Summary
In October 2022 a bird with the code name B6 set a new world record that few people outside the field of ornithology noticed. Over the course of 11 days, B6, a young Bar-tailed Godwit, flew from its hatching ground in Alaska to its wintering ground in Tasmania. Feathers, such as those of the Lesser Flamingo shown here, are products of hundreds of millions of years of evolution. The discovery of feathered nonbird dinosaurs sent researchers scrambling to understand the origin and evolution of feathers. Some species were clearly not fliers, given the small size of their “wings’ relative to their large bodies. But other pennaraptorans, such as the Microraptor, are trickier to interpret. Many of the arguments about whether this creature could fly have centered on something called vane asymmetry. powered flight probably evolved multiple times in dinosaurs, says Michael Pittman. Only in birds did flight feathers attain the degree of shape-shifting we see today. The wing of the Greater Prairie-Chicken, a type of grouse, has a slotted tip that helps the bird burst into flight when startled. Researchers have begun to piece together the intricate process by which feathers develop. Scientists have shown a recent surge of interest in another category of feathers: display feathers, the showy feathers that help to attract mates. These feathers begin as a tube that essentially unzips along its length, forming the two vanes. The microstructure of display feathers, especially tail streamers, may be more finely tuned than previously thought. Feather structure provides a balance of stiffness, weight and shape. The feathers must hold their shape well enough, even at extreme lengths, to be effective signals. The extremely stiff feathers of hummingbirds such as Anna’s Hummingbird help to support their distinctive, hovering flight. Even ultrasensitive microphones, if properly calibrated, can just barely pick up sounds from a flying owl... sometimes. Owls have a “velvety” surface that silences them when they move against one another. The feathers on the leading edge of an owl’s wing have a set of comblike structures. The flightless penguins have adapted to life in the water and on land. They have converted their entire body covering into a densely packed mosaic of tiny feathers. Silencing fringes of owl feathers have inspired ventilation-quieting systems. The surface texture and boundary-layer-control principles of penguin feathers have made their way into robotics, mostly in prototypes.
