Modified contour feathers on the head are also commonly used in courtship displays. Structurally, the feather is bizarre, with a bare rachis rachis RAY-kissthe stiff central shaft of a feather from which barbs branch that ends in a tight spiral of barbs barbone of the main branches off the central shaft of a feather and barbules barbule barb-YOOLone of the secondary branches off a feather barb arranged only on one side of the rachis to form an eye-catching brilliant medallion. For example, the iridescent spiral from a King Bird-of-Paradise ( Cicinnurus regius) tail functions as an ornament in the male’s courtship display. Some feathers are so highly modified for display that they almost don’t look like feathers at all. Wood Duck by Melissa Groo, King Bird-of-Paradise by Tim Laman They are essential for steering, but only the two most central feathers attach to bone.

Tail feathers, or rectrices rectrices RECT-ri-seestail feathers, are also classified as flight feathers. While secondaries secondaryone of the feathers occupying the inner half of the wing that overlap with other secondaries to form an airfoil that provides lift during flight cannot be controlled as extensively, they provide most of the lift by overlapping to form an efficient airfoil airfoilwinglike structure that produces lift and drag as it moves through the air. They occupy the outer half of the wing, can be controlled and rotated like rigid fingers, and provide most of the bird’s forward thrust. The primaries primaryone of the feathers occupying the outer half of the wing that can be controlled to generate forward thrust during flight are longest of the flight feathers. Unlike other feathers, remiges are anchored to bone with strong ligaments ligamentband of tissue that connects a bone to another bone, piece of cartilage, or feather so they can withstand the demands of flight and be precisely positioned. The primary and secondary wing feathers, or remiges remiges REM-i-jeezthe flight feathers on the wing that are attached to bone rather than only to skin, permit birds to take to the skies. Newly unearthed dinosaur fossils from China and Canada have supported these hypotheses by providing specimens from each stage in the proposed evolutionary history-a clear example of how investigating biological structures across contexts can create scientific breakthroughs. Careful study of this process inspired new hypotheses hypothesisan explanation that is testable through study and experimentation about the evolution of feathers through stages of increasing complexity. For example, the interlocking Velcro-like structure on many bird feathers creates the smooth, flexible, and resilient surface that supports flight and sheds water.Īs feathers grow, they mature into highly branched structures. Understanding feather anatomy at the microscopic level provides insight into how feathers function. From the fluffy down on a swan chick to the brilliant spiral on a King Bird-of-Paradise tail, feathers are remarkable not just in the way they look to the naked eye, but also for their intricate microstructure.

Osprey half wing fan