Golden Hour

Guianan cock-of-the-rock (Rupicola rupicola), two males fighting during lek, Guianan Shield, Suriname

Two opponents face off in the forest, resplendent splashes of orange in a sea of green. The battle between these male Guianan cocks-of-the-rock (Rupicola rupicola)—a raucous display of beak clicks, squawks, and feather puffing—is more neighborhood spat than violent clash. Which is not to say it’s unimportant. At issue in this and countless other territorial disputes that will boil over in this patch of tropical forest throughout the breeding season is attaining—and holding onto—one’s rightful place in the spotlight.

Every January, male cocks-of-the-rock emerge from their normally solitary lives in the forest and gather in small groups at display areas, called leks. Each bird meticulously clears a patch of ground on the forest floor and guards this “court” for the very important performances to come. When a female arrives at the lek, the males drop from their guard perches to the courts below and begin to dance. They hop; they pirouette; they flash their golden plumes and crests, all in an effort to attract the female’s attention.

While it would be impossible for a female to overlook this dazzling competitive display, selecting a single male from among a dozen or more similarly dressed suitors is another matter. Scientist can’t be certain exactly which factors influence female mate choice in cocks-of-the-rock, but they do have some ideas. A study published in Science in 1985 clearly showed that success breeds success. On an average lek, a single male was involved in 30 percent of all matings, while two-thirds of his competitors never bred. Location, too, seems to play an important role in mate selection. Studies have found that males with courts located near the center of the lek are significantly more successful in attracting females.

But the most important factor of all appears to be access to direct sunlight, especially the unfiltered orange and red wavelengths that really make cock-of-the-rock plumage pop. A 1996 study found that males not only defended courts that garnered the best sunlight, they also timed their displays accordingly, dancing only when the spotlight shone most brightly—and with the most golden hues—on their stage. This strategy minimizes the birds’ exposure to predators when display conditions are less than ideal. It also gives their act the best chance of being noticed and appreciated by potential mates, proving yet again the power of flattering lighting during courtship rituals.