Great bowerbirds are known for their dramatic mating displays and elaborate constructions. Now researchers have determined males of this crafty species build staged scenes that make themselves look larger or smaller than they actually are.
As a result, the scientists believe great bowerbirds are the first known non-human animals that create scenes with altered visual perspectives for viewing by other individuals. In this case, those other individuals are female great bowerbirds seeking mates.
Architects, set designers and artists frequently employ the technique when creating certain paintings, gardens, amusement parks and other constructions that feature optical illusions. But we're relatively new at this.
"Bowerbirds have been doing it longer than we have," lead author John Endler told Discovery News. "Good human perspective didn't get started until the 15th century."
Endler, a professor of sensory ecology and evolution at Deakin University, and colleagues Lorna Endler and Natalie Doerr studied great bowerbird bowers in Queensland, Australia.
Each male-made bower consists of an avenue -- two rows of tightly packed sticks with a stick floor -- that opens onto a court. The court functions as a stage where the male displays for females.
The avenue ensures females can only see the court from one viewing angle. Males carefully line their courts with pebbles, bones and shells, such that the absolute size of these objects increases with distance from the avenue entrance and the female viewers.
This design could lead females to "perceive the court as smaller than it is and therefore perhaps perceive the male as larger than he is," according to Endler.
The male then tries to wow the female with his show.
Read more at Discovery News
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