Mongooses solve inequality problem

https://www.eurekalert.org/pub_releases/2021-06/uoe-msi062121.php

 

News Release 23-Jun-2021
University of Exeter

A fair society has evolved in banded mongooses because parents don't know which pups are their own, new research shows.

Mothers in banded mongoose groups all give birth on the same night, creating a "veil of ignorance" over parentage in their communal crèche of pups.

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.


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Professor Michael Cant, of the University of Exeter said: "We predicted that a 'veil of ignorance' would cause females to focus their care on the pups most in need - and this is what we found.

"Those most able to help offer it to the most needy, and in doing so minimise the risk that their own offspring will face a disadvantage.

"This redistributive form of care 'levelled up' initial size disparities, and equalised the chances of pups surviving to adulthood.

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