White-crowned Sparrow is easy to age reliably in fall simply by the head pattern; in spring this is rarely helpful, but wing and tail can be used to age most individuals. Sex can usually be determined only by brood patch / cloacal protuberance during the breeding season, although particularly small or large wing chords (varying by subspecies) may be indicative of sex for a minority of birds.
The five recognized subspecies differ somewhat in appearance and extent of molt, but the overall patterns are sufficiently consistent for ageing/sexing guidelines to apply to all of them
Species account prepared by McGill Bird Observatory
|Age / Sex||Image sets|
|After hatch year / Unknown
Black and white crown stripes; wing uniform in colour and wear; rectrices relatively broad and rounded.
|Second year / Unknown
Molt limit on the wing between the greater coverts and paler brown primary coverts, primaries, and secondaries; at least some retained juvenile rectrices showing wear
|Age / Sex||Age / Sex class description|
|Hatch year / Unknown||Brown and tan crown stripes; slight contrast between the greater coverts and the rest of the wing; rectrices relatively narrow and tapered.|
|Juvenile / Unknown||Some streaking on the breast; wing uniformly pale brown (or with greater coverts being replaced); rectrices relatively narrow and tapered.|
|After second year / Unknown||Wing largely uniform in colour and wear; rectrices relatively broad and rounded.|