Female avoid harassment by looking as flashy as males 26 August 2021

was clear something was at play."

Male white-necked Jacobin hummingbirds are known to have bright and flashy colors, with iridescent blue heads, bright white tails, and white bellies. Female Jacobins, on the other hand, tend to be drabber in comparison, with a muted green, gray, or black colors that allow them to blend into their environment. Falk and his team, however, found that around 20% of adult females have showy colors like males.

As juveniles, all females have the showy colors, but this 20% of females doesn't change to the muted color as they age. It is not clear whether this A male-like female white-necked Jacobin phenomenon is genetic, by the choice of the being released after capture and tagging. Credit: Irene hummingbird, or due to environmental factors. Mendez Cruz However, the researchers found that it is probably the result of the female hummingbirds trying to evade harassment, including detrimental aggression during mating or feeding. Much like in human society, female hummingbirds have taken it into their own hands to avoid "Hummingbirds are such beloved by many harassment. By watching white-necked Jacobin people, but there are still mysteries that we haven't hummingbirds in Panama, researchers discovered noticed or studied," says Falk. "It's cool that you that over a quarter of females have the same don't have to go to an obscure unknown to find brightly colored ornamentation as males, which interesting and revealing results. You can just look helps them avoid aggressive male behaviors at a bird that everyone loves to watch in the first during feeding, such as pecking and body place." slamming. This paper appears August 26 in the journal Current Biology.

"One of the 'aha moments' of this study was when I realized that all of the juvenile females had showy colors," says first author Jay Falk, who is now a postdoc at the University of Washington but led the research as a part of the Cornell Lab of Ornithology and Smithsonian Tropical Research Institute. "For that's really unusual because you usually find that when the males and females are different the juveniles usually look like the adult females, not the adult males, and that's true almost across the board for birds. It was unusual to find

one where the juveniles looked like the males. So it

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The left and center images show adult female and adult male plumages, respectively. Right image shows juvenile plumage. Credit: Artwork by Jillian Ditner, Cornell Lab of Ornithology.

To learn why some female hummingbirds kept their showy colors, the researchers set up a scenario with stuffed hummingbirds on feeders and watched as real hummingbirds interacted with them. They found that hummingbirds harassed mainly the muted colored female hummingbirds, which is in favor of the hypothesis that the showy colors are caused by social selection. Furthermore, most females had showy colors during their juvenile period and not during their reproductive period. This means that the only time they had showy colors is precisely during the period when they're not looking for mates. In combination with other results from the study, this indicates that it is not sexual selection causing the phenomenon.

In the future studies, Falk and his team hope to use the results of the variation between female white- necked Jacobins to understand how the variation between males and females in other may evolve.

More information: Current Biology, Falk et al.: "Male-like ornamentation in female hummingbirds results from social harassment rather than sexual selection" www.cell.com/current-biology/f … 0960-9822(21)01033-2 , DOI: 10.1016/j.cub.2021.07.043

Provided by Cell Press APA citation: Female hummingbirds avoid harassment by looking as flashy as males (2021, August 26) retrieved 1 October 2021 from https://phys.org/news/2021-08-female-hummingbirds-flashy-males.html

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