[Biology Class Notes] on Feather Pdf for EXAM

Feather is known as the component structure of all modern birds’ flight surfaces and outer covering. Feathers apparently evolved from the scales of birds’ reptilian ancestors, being Unique to birds. Several different types of feathers are used for flight, insulation, body contour forming, sensory reception, and show reception.

About Feather

Unlike most mammals’ hair, feathers do not cover the birds’ entire skin surface, but they are arranged in symmetrical tracts (also called pterylae) with the bare skin areas (also called apteria) between. And, the latter may contain the small soft feathers known as down.

Parts of a Feather

Let us discuss the parts of a feather in detail. The typical feather contains a central shaft (called rachis), with the serial paired branches (called barbs) forming a flattened, generally curved surface, called a vane. The barbules, as well as the barbs, have roots, and the barbules of neighbouring barbs are connected by hooks, stiffening the vane. In several birds, either some or all of the feathers lack the hooks or the barbules, and the plumage has a hairlike, loose appearance.

Usage of Feather

Feathers have been used as regalia and for ornamentation in several societies, both highly developed and nonliterate. Hats and other accouterments are featured or have been constructed totally of feathers and, at times, either entire wings or the pairs of wings down to modern times. Many governments have protected the colourful species of birds from preventing the extinction of feathers at the hands of feather hunters. Feathers from domestic fowl slaughtered for meat are given to poultry farmers as a regular by-product and are used for padding, decoration, and insulation.

Structures and Characteristics

Feathers are the most complex integumentary appendages found in vertebrates, and they are formed in tiny follicles that contain keratin proteins in the epidermis or outer skin layer.

The β-keratins in feathers, claws and beaks – and the claws, shells, and scales of reptiles – are composed of protein strands hydrogen-bonded into the β-pleated sheets, then, that are much stronger than -keratins of mammalian horns, hooves, and hair Disulfide bridges twist and crosslink the -keratins of mammalian horns, hooves, and hair into structures. The exact signals that cause the feather to grow on the skin are unclear, but transcription factor cDermo-1 has been discovered to cause the feather to grow on the skin and scales on the leg.

Types of Feathers

Let us discuss the types of feathers in detail. There are two basic types of feathers. Vaned feathers cover the body’s exterior, while down feathers lie under the vaned feathers. The pennaceous feathers, otherwise called vaned feathers. Pennaceous feathers, also called contour feathers, arise from tracts and cover the entire body. The filoplume, a third and rarer type of feather, is hairlike, and they are closely associated with the pennaceous feathers, and these are often entirely hidden by them, at least on the body, head, and trunk of the bird, with one or two filoplumes attached and sprouting from a near similar point of the skin as any pennaceous feather.

Filoplumes are totally absent in ratites. In a few passerines, filoplumes arise exposed beyond that of pennaceous feathers on the neck. The remiges, or the wing’s flight feathers, and rectrices, or tail’s flight feathers, are the essential feathers for flight. The rachis is a typical vaned feather that features the main shaft.

Functions of Feathers

Feathers insulate birds from cold temperatures and water. They could also be plucked to the line, which is the nest and provides insulation to the young and eggs. The individual feathers present in the tail and wings play an important role in controlling the flight.

On the heads of certain animals, there is a crest of feathers. Although those feathers are light, the plumage of a bird weighs either two or three times to that of its skeleton since several bones are hollow and have air sacs. At the same time, the colour patterns serve as camouflage against the predators for birds in their habitats and also serve as camouflage for the predators looking for a meal.

Human Usage of Feathers

Utilitarian Functions

Feathers are both excellent and soft at trapping heat; therefore, sometimes they are used in high-class bedding, especially blankets, mattresses, and pillows. Also, they are used as filling for outdoor bedding and winter clothing, such as sleeping bags and quilted coats. Eiderdown and goose down have a lot of lofts, which means they can extend from a compressed state to catch a lot of insulating, compartmentalized air.

In Religion and Culture

Eagle feathers contain great spiritual and cultural value to the American Indians in the United States and First Nations peoples as religious objects in Canada. In the US, the religious use of hawk and eagle feathers is governed by the eagle feather law, which is a federal law limiting the possession of eagle feathers to enrolled and certified members of federally recognized Native American tribes.

Whereas, in South America, brews that are made from the condors’ feathers are used in traditional medications. In contrast, in India, the Indian peacock feathers have been used in traditional medicine for infertility, coughs, and snakebite.