Nicky Phillips and Deborah Smith July 05, 2012
Sydney may have its fair share of drag queens, but it is Sydney Harbour's unseen cross dressers who really steal the show.
Scientists have discovered mourning cuttlefish can simultaneously display both male and female skin colours, a rather unconventional courting strategy that attempts to seduce a nearby female while deceiving male rivals.
Researchers from Macquarie University first noticed the unusual behaviour, where a male will colour half his body with the typical male skin pattern of pulsating stripes and the other half with the mottled camouflage characteristic of females, while observing the species at Manly Aquarium.
The team then spent six years photographing the bizarre mating tactic at various sites around Sydney Harbour and found close to 40 per cent of groups with males employed the cunning trick.
The research leader, Culum Brown, said males were strategic about changing their skin colour, and only performed the trick when in the presence of a single female and a single male rival.
"One of the amazing things is they are very specific about when they employ the tactic," said Dr Brown, an associate professor at Macquarie University.
Males were unlikely to change colour when there was a good chance their deception would be discovered, the researchers found.
On two occasions the team witnessed deceptive males mating with females, which suggested the technique was, at times, successful.
"The old adage that cheaters never prosper is far from applicable in the animal kingdom," wrote the authors, who published their findings in the Royal Society journal Biology Letters. As mourning cuttlefish colonies, which are found along the east coast of Australia, are male dominant, they must compete for females by guarding their mates, displacing rivals and interrupting courtships.
"In this context, natural selection should strongly favour any tactic that reduces the probability of courtship interruption and thereby maximises male reproductive success," they said.
The ability of cuttlefish to change their skin colour was both dramatic and rapid and used for camouflage and communication, the researchers said.