HomeUncategorizedAnimal behaviour: Feminine mice launch banana-scented urine when pregnant to discourage males

Animal behaviour: Feminine mice launch banana-scented urine when pregnant to discourage males


Pregnant and lactating feminine mice launch a banana-smelling chemical of their urine that’s thought to emphasize out males so that they don’t commit infanticide


20 Could 2022

A pregnant harvest mouse (Micromys minutus) and a pup: females will combat to guard their younger, and use their urine to remind males of the very fact

Klein and Hubert/NaturePL

Feminine mice which might be closely pregnant or have lately given delivery produce a banana-smelling chemical of their urine that stresses out males, presumably to cease them from killing their pups.

Jeffrey Mogil at McGill College in Montreal and his colleagues found this behaviour accidentally. “We had been doing experiments with pregnant feminine mice and seen that male mice that had been getting used for different experiments in the identical room had been appearing a bit loopy,” he says.

To discover additional, they examined the stress ranges of male mice once they had been positioned in a cage close to that of one other male mouse or a feminine that was both not pregnant, newly pregnant, closely pregnant, had lately given delivery and was lactating, or had given delivery up to now and was not lactating.

The male mice confirmed diminished ache sensitivity and elevated corticosteroid ranges – that are each indicators of stress – once they had been caged close to feminine mice that had been closely pregnant or lactating, however not once they had been close to the opposite mice.

The researchers found that this was as a result of closely pregnant and lactating females produced a chemical of their urine known as amyl acetate, which smells of bananas. This wafted into the males’ close by cages and made them pressured once they sniffed it.

Simply exposing the males to this chemical alone made them pressured, even when there have been no pregnant or lactating females round.

Females in all probability launch this chemical when they’re about to have pups or have simply had them to let males know, “when you come any nearer, I’ll beat the crap out of you”, says Mogil.

It is because male mice attempt to kill pups which were fathered by different males, he says.

Consistent with this, pregnant and lactating females left extra urine marks once they had been uncovered to stranger males than once they had been uncovered to the daddy of their pups.

“Females are identified to unleash severe aggression if males attempt to assault their pups so we expect that when males odor this chemical of their urine, the prospect that there is perhaps a combat causes their stress response,” says Mogil.

The researchers didn’t check if sniffing this chemical did in actual fact cease males from killing pups as a result of it might be unethical to conduct that form of experiment, says Mogil.

The findings have implications for different mouse analysis since some scientists might unwittingly be utilizing pressured mice of their experiments in the event that they home male mice close to pregnant females, says Mogil. This may very well be one purpose why completely different labs typically get completely different outcomes from the identical experiments, he says. “It’s one thing we have to pay extra consideration to.”

Journal reference: Science Advances, DOI: 10.1126/sciadv.abi9366

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