Female hummingbirds that look male avoid harassment and have more time to eat

Researchers have found that, for females of a hummingbird species, looking more like males has an important advantage: being left alone.

In young white-necked Jacobins, a relatively large hummingbird that ranges from southern Mexico to parts of South America, both young males and females have bright blue feathers on their heads. As the birds grow, most females lose their striking colors and develop a duller green and white color. But not all.

According to the study, published in the journal Current Biology this week, about 20% of the adult birds in a Panamanian population maintained the bright blue plumage normally seen in adult males.

To investigate what this might mean, the researchers did a couple of things. They put tracking tags on some birds to monitor their feeding behavior. On a slightly more morbid turn, they also released taxidermy birds to observe the reactions of live birds, CNN reports.

They noticed some things. On the one hand, males had much more sexual interest in black-colored females. But males were also much more aggressive toward these females during feeding time, chasing them, biting them, and even beating them, according to the New York Times. So the brighter colored females, the ones that looked like males, had more time to eat without bothering.

“Our tests found that typical, less colorful females were harassed much more than females with male-like plumage,” Jay Falk, lead researcher at the Cornell Lab of Ornithology, said in a press release. “Because male plumage females experienced fewer aggressions, they were able to feed more often, a clear advantage.”

This is a great thing, as hummingbirds need to eat constantly. Simpler feeding time can make a big difference in your survival.

Falk told the Times that it is not yet clear what the mechanism is that allows some female birds to retain their bright colors in adulthood, but hopes to do more research on them.