Researchers in the Central American rainforest have made a remarkable discovery: Some of the hummingbird females disguise themselves as males, leaving them more alone by the opposite sex.
Whereas in the animal kingdom it is usually the males who are dressed colorfully and flamboyantly, the situation appears to be different for hummingbirds, the biologists discovered. They caught 436 white-necked hummingbirds in the rainforest of Panama. About 20 percent of the adult female birds did not have gray plumage, but were colorful – exactly like their male counterparts.
The researchers propose two scenarios. Option one is that the females grow colorful feathers to attract males of their own kind. In the second scenario, the opposite happens. The bright colors keep the males at a distance, so that females are less bothered by unwanted behavior. This gives them more time to look for food and protect their food supply, the biologists suggest.
“The bright coloring is associated with aggression,” University of Washington researcher Jay Falk told National Geographic. “Looking like a male seems to deter bullies.” The research was published today in the journal Current Biology.
Evidence
The researchers made another remarkable finding: All the young animals had brightly colored feathers, which is not common in birds. Some of the females only got a grayer plumage at a later age.
According to the biologists, that finding supports the theory that the brightly colored disguise protects females from whistling. After all, the young (brightly colored) birds cannot reproduce yet and it is of no use to be found attractive. But if they know how to scare off congeners, it does help them survive.
The biologists saw the decisive evidence in the ultimate preference of the males. They paid more attention to grey-colored females.
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