour and success. There has been evidence that food-scarce environments can induce competition between family members, and this might be intensified when parents are caring as a pair and not alone. On the other hand, it is possible that a harsh, food-poor environment could also promote cooperative behaviours within a family, leading, for example, to the higher breeding success of pairs than of single parents. We studied the influence of a harsh nutritional environment on the fitness outcome of a family living in the burying beetle Nicrophorus vespilloides. These beetles use vertebrate carcasses for reproduction. We manipulated food availability on two levels: before and during breeding. We then compared the effect of these manipulations in broods with either single females or biparentally breeding males and females. We show that pairs of beetles that experienced a food-poor environment before breeding consumed a higher quantity of the carcass than well-fed pairs or single females. Nevertheless, they were more successful in raising a brood with higher larval survival compared to pairs that did not experience a food shortage before breeding. We also show that food availability during breeding and social condition had independent effects on the mass of the broods raised, with lighter broods in biparental families than in uniparental ones and on smaller carcasses. Our study thus indicates that a harsh nutritional environment can increase both cooperative as well as competitive interactions between family members. Moreover, our results suggest that it can either hamper or drive the formation of a family because parents choose to restrain reproductive investment in a current brood or are encouraged to breed in a food-poor environment, depending on former experiences and their own nutritional status.

Unprocessed data from "Harsh nutritional environment has positive and negative consequences for family living in a burying beetle." Methods of data collection are described in the Manuscript.

Excel file with one spreadsheet. The spreadsheet contains data on male and female nutritional status, pronotum width, body mass at different time points, carcass mass at different time points, number of larvae raised, total brood mass, clutch size, and larval survival rate.

ID    - Individual Beetle ID

Group - Experimental Group

nutritional_condition - food-deprived vs. well-fed, induced by either a seven-day starvation before carcass receival or normal feeding regime

social condition - biparental vs. uniparental

carcass_category - 2.5g carcass vs. 5 g carcass

carcass_initial - exact measured value of carcass mass at carcass receival

carcass_48h - exact measured value of carcass mass after 48h of carcass preparation

carcass_end - exact measured value of carcass mass at larval dispersal

male_weight_before_manipulation - exact measured value of male body mass before starvation/non-starvation period (n/a values in uniparental female broods without males)

male_weight_after_manipulation - exact measured value of male body mass after starvation/non-starvation period (n/a values in uniparental female broods without males)

male_weight_after_48h_at_carcass - exact measured value of male body mass 48h after carcass receival (n/a values in uniparental female broods without males)

male_weight_end - exact measured value of male body mass at the end of brood care (n/a values in uniparental female broods without males)

pronotum_male - measured size of the male pronotum with Profiscale Precise PS 7 215 digital callipers to the nearest 0.01 mm (n/a values in uniparental female broods without males)

female_weight_before_manipulation - exact measured value of female body mass before starvation/non-starvation period

female_weight_after_manipulation - exact measured value of female body mass after starvation/non-starvation period

female_weight_after_48h_at_carcass -  exact measured value of female body mass 48h after carcass receival

female_weight_end - exact measured value of female body mass at the end of brood care (n/a: missing data point)

Pronotum_female - measured size of the male pronotum with Profiscale Precise PS 7 215 digital callipers to the nearest 0.01 mm

number_of_eggs - e.g. clutch size; number of eggs counted in a brood before hatching of larvae

number_of_larvae - number if larvae that survived until dispersal (n/a: broods with zero eggs)

broodmass - sum of all larval weights at dispersal in one brood (n/a: broods without eggs and without surviving larvae)

eggs yes_no - binary parameter: 0 if no eggs were laid at all, 1 if at least one egg was laid 

percentage - larval survival rate: calculated as the number of larvae that survived until dispersal in relation to the number of eggs initially laid. (n/a: broods with zero eggs)