Ak. Eggert et Jk. Muller, Timing of oviposition and reproductive skew in cobreeding female burying beetles (Nicrophorus vespilloides), BEH ECOLOGY, 11(4), 2000, pp. 357-366
Burying beetles (genus Nicrophorus) are known for their elaborate parental
care. Two or more conspecific females may reproduce on the same carcass, es
pecially when the carcass is large. Here we present the results of experime
nts in which we observed patterns of larval hatching and parental care in u
nmanipulated cobreeders, manipulated hatching synchrony between cobreeders,
and compared patterns of oviposition in cobreeding and single females. Our
results show that in these cobreeding associations, one of the females may
or may not monopolize the carcass during the period of larval hatching. We
present evidence that in either case, infanticide based on temporal cues c
onstitutes an important proximate mechanism underlying the observed reducti
on in average reproductive success in cobreeding females. Females with high
er synchrony (i.e., greater overlap between their oviposition patterns) pro
duce larger broods with lower reproductive skew. Cobreeding females oviposi
t later and less synchronously than single breeders. Such delayed ovipositi
on may reduce the risk that a female's larvae fall victim to cannibalistic
acts committed by her cobreeder or maximize her own opportunity to selectiv
ely kill her cobreeder's larvae.