External Anatomy of a Bird

Parts of a Song Bird

Head Feathers

Detailed topography of head feather groups, showing complexity of head feathering on a typical passerine. Top: A schematic diagram of the groups. Bottom: The actual markings on White-throated Sparrow.

Body Feathers

Passerine in alert, sleeked posture. In this pose, with the wings held out from the body, the usually concealed lesser coverts and marginal coverts are easily seen.

Wing Feathers

Top: Right wing of a passerine, closed but held loosely. Note how the feathers stack up, with the innermost tertial on top and the outermost primary on the bottom. With the wing folded against the body, only the outer edges of the remiges are visible. Secondaries and primaries are numbered from center of wing (same order in which most species molt).

Passerine in flight, from above. Note that outer webs of flight feathers are visible.

Passerine in flight, from below. Note that inner webs of flight feathers are visible.

Parts of a Shorebird

Top: Small shorebird, relaxed. This typical shorebird differs significantly from passerines in wing structure and in its two distinguishable groups of scapulars, which are much more prominent than the scapulars on passerines. The scapulars hang loosely when relaxed, covering most of the wing. (They are often pulled up when active, exposing the wing coverts.) The secondaries and primaries are nearly or entirely concealed when the wings are folded. Note the many rows of lesser coverts (bottom illustration). The pale V on the back of many shorebirds is formed by pale edges on the mantle and upper scapular feather groups.

Small shorebird, active. Note how changes in posture affect shape of nape, mantle, scapulars, throat, and breast.

Parts of a Duck

Duck, swimming. Note that waterbirds such as ducks and shorebirds are more or less uniformly covered with feathers to create seamless waterproofing. It may be difficult to distinguish the feather groups on any part of a bird that is normally in contact with water.

Parts of a Gull

Large gull, standing. All feather groups are essentially the same as on a shorebird.

Gull in flight, showing feathers typical of most long-winged species. Left: From below. Right: From above. The pale wingstripe seen on many shorebirds is formed by pale bases of secondaries and/or primaries (often combined with white tips on greater coverts). Windows are translucent patches on flight feathers, visible on a flying bird, where lightly pigmented areas allow light to pass through. A carpal-bar is a contrastingly colored band on the upperwing, extending along a diagonal line from tertials to carpal joint, or "wrist" (not always the entire distance). A dark carpal bar forms part of the M pattern seen on many species. Interestingly, this bar crosses all the rows of wing coverts and does not follow the contours of any single feather-tract.

Head of large gull, showing bare parts that are important in gull identification.