July 25, 2013
What Peahens Want
Brett Smith for redOrbit.com - Your Universe Online
Finding out what women want is a question that science may never answer. However, a team of biologists from the University of California, Davis and Duke University has gained new insight into what a typical peahen may be looking for in her mate.Peacocks are renowned for their colorful trains, which are grown during the mating season and used to attract females. But what about the train catches a female eye?
To see how these colorful displays affect a peahen, the research team decided to track the eye movements of several females in the presence of their male suitors. First, they trained twelve peahens to wear tracking equipment that included one camera for recording the scene in front of the bird and another camera for tracking eye movement.
According to the scientists' report in the Journal of Experimental Biology, the experimental setup was tested by tossing an appetizing mealworm or a taxidermied raccoon 'predator' into the peahens' enclosures. The tracking device was effectively able to watch where the birds directed their gaze, researchers said.
Next, each peahen was introduced to two males. As the males prominently displayed their trains, the females did their part in the courtship ritual - inspecting the peacocks from both the front and back. Like females of other species, the peahens only spent a fraction of their time - around 21 to 27 percent - being engaged in what the males were actually doing. Their attention was more often focused on their environment, potentially looking for predators or food.
Some males were able to draw additional attention from the peahens by shaking their tail feathers, but researchers said they were surprised to find where the females fixed the majority of their attention.
"The female spent most of her time gazing at the lower portion of the train, rather than at the crescent above the head, going back and forth along the bottom of the train," said Jessica Yorzinski, who worked on the study as a PhD student at Duke. "Almost all of her gaze was directed below the head and very little on the upper part of the train."
Yorzinski said the peahens were observed scanning the bottom of the trains from side to side, possibly interested in its width.
"I wondered why females primarily looked at the lower portion of a peacock's train," Yorzinski said. "It became clearer to me after travelling to India to observe the birds in their native habitat. I saw that only the upper train of a peacock was visible at a distance because of the high vegetation."
To test her theory that the upper part of the train is only meant to be seen from afar, the former Duke researcher fashioned a train and blocked the lower portion behind a barrier. When peahens were shown these fake trains, they were observed scanning the upper train more than when the lower train was also visible.
The research team also found that peahens tended to approach a distant train in to get a better view. This led the team to conclude that the upper train may initially lure a peahen in, but bottom feathers appear to be essential in 'sealing the deal.' The scientists said they still aren't sure why this part of the train is so captivating for the typical peahen.