Animal Behavior: Size Matters

With apologies to the toucan and parrot, a peacock’s plumage ranks highest on the aviary beauty scale. Yet those colorful contenders might find solace in this: Ms. Peacock may not be as impressed with the display as Mr. Peacock is.

Duke neuroscientist Michael Platt and his colleagues attached eye-tracking equipment to the head of a peahen and used the resulting video to study courting peafowl at an outdoor enclosure. The researchers concluded that a male’s display, so impressive to humans, isn’t what catches a peahen’s eye.

Instead, the ladies devoted considerable attention to the lower part of the peacock’s train, significantly ignoring the top part of the train, his head, and crest. “It’s reasonable to speculate here that what matters is something like size rather than ornamentation,” says Platt. “Size is related to a male’s age, and a male’s age is a pretty good predictor of breeding quality in these birds, so that wouldn’t be a bad strategy in these birds.”