They have long been viewed as a symbol of fidelity and everlasting love. But swans are in fact cheating philanderers who regularly flee the nest for extramarital sex, Australian researchers revealed on Wednesday.
DNA testing has shown that one in six cygnets is the product of an illicit encounter, smashing the monogamous image of the birds.
Now researchers at the University of Melbourne’s zoology department are trying to establish how the females manage to slip away from their partners, who are renowned for being protective, to mate on the side.
”Swans have long been renowned as symbols of lifelong fidelity and devotion, but our recent work has shown that infidelity is rife among black swans,” said Raoul Mulder, whose team was busy on Wednesday fitting tracking devices to scores of swans.
Mulder said that DNA paternity testing had pointed to extramarital activity among swans but it remained unclear how the illicit encounters took place.
In an effort to learn more, up to 60 male swans at Melbourne’s Albert Park Lake are being fitted with a tiny microchip attached to their tail feathers.
The females, in turn, are being fitted with a miniature tracking device, known as a decoder.
”When a male and female copulate, the female’s decoder unit detects the microchip implanted in the male’s tail feathers, registering the male’s identity, as well as the time of copulation,” Mulder said.
”All mating events are logged onto the decoder unit, so that a complete record of her mating behaviour over several weeks can be downloaded when the swan is recaptured.”
Mulder said the study targeted black swans because they were large enough to wear the tracking device and were more common than their introduced white cousins.
As well as providing a snapshot of the sexual activity of swans, the research could reveal extremely sophisticated mating choices by the female birds, Mulder said.
”There are risks associated with mating with other birds so there must be some evolutionary benefits,” Mulder told Agence France-Presse.
The study could point to ways in which females try to ensure the fitness of their offspring by seeking out the superior genes of another mating partner, he added.
The three-year, Aus$200 000 ($149 000) study is funded by a
grant from the Australian Research Council. – AFP
