"Natural selection favors males that are responsive to females and know how to communicate well," said Patricelli. Males that are sensitive to females' signals are more likely to mate with several females, she added.
The results are described in January 17 issue of the journal Nature.
Elaborate Courtship
The male bowerbirds courted the robotic female much as they would a real bird. "At the end of the display, some males—mystified by the lack of further interest—would simply jump on the crouching female and try to mate," said Patricelli.
Male satin bowerbirds become sexually mature at seven years old, when they acquire their trademark black plumage with an iridescent purple-blue sheen. When younger, their plumage resembles that of females, with a combination of green, gray, and brown feathers.
Often these young males are mistaken for females by sexually mature males and courted. "Young males seems to learn courtship rituals by role-playing the other side," said Patricelli.
To further impress females, the males elaborately decorate their bowers with bright blue objects: pen caps, parrot feathers, toothbrushes, baby pacifiers. "Males that have many blue decorations symmetrically arranged on their bowers are more successful breeders," said Patricelli.
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