English  | Français  | Español
Lists:  MEX        
Number of species: 71

Select a species:

  
 
:   Clear  

White-throated Sparrow - Zonotrichia albicollis

White-throated Sparrow has a partial preformative molt, and limited prealternate molts that are largely restricted to feathers on the head. This species can be difficult to age, as differences in plumage can be subtle, and especially by spring, some individuals appear sufficiently intermediate that they should be considered M-FCU (AHY). 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; although 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.

Quick tips

  • Look at the tail - uniformly narrow and pointed rectrices are indicative of FCF/FCU (HY/SY), while broad and more rounded rectrices are typical of DCB/DCU (AHY/ASY).
  • In fall, examine the iris in good light - it is grayish-brown in FCF (HY) birds, compared to brown (sometimes with a slight reddish tinge) in DCB (AHY) birds.
  • Check the wing for molt limits - FCF/FCA (HY/SY) birds should show a contrast between darker/fresher greater coverts and the paler block of primary coverts, primaries, and secondaries, but this tends to be more apparent in spring and even then can sometimes be too subtle to distinguish from the pseudolimit typical of DCB/DCA (AHY/ASY) birds.

Species account prepared by McGill Bird Observatory (2016). Last updated by Marcel Gahbauer (Mar 2022)

The molt categories displayed below may be filtered by month.

    Clear

Click on any image below to bring up the side-by-side comparison tool.

Individuals not in molt

FCJ - (HY: June - August)
Head relatively dark and indistinctly patterned; breast coarsely streaked
U
Thumbnail - MG2-2341-58731-Zonotrichia_albicollis_AOU_7_52-2005.jpg Thumbnail - MG2-2341-58731-Zonotrichia_albicollis_AOU_7_52-2007.jpg Thumbnail - MG2-2341-58731-Zonotrichia_albicollis_AOU_7_52-2006.jpg
FCF - (HY: July - December; SY January - April)
Rectrices narrow and pointed; iris grayish-brown until mid-winter; greater coverts contrastingly darker and fresher than primary coverts, primaries, and secondaries, especially by late winter
U
Thumbnail - MG2-2431-74820-Zonotrichia_albicollis_AOU_7_52-2002.jpg Thumbnail - MG2-2431-74820-Zonotrichia_albicollis_AOU_7_52-2004.jpg Thumbnail - MG2-2431-74820-Zonotrichia_albicollis_AOU_7_52-2003.jpg
FCU - (SY: March - August)
Rectrices narrow and pointed; iris brown to reddish-brown; greater coverts contrastingly darker and fresher than primary coverts, primaries, and secondaries
U
Thumbnail - MG2-2241-39654-Zonotrichia_albicollis_AOU_7_52-2008.jpg Thumbnail - MG2-2241-39654-Zonotrichia_albicollis_AOU_7_52-2010.jpg Thumbnail - MG2-2241-39654-Zonotrichia_albicollis_AOU_7_52-2009.jpg
DCB - (AHY: July - December; ASY January - April)
Rectrices uniformly broad and rounded; iris reddish-brown; wing largely uniform in colour and wear, with secondaries and primary coverts only slightly lighter than greater coverts
U
Thumbnail - MG2-1541-17951-Zonotrichia_albicollis_AOU_7_52-1996.jpg Thumbnail - MG2-1541-17951-Zonotrichia_albicollis_AOU_7_52-1998.jpg Thumbnail - MG2-1541-17951-Zonotrichia_albicollis_AOU_7_52-1997.jpg
DCU - (ASY: March - August)
Rectrices uniformly broad and rounded; iris reddish-brown; wing largely uniform in colour and wear, with secondaries and primary coverts only slightly lighter than greater coverts
U
Thumbnail - MG2-2241-39630-Zonotrichia_albicollis_AOU_7_52-1999.jpg Thumbnail - MG2-2241-39630-Zonotrichia_albicollis_AOU_7_52-2001.jpg Thumbnail - MG2-2241-39630-Zonotrichia_albicollis_AOU_7_52-2000.jpg

Individuals in active molt

FPJ - (HY: June - August)
Similar to FCJ; some natal down remaining and/or juvenile flight feathers still growing in
No images available yet
FPF - (HY: July - September)
Similar to FCF; median and greater coverts and in some cases also tertials and central rectrices being replaced
No images available yet
FPA - (SY: March - May)
Similar to FCF; some head and other body feathers being replaced
No images available yet
SPB - (SY: July - September)
Flight feathers being replaced, with retained juvenile primaries, secondaries, and/or primary coverts distinctly pale brown and very worn
No images available yet
DPB - (AHY: July - September)
Flight feathers being replaced, with retained primaries, secondaries, and/or primary coverts either distinctly adult (relatively dark, less worn) or intermediate
No images available yet
DPA - (ASY: March - May)
Similar to DCB; some head and body feathers being replaced
No images available yet

Applicable unknown plumage/age classes

Molt classes Age Months Key traits
M-FPF / UPU (FPF, SPB, DPB) U July - September Undergoing preformative or prebasic molt, but cycle is not reliably distinguishable
M-FCF / UCU (FCF, SCB, DCB) U/AHY July - April In formative or basic plumage (molt completed), but cycle is not reliably distinguishable
M-FPA / UPA (FPA, DPA) AHY March - May Undergoing prealternate molt, but cycle is not reliably distinguishable
M-FCU / UCU (FCU, DCU) AHY March - August In formative, basic, or alternate plumage (molt completed), but cycle and plumage are not reliably distinguishable