Data from: Full compensation of parental care after partner loss in an annelid

In species with biparental care, each parent would benefit by exploiting
its partner and reduce its investment over offspring care. The conflict is
especially apparent when one parent deserts or reduces its investment,
forcing the remaining parent to either abandon the brood or compensate for
the loss of partner-care effort; however, compensation is expected to be
partial for the evolutionary stability of biparental care. We investigated
the level of parental care compensation in the simultaneously
hermaphroditic annelid worm, Ophryotrocha diadema, where both parents care
for egg clutches. We removed one parent and found that widowed parents
fully compensated for the loss of their partner; the number of scan
observations widows spent in clutch attendance was statistically
equivalent to that of paired parents. Consistently, individually, widowed
parents attended their clutch significantly more often than focal worms
among paired parents. We discuss how full compensation can be compatible
with evolutionary stability of biparental care in a rare species with
sparse population and whose adaptations suggest that mate encounter might
be rare. In this condition, nest attendance might be valuable as it
promotes clutch protection from predators as well as mate encounters thus
mitigating the conflict of interests over parental care.