Mute Swan (also applies to other white swans such as Trumpeter or Tundra Swan)

A magnificent large white waterfowl known for its S-shaped neck and orange bill. This feather is a soft body contour, designed to keep the bird dry and warm while floating in cold water. Adult birds are entirely white, while juveniles (cygnets) are often greyish-brown.

Pure white (leucistic coloration typical of adult swans). There is no banding or iridescence. The white is structural, reflecting all visible light wavelengths.

The distal tip shows a small pennaceous (interlocked) section, while the majority of the feather is plumulaceous (downy and loose). This structure is designed for maximum thermal insulation and loft.

Extremely soft, silky, and lightweight. The surface has a natural water-repellent quality (preen oil) characteristic of aquatic birds.

Pure white color, large size for a downy feather, and a high ratio of plumulaceous (fluffy) to pennaceous (stiff) barbs.

Alkaline or freshwater lakes, ponds, slow-moving rivers, and coastal lagoons. Inhabits both wild wetlands and urban park ponds.

Native to Eurosiberia and Central Asia; widely introduced and naturalized in North America, Australasia, and Southern Africa. Commonly found in temperate climates.

Large herbivores that influence aquatic vegetation growth. In areas where they are introduced, they can be aggressive toward native waterfowl.

Great Egret (thinner rachis, more delicate), Domestic Goose (smaller, stiffer), or American White Pelican (different texture).

Swans have upwards of 25,000 feathers on their bodies, the majority of which are small insulating feathers like this one. They are one of the heaviest flying birds in the world.

Fair to Good. There is some minor clumping of the barbs and small red fibers (possibly carpet or cloth lint) caught in the downy structure, suggesting it was found indoors or near human textiles.

I don’t know