Maternal care shapes an aposematic display and provides lifelong protection against predators

Parental care can improve early offspring survival against predators by
providing protection and resources. However, we have little knowledge of
how its effects shape predator-prey interactions later in life. We
investigated this with the burying beetle Nicrophorus vespilloides, which
provides care for offspring and carries warning colouration to advertise
its chemical defences to predators. Warning displays by prey are selected
by predators for uniformity and to reliably advertise the extent to which
individuals are chemically defended. We investigated whether the strength
of the correlation between the conspicuousness of the warning display and
the potency of the chemical defences depends on levels of care received
during development by manipulating the level of maternal care received by
larvae and tracking the effects into adulthood. We found that individuals
who received limited care developed into smaller adults with less
conspicuous warning displays. The correlation between the visual display
and the chemical defence was also weaker when broods received little care
as larvae. We conclude that maternal care received by burying beetles
modulates the information content of aposematic defence: less care makes
signals less reliable. Our results further suggest that the prey’s social
environment could constrain the response to selection from predators on
warning signal reliability.