"The visual display includes his presenting his expanded bluish-purple nuchal crest waved at the female, and then turning around and waving a colored object towards the female," he said. "This is often accompanied by a strutting walk around the avenue."
If impressed, the female will mate with the male right on "stage."
For the study, published in Current Biology, Endler and his team rearranged the pebbles and other objects in male courts.
"When we reversed the gradient, putting smaller objects further away and larger objects closer to the avenue, the birds put the gradient back in three days," he said.
In the future, he and other researchers hope to see if all of this architectural effort is related to mating success, and if other animals might use forced visual perspective too.
It's possible that many organisms are optical illusion masters. But are their creations art?
"This depends upon the definition of art," Endler said. "Flowers produce things to be looked at and attracted to by pollinators. Is that art? Fiddler crabs produce towers to attract females. Is that art? Spiders spin orb webs to attract prey. Is that art? These could (all) be called art."