Banded mongoose mothers have solved a problem that has eluded humans for ages: how to create a more just and equitable society. How do they do it? By giving birth at the same time.
Mothers in a banded mongoose colony give birth on the same night, thus creating a "veil of ignorance" over which pups in the communal creche are their own biological offspring. This means that they will take care of all pups instead of just their own.
A new experiment showed that inequality at birth as measured by weight is quickly solved as mongoose mothers allocated extra care to underweight pups that aren't biologically theirs:
In the new study, led by the universities of Exeter and Roehampton, half of the pregnant mothers in wild mongoose groups were regularly given extra food, leading to increased inequality in the birth weight of pups.
But after giving birth, well-fed mothers gave extra care to the smaller pups born to the unfed mothers—rather than their own pups—and the pup size differences quickly disappeared.
Dr. Harry Marshall, of the Department of Life Sciences at the University of Roehampton, said: "In most of the natural world, parents favor their own young.
"However, in banded mongooses, the evolution of remarkable birth synchrony has led to the unusual situation that mothers don't know which pups are their own, and therefore cannot choose to give them extra care.
"Our study shows that this ignorance leads to a fairer allocation of resources—in effect, a fairer society."
Image: Adrian Pingstone/Wikipedia
