Avian - Feathers 0.0 / 5 ? OtherAnimal ManagementOtherOther Created by: Becky_BerryCreated on: 08-12-20 20:15 Introduction to Feathers Feathers are a uniquely avian trait it is now well established that feathers also occurred in dinosaurs In the 1990s feathers were described in a series of non-avian coelurosaurs, mostly from the Chinese Liaoning deposits Feathers are what enable birds to fly thought to have evolved as a thermoregulatory device Feathers are lightweight but strong the surface is made up of tightly spaced, overlapping filaments that hook together overlapping feathers form the wings which birds fly 1 of 11 Types of Feather For example Vaned or contour down semiplume filoplume bristle powder down There are two main categories of feathers Plumaceous - downy for insulation Pennaceous - linked, vaned feathers. Wing and contour feathers. 2 of 11 Feather Structure Made of keratin an inert substance that consists of insoluble microscopic filaments embedded in a protein matrix also found in hair, nails, claws and scales of other animals bird keratin is unique and differs from that of modern reptiles a contour feather has a long central shaft and a broad flat vane the hollow base of the shaft (quill) anchors the feathers to the follicle under the surface of the skin the rest of the shaft (rachis) supports the vanes branching of the rachis are barbs each barb has barbules projecting either side that interlock with the barbules of adjacent barbs barbs and barbules form an interlocking, but flexible, surface vane of a typical body feather consists of a hidden downy base (for insulation) and an exposed cohesive outer portion (for streamlining) 3 of 11 Feather Structure: Pennaceous Feathers give birds a streamlined shape, protection from moisture, and the ability to manoeuvre freely in the air 4 of 11 Feather Structure: Plumaceous Feathers the body feathers of most birds include an aftershaft that emerges from the underside of the shaft where the first basal barbs of the vane branch off the aftershaft is almost always downy functions to increase insulation in the ptarmigan winter plumage, the aftershaft is 3/4 as long as the main feather 5 of 11 Other uses for feathers: Make Sounds male club-winged manakins use the feathers as mating calls as part of an elaborate dance when the feathers rub against each other they make a high-pitched sound the feather vibrates at 1500 cycles per second, stridulation male American woodcocks clap their wings fast high in the air which creates twittering sounds have narrow gaps between their feathers which create the sound 6 of 11 Other uses for feathers: Reduce sound Owls 3 feather features comb-like structures where the air first hits the wing, reducing the turbulence and overall noise on the trailing edge, there are wispy fringes which scientists thinks help smooth airflow soft-velvet covering on the top of the wings 7 of 11 Other uses for feathers: Hearing facial discs in owls the feathers reflect sound which help them pinpoint soft noise 8 of 11 Other uses for feathers: Digestive Aid Grebes eat their feathers to slow digestion and stop fish bones etc. damaging their digestive tract feathers can fill up half the gizzard don't swallow stones like other birds the pyloric pouch is where the smaller feather ball filters out sharp bones 9 of 11 Other uses for feathers: Fishing form an umbrella which it then hunts under thought the shade could either reduce glare or draw fish in, or scare away smaller fish and leave medium and large fish 10 of 11 Other uses for feathers: Water transport, snowshoe Water Transport Sand grouse use specialised belly feathers to transport water back to their young a single bird can pick up 40ml when wet the feathers such in water Snowshoes the feathers quadruple the area of their foot which makes it less likely to sink into the snow thought to reduce the sinking by half save energy while travelling some species grow these feathery snowshoes every year Courtship displays birds of paradise 11 of 11
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