DOI: 10.5061/dryad.h18931zh5
title: Increased allocation to reproduction reduces future competitive ability in a burying beetle

description: 1. The existence of a trade-off between current and future reproduction is
 a fundamental prediction of life-history theory. Support for this
 prediction comes from brood size manipulations, showing that caring for
 enlarged broods often reduces the parent’s future survival or fecundity.
 However, in many species, individuals must invest in competing for the
 resources required for future reproduction. Thus, a neglected aspect of
 this trade-off is that increased allocation to current reproduction may
 reduce an individual’s future competitive ability. 2. We tested this
 prediction in the burying beetle, Nicrophorus vespilloides, a species
 where parents care for their offspring and where there is fierce
 competition for resources used for breeding. 3. We manipulated
 reproductive effort by providing females with either a small brood of 10
 larvae or a large brood of 40 larvae and compared the ability of these
 females, and virgin females that had no prior access to a carcass, to
 compete for a second carcass against a virgin competitor. 4. We found that
 increased allocation to current reproduction reduced future competitive
 ability, as females that had cared for a small brood were more successful
 when competing for a second carcass against a virgin competitor than
 females that had cared for a large brood. In addition, the costs of
 reproduction were offset by the benefits of feeding from the carcass
 during an initial breeding attempt, as females that had cared for a small
 brood were better competitors than virgin females that had no prior access
 to a carcass, whilst females that had cared for a large brood were similar
 in competitive ability to virgin females. 5. Our results add to our
 understanding of the trade-off between current and future reproduction by
 showing that this trade-off can manifest through differences in future
 competitive ability and that direct benefits of reproduction can offset
 some of these costs. 16-Apr-2020
description: <b>Read me for “Data from
 RichardsonStephensSmiseth_JournalofAnimalEcology.csv” </b>
 This data file consists of a comma separated values spreadsheet
 (.csv), which provides data for the effects of allocation to reproduction
 via brood size manipulation on future competitive ability in contests for
 a carcass. Each line in the spreadsheet represents an individual,
 experimental female.  <b>female_id –
 </b>individual ID of the female. 
 <b>eclosion – </b>date of eclosion. 
 <b>death – </b>date of death. 
 <b>lifespan – </b>number of days lived from eclosion
 to death.  <b>treatment_code –
 </b>experimental treatment (control = no breeding attempt, ten =
 brood of ten larvae, forty = brood of forty larvae). 
 <b>won – </b>outcome of the contest (Y = female won,
 N = female lost, NA = unclear).  <b>outcome_clear
 – </b>was the outcome of the contest clear? (Y = yes, N =
 no).  <b>size – </b>size of the female,
 measured as pronotum width (mm). 
 <b>competitor_size – </b>size of the virgin female
 competitor measured as pronotum width (mm). 
 <b>size_difference – </b>absolute difference in size
 between focal female and her competitor (mm). 
 <b>brood_size – </b>number of larvae in the
 experimental brood at dispersal.  <b>dot –
 </b>number and placement of identifying marks (1 or 2 = number of
 dots, L or R = left or right elytra). 
 <b>female_pre_mass – </b>female mass prior to initial
 reproductive attempt (g).  <b>female_post_mass –
 </b>female mass after initial reproductive attempt (g). 
 <b>female_mass_change – </b>female mass change during
 initial reproductive attempt (g). 
 <b>brood_mass_pre – </b>mass of the brood of larvae
 when cross fostered and given to the female (g). 
 <b>brood_mass_post – </b>mass of the brood of larvae
 at dispersal from the carcass (g). 
 <b>breeding_carcass_mass – </b>mass of the mouse
 carcass used for breeding (g). 
 <b>competition_carcass_mass – </b>mass of the mouse
 carcass females competed for (g).