Biologists puzzle over birds' ensemble vocalizations
As the morning mists rose on the slopes of Ecuador's Pasochoa volcano, the burbling of plain-tailed wrens came through the bamboo thickets. Two researchers started their standard procedure of catching wrens, banding them, and letting them go. Soon, however, they were startled when a small cluster of wrens settled into a bush and began singing together. It turned out to be "one of the most complex singing performances yet described in a nonhuman animal," says Nigel Mann.