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This glossary provides brief definitions of some of the specialized terms used in Piranga. Several of them pertain to parts of the wing, as illustrated below.

Alternate plumage - a distinct plumage of some species corresponding to what is commonly referred to as “breeding plumage”, and arising from prealternate molts

Alula - short feathers (often three) at the leading edge of the wing, above the outer primary coverts.

Basic plumage - the default plumage of all mature birds, arising from prebasic molts; present year-round in some species, and equivalent to the “non-breeding plumage” in species that also have alternate plumage

Complete molt - a molt in which all feathers are replaced

Contributed image - an image that has been uploaded to Piranga but has not been selected by editors as a reference or supplemental image

Definitive - plumage that is the same from year to year, generally equivalent to “adult”

Eccentric molt - a sequence of feather replacement that deviates from the standard; most often, it features replacement of outer primaries and inner secondaries, with a retained block of feathers in between

Formative plumage - the first set of plumage after juvenile, produced by the preformative molt

Greater coverts - the lowest level of feathers overlapping the secondaries

Incomplete molt - a molt in which at least some primaries, secondaries, and/or rectrices are replaced, but at least some are also retained

Juvenile (also “juvenal”) plumage - the first full set of feathers following the replacement of natal down

Lesser coverts - the uppermost level of feathers on the inner wing, overlapping the median coverts

Median coverts - the middle level of feathers on the inner wing, overlapping the greater coverts

Molt (also “moult”) - the systematic replacement of feathers

Molt cycle - the period between prebasic molts, usually considered to start and end with the replacement of the first primary

P10 - the outermost primary on many species (others have only nine), often substantially shorter than the other primaries

Partial molt - a molt limited to the body feathers, often at least some wing coverts, and rarely some to all tertials and/or the central rectrices, but no primaries or secondaries

Prealternate molt - a molt (typically partial) that result in alternate plumage

Prebasic molt - a molt (often complete or nearly so) that results in basic plumage

Preformative molt - a molt (most commonly partial to incomplete, but complete in some species) that results in formative plumage

Prejuvenile molt - a complete molt through which natal down is replaced with the first full set of full feathers

Primaries - the flight feathers on the outer half of the wing, connected to the manus; most commonly there are nine or ten primaries, numbered from the centre of the wing to the outer edge

Primary coverts - the set of feathers covering the upper portion of the primaries

Rectrices - the tail feathers, numbered in pairs outward from the centre (e.g., r1 to r6 in most passerines) Caudales

Reference image - an image that has been selected by Piranga editors as the best available representation of the typical appearance of a given age/sex class

Secondaries - flight feathers on the inner half of the wing, connected to the ulna, ranging from as few as 6 in hummingbirds to as many as 40 in some albatrosses, and numbered from the centre of the wing inwards

Supplemental image - an image that has been selected by Piranga editors as representing a distinct variation in appearance compared to what is shown by the corresponding reference image

Tertials - typically used to refer to the innermost three secondaries

Undertail coverts - the feathers, often somewhat large and loose that cover the region between the lower belly and the tail

Underwing coverts - the rows of feathers lining the underside of the wing, most notably from a molt perspective the upper/inner tracts

Uppertail coverts - small feathers above the base of the tail