White-throated Sparrows can be relatively difficult to age, since age-related differences in wing and tail patterns are often subtle; especially by spring, a fair number of intermediates cannot be reliably aged. Sex can generally be determined only by brood patch / cloacal protuberance during the breeding season, or by particularly short or long wing chords (<67 mm = female, >74 mm = male).
There are white-striped and tan-striped morphs of this species which look considerably different; while differences in head colouration are to some degree related to age and sex, they mostly overlap too much to be of use. Also beware that juveniles can appear quite similar to Song Sparrows, but usually have a larger wing chord and greater weight.
Species account prepared by McGill Bird Observatory
|Age / Sex||Image sets|
|Hatch year / Unknown
Gray-brown iris; sometimes lightly streaked breast; relatively dull primary coverts; rectrices relatively narrow and tapered
|After hatch year / Unknown
Reddish-brown iris; unstreaked breast; wing largely uniform in colour, with broad, dark outer primary coverts; rectrices relatively broad and rounded;
|Age / Sex||Age / Sex class description|
|Juvenile / Unknown||Streaked breast; limited coloration to coverts; narrow but fresh rectrices.|
|Second year / Unknown||Indistinct molt limit between greater coverts vs. primary coverts, primaries, secondaries, and tertials; outer primary coverts dull; rectrices relatively narrow and tapered|
|After second year / Unknown||Wing largely uniform in colour, with broad, dark outer primary coverts; rectrices relatively broad and rounded|