National Geographic : 2012 May
SOUTH AMERICA CENTRAL AMERICA 0mi 1,000 0 km 1,000 COLOMBIA ECUADOR Range of club-winged manakin Range of 40 known manakin species (family Pipridae) NG MAPS SOURCE: CORNELL UNIVERSITY MUSEUM OF VERTEBRATES Vertebrates---who broke the code of the male club-winged manakin, a standout among manakins. It is the only spe- cies that uses its feathers to generate a tick, tick, ting in the hope of making a female swoon. Scientists knew the wings were the source of the sound but didn't know exactly how the process worked. To crack the conundrum, Bostwick recorded the bird's movements on a video camera operating at a thousand frames per sec- ond, more than times as fast as a standard camcorder. Viewing the video a few frames at a time led to a eureka moment: e bird was knocking its wings together times a second. Examining the bird's secondary feathers in the lab, Bostwick saw on each wing a specialized feather with seven separate ridges. e h feather rubs against the ridged feather in a plectrum-like action---in music termi- nology, that's a plucking device, like a guitar pick---to reach a frequency of an astonishing , cycles per second (seven ridges, each plucked twice = , multiplied by = ,). e result is a violin-like tone, somewhere between an F sharp and a G, more than two octaves above middle C. e world has nearly , species of avifauna, but no other creates sound this way---by scraping body parts together (although crickets do something similar). Bone density appears to be critical. In a paper that will be published later this year, Bostwick and her colleagues describe how they conducted micro-CT scans of manakin wings and discovered that the wing bones are solid. Most birds have hollow bones, which lighten the load when alo . e manakin's bulky bones, Bostwick says, likely have evolved in order to support the knocking action of the large feathers. But how, she wants to know, does this three- and-a-half-inch bird haul around the extra weight when it ies? And how does it manage "the incredible energy cost and physics involved in using that wing"? ese are the next manakin mysteries to solve. j Stay-at-home birds The club-winged manakin's range stretches through the cloud forests of southwest Colombia and north- west Ecuador. The bird is a home- body, living in colonies that occupy the same patches of land year-round. Dan Koeppel is the author of To See Every Bird on Earth. Tim Laman explored the lairs of bowerbirds for our July 2010 issue. THIS ARTICLE IS BASED UPON WORK SUPPORTED BY THE NATIONAL SCIENCE FOUNDATION UNDER GRANT NO. 0547709. ANY OPINIONS, FINDINGS, AND CONCLUSIONS OR RECOMMENDATIONS EXPRESSED IN THIS ARTICLE DO NOT NECESSARILY REFLECT THE VIEWS OF THE NATIONAL SCIENCE FOUNDATION.