Infant mongooses rely on adults to escort them as they learn to forage. A new study from the University of Exeter reports that adult mongooses show no preference for their own offspring when choosing a pup to escort, and the authors suggest they may not be able to tell their own kin apart.
This is a surprising finding, because evolutionary theory predicts that adults should try to help their own offspring, with whom they share the most genes. We might expect to see that adult mongooses offer more care to their own pups – but that’s not what the study found. Instead, adults paired with pups to escort at random.
Revealing their identity might put pups at risk of aggression from other members of the pack, so Mongooses evolved to conceal their identity from adults in order to maximise the help their receive from the whole pack.
“In most species we would expect mothers to target care at their own offspring, but mongooses seem unable to do this,” said Dr Emma Vitikainen from the Centre for Ecology and Conservation in Cornwall.
“We think this is because mothers synchronise birth to the same day, and pups may have evolved to conceal their identity.”
While adults showed no pattern of pairing with pups that were more closely related to them, once paired, male mongooses tended to spend longer escorting pups that they were more closely related to. However, the authors point out that this doesn’t necessarily mean they know the pup is related to them – they may simply tend to pair with related pups for longer because they have similar foraging habits (because they share genes).
Based on these results, it seems likely that adult mongooses are unable to tell which pups are their own, which may help ensure that all pups get the same quality of care, and avoid aggression from unrelated pack members.
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Usually I really like your write-ups of published literature. But this time, the paper is misinterpreted and words put into “its” mouth. Nowhere do the authors conclude that pups conceal or are selected to conceal their identity. The authors say that their results simply say that either the adults cannot tell which pup is their offspring OR they do not use that information, and that the effect may be to decrease within group aggression. They go so far as to suggest between group selection, which is the real substantive inference one can make. My restatement: groups in which adult caretakers are not selective based on parentage nor aggressive in relation to kinship raise more babies. The message that there is a sex bias to escort-pup pairings is not mentioned in this writeup, although it is an interesting important result flagged in the title.
Finally, the notion that males might escort longer if related to the pup because shared genes give rise to shared foraging patterns is offered as a single, vague suggestion among others, to explain that. The discussion given to that issue more clearly emphasizes the worth of pups to the group, especially a relationship between relatedness, group size and pup value as recruits. These ideas again get back to group-level selective forces.
In summary, this write up of a very interesting paper is biased in not acknowledging anything beyond simple (‘naive” in the authors’ words) kin selection, re-weighting the authors’ own discussion, putting words in their paper, and not giving credence to their suggested group-level selection. I would be happy to discuss this further with Dr. Asher, but I am disappointed in this particular science news story.
Hi Anne,
Thanks for your comments. I’m sorry to hear you feel my summary of the paper and it’s interpretations of the data was incomplete. I do not believe, however, that I have put words in the authors’ (or the paper’s) mouths. The notion that the pups are concealing their identity comes straight from the press release on the University of Exeter website – which I quoted in the blog post above. On behalf of the authors Dr Emma Vitikainen said, “We think this is because mothers synchronise birth to the same day, and pups may have evolved to conceal their identity”. I therefore felt that my short summary covered the main interpretation of the data presented by the authors, along with some of the interesting aspects of the data. The sex-bias is an interesting feature, I’m sorry that I didn’t find time to cover it in my article.
I hope you’ll enjoy my next blog post more, and thanks for taking the time to comment!
Claire
very interesting :o) thanks for the article, dOnnabud