Burying beetles are known for their macabre lifestyles: A breeding pair buries the carcass of a small creature, strips it of fur, and coats it with an antibacterial secretion to make a nest for its larvae. Once the eggs hatch, the carcass becomes a family feast.
However, what may seem like a grisly practice to you is actually the height of good parenting for the burying beetle. Unfortunately, a doting father may pay the price for its high-quality care and die an early death, according to new research from the University of Cambridge. The findings are published in the journal eLife.
A beetle father can be sent to an early grave by a negligent mother if she shirks her duties and leaves him to pick up the slack. In doing so, he sacrifices his own longevity for the benefit of his larvae. The same does not hold true for mothers: Their lifespans remain the same whether or not they are high-quality parents. The reason for this discrepancy is unclear.
“Parents obviously play a huge role in determining the characteristics of their offspring,” said lead researcher Rebecca Kilner, a zoology professor from the University of Cambridge, in a statement. “The aim of our study was to investigate non-genetic ways that parents achieve this.”
The study explores how these non-genetic factors influence evolution and animal behavior. Larvae that receive bad parenting from both their mother and father become less successful parents themselves, raising smaller broods and suffering greater mortality. High-quality parents produce larger broods and their offspring become similarly good parents.
A possible pitfall for the offspring of devoted parents, however, is that they can be exploited once they mature and reach mating age. If a high-quality father pairs with a low-quality mother, the father must exert more effort, ultimately paying the price for his poor choice in partner – a significantly shorter life.
“How these differences in lifespan translate into reproductive success in nature is unknown,” Kilner adds, “but since males might mate with multiple females in 8 days, the effects are unlikely to be trivial.”