feather (redirected from feathered own nest)

Feather, river, 80 mi (129 km) long, rising in three forks in the Sierra Nevada, uniting N of Oroville, Calif., and flowing S into the Sacramento River, N of Sacramento, Calif. The Feather River basin was a rich source of gold in the mid-1800s. The Feather River project (1957–68), which includes Oroville Dam, furnishes central and S California with water and provides flood control, recreation, and hydroelectricity in the river basin.

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feather

Structures of a typical contour feather. The feather's central shaft (rachis) has a series of …

(credit: © Merriam-Webster Inc.)

Component structure of the outer covering and flight surfaces of all modern birds. Unique to birds, feathers apparently evolved from the scales of birds' reptilian ancestors. Like hair, feathers are made of keratin, a fibrous protein. They are variously specialized for insulation, flight, formation of body contours, display, and sensory reception. Contour feathers form most of the surface of the bird, streamlining it for flight and often waterproofing it. The basal portion may be downy and thus act as insulation. The major contour feathers of the wing (remiges) and tail (rectrices) function in flight. Contour feathers grow in tracts (pterylae) separated by bare areas (apteria) and develop from follicles in the skin. Down feathers have loose-webbed barbs, all rising from the tip of a very short shaft. Their function is insulation, and they may be found in both pterylae and apteria in adult birds. They also constitute the first feather coat of most young birds. Filoplumes are hairlike feathers with a few soft barbs near the tip. They are associated with contour feathers and may be sensory or decorative in function. Bristlelike, vaneless feathers occur around the mouth, eyes, and nostrils of birds. Some bristles function as eyelashes on ground-dwelling birds; bristles over the nostrils may serve as filters.

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feather

1. any of the flat light waterproof epidermal structures forming the plumage of birds, each consisting of a hollow shaft having a vane of barbs on either side. They are essential for flight and help maintain body temperature

2. Archery

a. a bird's feather or artificial substitute fitted to an arrow to direct its flight

b. the feathered end of an arrow, opposite the head

3. Nautical the wake created on the surface of the water by the raised periscope of a submarine

4. Rowing the position of an oar turned parallel to the water between strokes

5. a step in ballroom dancing in which a couple maintain the conventional hold but dance side by side

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Feather

A specialized keratinous outgrowth of the skin, which is a unique characteristic of birds. Feathers are highly complex structures that provide insulation, protection against mechanical damage, and protective coloration, and also function significantly in behavior. One special functional role is in flight, where feathers provide propulsive surfaces and a body surface aerodynamically suitable for flight. Feathers are used in maintenance of balance and occasionally in the capture of prey and various specialized displays.

Types of feathers

A representative definitive feather contains a single long central axis which supports a row of small branchlike structures along each side (barbs). Barbs form the vane, or web, of the feather. Individual barbs branch off at variable angles and point toward the outer tip of the feather. The barbules are small branches from the barbs. They lie in the same plane as the barbs and arise in rows from their anterior and posterior surfaces. The anterior barbules have a flattened base and a series of small hooklike projections which attach to the proximal ridge of the posterior barbules of the next barb, forming an interlocking structure characterized by its great strength and light weight. All feather types consist basically of these structural elements.

Most of the superficial feathers are contour feathers (pennae). These include the large flight feathers (remiges) of the wing and the long tail feathers (rectrices). Other common feather types include the down feathers (plumulae), intermediate types (semiplumes), and filoplumes (see illustration).

Feathers normally undergo attrition because of the physical abuse attendant to the normal activity of birds. In most species, feathers are replaced completely at least annually, and many of the feathers are replaced more frequently. The sequence of feather molt is surprisingly orderly. Penguins, which shed large patches of feathers in an irregular pattern, are an exception. In most species the power of flight is retained during molt. The molt, that is, the normal shedding of feathers and their replacement by a new generation of feathers, is a single growth process which is actively concerned only with the production of the new generation of feathers. The old feathers are pushed out of the follicles passively.

A major physiological role of feathers is to provide insulation. This is accomplished by regulating the configuration of feather and skin in such a way that differing amounts of air are trapped in the dead space so formed. A second mechanism for control of heat dissipation is the balance of the exposure of feathered and unfeathered body parts.

Feathers act as a protective boundary in their role of providing waterproofing. Water repellency is a structural feature of feathers and is the result of precise geometric relationships between the diameter and spacing of barbs and barbules. Preening appears to be more important in the maintenance of this structure than it is for the application of oils or any other natural product, as was once thought.

A third function of the surface configuration and overall pattern of feathers is in the area of behavioral adaptations. These may be of two types. First is concealment, when the bird is cryptically marked to match its background and escape detection. The second type consists of various types of advertisement. See Protective coloration