What catches an Indian peahen’s eye? Most of the time, it’s not the peacock‘s showy tail, a new study says.
Scientists who used eye-tracking cameras to follow peahens’ gazes found that the female birds spend only 20 to 30 percent of their time looking at a displaying male, and the rest of the time looking around for food or predators.A peahen outfitted with eye-tracking technology. Photograph by Jessica L. Yorzinski
During peacocks’ dazzling courtship displays, males show off an extravagant train of iridescent blue-green feathers to attract the attention, and hopefully affection, of peahens. (Watch a video of an Indian peacock showing off for a female.)
But scientists weren’t sure what it was about the showy tails that attracted females. So they outfitted peahens with high-tech caps and backpacks to get a bird’s-eye view of the action.
Through the Bird’s Eyes
Jessica Yorzinski, who led the research while a graduate student at the University of California, Davis, decided to see what parts of the male’s display attracted the females’ attention.
Along with colleagues from Duke University, Yorzinski devised a system to track where captive peahens directed their gaze, according to the study, published in the August issue of The Journal of Experimental Biology.
The peahen wore a plastic cap holding two cameras and an infrared LED and a backpack with batteries and a wireless signal to collect and broadcast the video to a nearby computer.
One camera filmed the field of view in front of the peahen while the other tracked the movement of her pupil, revealing where she looked.
“This is the first study to ask the females what they’re really attending to,” Yorzinski said in a press release.
The system underwent extensive tinkering to get it just right. Yorzinski and her colleagues tested the equipment by tossing food near the birds and placing a taxidermied raccoon, serving as a potential predator, in their enclosure. Eventually, the researchers were satisfied that the video showed the world through the peahens’ eyes.
What Does She See in Him?
Surprisingly, when peahens did look at the males, they didn’t pay much attention to the male’s head or the top of his tail, which looks a big, outstretched fan. Instead, they directed their gaze toward the bottom, and wider, part of the fan.
Females might only look at the top of a male’s fan when they’re trying to locate him at a distance: In the birds’ natural environment in South Asia, dense vegetation obscures most of the male’s display from far away. When a female then gets close enough for a better look, the male will dance and rattle his feathers to keep her attention. (See National Geographic’s bird pictures.)
In addition, Yorzinski and colleagues speculate that peahens are judging the size and symmetry of the lower part of the male’s display. The bottom of the peacock’s fan, called a train, continues to grow larger until he is about five years old—thus, a sizable train would indicate a successful male who would pass on better genes.
So while the male’s iridescent fan tail might look impressive to our eyes, it seems for choosy peahens that beauty is in the eye of the beholder.