Female hummingbirds dressed in male plumage get harassed less
"They avoid the bullies by looking like them."
Hummingbirds are famous for fast flights, bright colors and constantly needing food to support their high-energy activities.
White-necked jacobin hummingbird males sport eye-catching blue, green and white feathers, while most adult females have a more muted green look. But some of the females actually look like the males, and it turns out there are distinct advantages to that fashion statement.
A team led by Cornell University researchers studied white-necked jacobin hummingbirds in Panama and found that almost 30% of the adult females look like the males. The hummingbirds are a bit unusual in that the juveniles all sport male-like plumage. The adult males retain that appearance, while most of the adult females grow into the muted colors.
"Our tests found that the typical less colorful females were harassed much more than females with male-like plumage," said ornithologist Jay Falk, now with the University of Washington, in a Cornell statement on Thursday. "Because the male-plumaged females experienced less aggression, they were able to feed more often -- a clear advantage."
From left to right are the plumages of white-necked Jacobin hummingbird adult females, adult males and juveniles.
Falk is the lead author of a paper on the hummingbirds published in the journal Current Biology this week. The researchers tagged birds to monitor their meals at a series of feeders. The study found that the male-plumaged females spent about 35% longer at the feeders than typical females.
The researchers also monitored hummingbird behavior toward taxidermy versions of the birds, and found that the ones with female plumage received more aggressive and sexual attention.
As Cornell put it, "female white-necked jacobins retain the male-like plumage of their youth for social reasons. They avoid the bullies by looking like them."
The hummingbirds in the study aren't alone. There are other hummingbird species with some females dressed in male plumage. The ability to minimize social harassment and get more sustenance in a competitive environment is plenty of reason to rock the menswear-inspired look.