Birds and bots: a mating tale

A male bowerbird courts the "fembot" used by University of Maryland researchers.

By Marsha Walton
CNN Sci-Tech

COLLEGE PARK, Maryland (CNN) -- The female bowerbirds of Australia and New Guinea are pretty particular about their mates; they have to combine the hot, sensual moves of a Ricky Martin, with the dependable construction skills of a Bob Vila.

Hot, but not too hot, according to researcher Gail Patricelli of the University of Maryland. A male bowerbird also has to be something of a sensitive, new age guy.

"So the most appealing, successful males are the ones who give really high intensity, aggressive displays without threatening the female. They observe female behaviors and they increase their intensity as the female signals that she's comfortable, without being intense too soon," says Patricelli.

Researchers say bowerbirds are well known in animal behavior and evolutionary circles because of their bizarre mating rituals.

Pick me, pick me!

University of Maryland biologist Gail Patricelli with one of the female bowerbird robots used in the study.

Patricelli and her colleagues used three robotic female birds to better gauge just how males adapt their moves as they court a female. Their work, described in the journal Nature, says the males either enhanced or toned down their displays based on the reactions of the "fembot," (nicknamed Jaime Sommers after the character in "The Bionic Woman.")

"We want to know more about how animals communicate, and we know during these elaborate courtships, the male is basically saying, 'Mate with me.' But he also needs to know how to respond to the female, to interact with her," says Patricelli.

Unlike peacocks, where looks matter most in selecting a mate, female bowerbirds look for more: a sense of symmetry and style in a home.

An unusual trait of these birds is the sometimes elaborate bower, or bachelor pad that's built by the male. It's meticulously constructed with sticks and twigs, then decorated with small objects ranging from colorful leaves to feathers, snail shells, or dead spiders.

VIDEO CNN's Ann Kellan reports on how scientists manipulated a robotic bird to learn more about mating habits of the bowerbird. Play video (QuickTime, Real or Windows Media)

Like wandering through a subdivision, the females fly around an area of a square kilometer or so and stop at the most attractive bowers. That's the cue for the males to start their song and dance.

"He struts and dances in front of the female, puffs up his feathers to make himself look larger, and runs back and forth flipping his wings and making a loud buzzing sound," says Patricelli.

There are two types of losers in the bowerbird world during mating season, which lasts from late October through December.

"There are the males that never give intense displays; they just kind of ... don't have it," says Patricelli. "Then there are the males that are too intense too soon before the female is ready, so those are the males that don't know how to use it."

When you've got it, you've got it

During three seasons of field research in Australia, Patricelli says one male really stood out.

Bower bachelor pad: females are attracted to colorful, symmetric bowers, or mating areas built by males.

"He was extremely sexy, during the seven week mating season he would mate with 25 or 26 females. He basically did everything right, he had a very nice bower, very nicely built with lots of decorations, and he was very good at the courtship dance and responding to the females."

And females seem to know a good catch when they find one.

When they discover a real gem of a male, they tend to go back to his bower year after year, say researchers.

But there's a tradeoff for the female, who get to call all the shots when it comes to picking a mate -- she also assumes 100 percent of parenting duties when the baby bowerbirds come along.