Primary Feather

Primary Feathers
The long, fingertip feathers are a bird's primaries. Alan Vernon

Definition:

(noun) One of the main flight feathers along the outer edge of a bird's wingtip.

Pronunciation:

PREYE-mair-eee FEH-therr

About Primary Feathers

Primary feathers are the "fingertip" feathers, the longest on a bird's wing. In flight, they are responsible for thrust to propel the bird forward, and each feather can be rotated individually to control flight directions and to adjust lift and air resistance.

For example, if the feathers are lifted and splayed, the bird's flight will slow and the altitude will drop, a posture many birds use when landing. If the primary feathers are held tightly together in a narrow point, the bird's flight will be faster and more precise, such as a stoop hunting dive by birds of prey.

When primary feathers are replaced through regular molting, they are generally shed in pairs, with one feather lost at a time from each wing. The feathers are lost in the same position from each wingtip, which helps the bird stay balanced in flight. If multiple primaries are lost through an injury, flight can be much more difficult.

Identifying Birds by Their Primaries

Primary feathers can be used for bird identification in several ways.

  • Number: The number of primary feathers a bird has depends on the species and how specialized the feathers are – most birds have 9-16 primaries. This can be useful for ornithologists or bird banders to properly identify very similar species or subspecies, but is less effective for birders in the field since the bird must be held in the hand to properly count feathers.
     
  • Color: The color of primaries may contrast with other parts of the wing, creating a bar or patch effect on the plumage. This color can be a key field mark for identification, particularly for identifying birds in flight when their primary feathers are easily visible. On some birds, such as many owls, the individual primaries may be striped, spotted or barred.
     
  • Shape: The overall shape of primary feathers can be useful for identification, especially if the feathers are found after they are shed. The total length measurement can be a clue to the bird species, and whether the tip is rounded, tapered or sharply pointed can also be helpful.
     
  • Flight Position: How the bird holds its primary feathers in relaxed, gliding flight can be a good identification clue. Some birds, such as turkey vultures, have a much wider natural splay to their primaries, while hawks keep these feathers more closely together.
     
  • Folded Projection: When a bird is perched, the primary feathers will project past other parts of the body, and the length of that projection can help identify bird species. Primaries may be compared to the position of the secondary feathers, tail tip or other markings on the body for identification purposes.

Primaries in Culture

In cultures where certain birds are honored or otherwise spiritually significant, primary feathers may hold sacred value because of their size and distinction. Many Native American cultures use the primary feathers of eagles, hawks and other raptors for ceremonial dress or adornments. In some African cultures or similar pagan-like beliefs, primary feathers may be used as part of rituals for potions or spell-casting.

Also Known As:

Primary, Primary Quill, Primaries (plural)

Photo – Barn Swallow Wing Showing Primaries © Alan Vernon