Brightly colored feathers may be the key to these hummingbird females avoiding physical fights with others of their species.
Female hummingbirds usually have feathers off, but researchers found that about 20 percent of white-necked Jacobin females have bright feathers, like their male counterparts, which saves them from being socially harassed, according to a study published Thursday in Current Biology.
Young birds often begin with female feather coloration, but in the case of this species of hummingbird they are born male-looking, said study author Jay Falk, who worked as a doctoral student at the Ornithology Laboratory. of Cornell and the Smithsonian Tropical Research Institute during this study. He is currently a postdoctoral fellow at the University of Washington in Seattle.
Seeing all the juvenile birds look male “is pretty unusual in birds, and it was so unexpected that it actually took me a few years to see it in the data,” Falk said.
As the hummingbirds he studied grew, only 80% of the females transformed into more serious colors, leaving the rest of the females with a male color.
Researchers placed hummingbird taxidermy mountains throughout Gamboa, Panama, and observed how other hummingbirds interacted with them.
Male-colored females faced less social harassment from other male and female hummingbirds compared to their quieter counterparts, Falk said.
He noted that hummingbirds often chased or stung each other.
Scientists don’t know for sure how or why some females maintain their male plumage, but the adaptation may be food-related, said Kimberly Rosvall, an associate professor of biology at Indiana University in Bloomington. participate in the study.
“The data suggest that these more aggressive females with male-like plumage are better at defending a key food resource,” she said. “They do more persecution and are less persecuted.”
Easily available foods are a critical resource for hummingbirds because they have a high metabolism, which means they need to eat a lot, said James Dale, a professor of zoology at Massey University in Palmerston North, New Zealand, who did not participate in the ‘study. .
Colored plumage social protections
Females can avoid fighting brightly colored birds because they could be dangerous, Falk said.
“She may recognize that coarse females are less dangerous, which leads her to attack coarse females,” she added.
Although rare in the experiment, Falk said males can annoy females by courting them.
Male hummingbirds do not help raise their offspring, Dale said, and are able to have more offspring if they can convince more females to mate with them.
In the experiment, males preferred to mate with hummingbird females that had dark, female coloration rather than male-colored females, Falk said. However, the males also courted and mated with the male-like female mounts, he added.
In the future, Falk said he is interested in investigating why only some of the female hummingbirds look male as adults.
Research has shown how beneficial male-colored feathers are for female hummingbirds, Dale said, but most females do not maintain their male-colored plumage.
“Despite the costs of harassment, there must be some benefits for females to transform into a typical female coloration,” Dale added.