Some male-looking female hummingbirds face less social harassment

(CNN) – Some female hummingbirds are dressed to the nines, but interestingly, they interact less with others.

Brightly colored feathers may be the key to these female hummingbirds avoiding physical fights with other members of their species.

Female hummingbirds tend to have dull feathers, but researchers found that about 20% of female white-necked Jacobins have bright feathers, like their male counterparts, saving them from social harassment, according to a study published Thursday in Current Biology.

Young birds are often the color of the feathers of females, but in the case of this species of hummingbird, they are born similar to males, said study author Jay Falk, who worked as a doctoral student at the Laboratory of Ornithology. Cornell and the Smithsonian Tropical Research Institute during this study. He is currently a postdoctoral fellow at the University of Washington in Seattle.

Seeing that all the young birds look like males “is quite unusual among birds, and it was so unexpected that it actually took me a few years to see it in the data,” Falk said.

When the hummingbirds he studied grew up, only 80% of the females took on duller colors. The rest remained with the color of the males.

The researchers placed taxidermy mounts of the hummingbirds in Gamboa, Panama, and observed how the other hummingbirds interacted with them.

Male-colored females faced less social harassment from other male and female hummingbirds compared to their duller counterparts, Falk said.

Hummingbirds often chase or peck each other, he noted.

Scientists are not sure how or why some females maintain their male plumage, but the adaptation may be related to food, said Kimberly Rosvall, associate professor of biology at Indiana University in Bloomington, who was not involved in the study. study.

“The data suggest that these more aggressive females with male-like plumage are better at defending a key food resource,” he said. “They persecute more and are less persecuted,” he explained.

Foods that are readily available are a key resource for hummingbirds because they have a high metabolism, meaning they need to eat a lot, said James Dale, a professor of zoology at Massey University in Palmerston North, New Zealand, who was also not involved in the study.

Hummingbirds protected by their colorful plumage

Females might try to avoid fighting the brightly colored birds because they could be dangerous, Falk said.

“She may recognize that dull-colored females are less dangerous, which would lead her to attack dull-colored females,” he added.

While it was rare in the experiment, Falk said that males could tease females to woo them.

Male hummingbirds don’t help raise their offspring, Dale said, and they can have more young if they can convince more females to mate with them.

In the experiment, males preferred to mate with female hummingbirds that were dull in color rather than females with typically male color, Falk said. However, the males also courted and mated with the female mounts most prized to the males, he added.

Falk said that in the future he is interested in investigating why only some of the female hummingbirds resemble males when they are adults.

Research has shown how beneficial it is for female hummingbirds to have feathers the color of males, Dale said, but most females do not retain those plumage.

“Despite the costs of harassment, there must be some benefits to females shedding to the typical female coloration,” Dale added.