“Boys are smelly.” A classic phrase, passed on through generations. Its accuracy about human males is probably debatable, but in lemurs, smells are a huge part of their lives, and can be very telling. Can a smell even indicate if an unborn lemur is going to be a male or female? Researchers appear to have found a way to tell: the key is in the mother’s scent during pregnancy.

Ring-tailed lemurs are an iconic species, famous for their black and white beauty, and, for those not watching them from distance, their particularly pungent, musky smell. It is an aromatic cocktail of chemicals and pheromones, and conveys a vast amount of information to other lemurs within sniffing range.

In a new study, further analysis of these scents has built up a picture of the particular cocktail given off by females during pregnancy. It seems that if the female is carrying a baby boy, her aroma is far more simple, and contains fewer odour compounds. If the foetus is female, the mother’s hormone patterns are drastically different, say the authors, and this dramatically alters her scent during pregnancy.

Are boys smelly? Perhaps. But, in the case of Madagascar’s magnificent lemurs, it seems that it is a female baby that can cause her mother to give off a stronger, potentially more pungent aroma.



The above is based on materials provided by Duke University.

Crawford, J. & Drea, C. (2015). Baby on board: olfactory cues indicate pregnancy and foetal sex in a nonhuman primate. Biology Letters, DOI:10.1098/rsbl.2014.0831

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