Bowerbirds entice females with illusory designs

Sydney - Male bowerbirds woo females by building 'artistic' bowers out of vegetation which is shaded by plants or trees that create an illusion of uniform décor.

The females tend to choose mates from those who produce the best illusion, suggests a new study led by John Endler, professor of evolutionary biology at the James Cook University.

After mating, the females go off to build a nest and raise young independently. “So the bower is nothing more than a complex visual signal to females and a mating place,” added Endler, according to a James Cook statement.

The research involved recording the geometric patterns of objects on the bower courts. “I placed motion activated solar powered video recorders next to the bowers and recorded the behaviour and numbers of matings by the bower owner males.”

The research was conducted over several months at Dreghorn Station, a cattle station. “I concluded that males who build bowers with more effective false visual perspective, as seen by females, had more matings,” Endler said.

“Bowerbirds are extremely interesting and intelligent birds, particularly the species I have spent most time on, the Great Bowerbird," he said.

Endler said males also regularly stole each other's bower decorations and destroyed each other's bowers, something he said was akin to politicians sniping at each other.