Male animals can smell virginity

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London: Many males are able to 'smell' whether a potential female partner is a virgin, and if not, how many times she has mated, according to a new study on animals.

Scientists at the University of Western Australia have been trying to discover how important smell may be to courting animals, reports the BBC.

They found that male brown lemmings (Lemmus sibiricus) much prefer the odour of virgin females to that of females that have just copulated.

It seems that the males use scent as an indicator, and that virgin females smell very different from those that have had multiple partners because they produce very different chemicals.

Even the insect world is heady with the aromas of sex. Mated female leaf miner flies (Agromyza frontella), for example, express their status by producing lower levels of an aromatic chemical called 3,7-dimethylnonadecane than unmated females.

There have been few direct studies of the strange effects of odour of sexual behaviour. Most have been based on insects, said Melissa Thomas of the University of Western Australia, Crawley, who has published the latest review.

Animals, it seems, secretly waft the scent of their sexual status in three ways. First, after meeting, female animals may produce a scent that repels other males. Second, females may actually stop emitting male-enticing pheromones after they have mated. This occurs in the gypsy moth, so the pregnant female can flutter away without being pestered by other amorous males (Lymantria dispar).

Lastly, males can actually apply chemicals to females while mating with them-sneakily rubbing on perfumes that deter rivals from later mating with 'their' female.

When fruit flies (Drosophila melanogaster) mate, the male transfers a chemical called 7-tricosene to the females. This is the only known example of pheromones being passed between the sexes by simple bodily contact.

In some moths and butterflies, for example, pheromones in the male's ejaculate 'switch off' the calling behaviour of receptive females. While a chemical in the male fruitfly ejaculate renders the females less attractive to new suitors.

The findings have been published in the journal Biological Reviews.