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Number of species: 79

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Snow Bunting - Plectrophenax nivalis

Snow Bunting has a partial preformative molt and no prealternate molts. However, as feather tips wear off over time, such that overall appearance is quite different between fall/winter and spring/summer. Molt limits are subtle in this species, and age-related differences in plumage are somewhat more subtle in females. Sex of most individuals is easily determined by plumage.

Quick tips

  • Check the shape of the rectrices - on FCF (HY/SY) birds they are narrow and pointed while on DCB (AHY/ASY) birds they tend to be more broad and rounded.
  • Look at the primary coverts - on DCB (AHY/ASY) males they are entirely white or with only small black spots near the tips, on FCF (HY/SY) males they tend to be white with blackish tips, occasionally extending up the shaft, on DCB (AHY/ASY) females the tips are dark but inner webs are largely white, and on FCF (HY/SY) females they are largely blackish with white limited to the upper inner webs.
  • Examine the median coverts, which are largely white on males and black (sometimes with white borders) on females.

Species account prepared by McGill Bird Observatory (2018). Last updated by Marcel Gahbauer (Mar 2022)

The molt categories displayed below may be filtered by month.

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

Individuals not in molt

FCJ - (HY: July - August)
Dark grayish with streaked underparts
No images available yet
FCF - (HY/SY: July - following September)
Rectrices somewhat narrow and pointed; primary coverts whitish with small to moderate black tips (M) or largely blackish (F); median coverts mostly white (M) or mix of black and white (F)
M
Thumbnail - AA3-NA_626-Plectrophenax_nivalis_AOU_7_52-1208.jpg Thumbnail - AA3-NA_626-Plectrophenax_nivalis_AOU_7_52-1207.jpg
F
Thumbnail - AA3-NA_627-Plectrophenax_nivalis_AOU_7_52-1209.jpg
DCB - (AHY/ASY: July - following September)
Rectrices mostly broad and rounded; primary coverts mostly to entirely white (M) or mostly blackish (F); median coverts white (M) or mostly blackish (F); secondaries bold white (M) or whitish with dusky tips (F)
M
Thumbnail - AA3-NA_625-Plectrophenax_nivalis_AOU_7_52-1206.jpg Thumbnail - AA3-NA_625-Plectrophenax_nivalis_AOU_7_52-1205.jpg

Individuals in active molt

FPJ - (HY: July - 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 being replaced
No images available yet
SPB - (SY: July - September)
Flight feathers being replaced, with retained juvenile primaries, secondaries, and/or primary coverts (see FCF)
No images available yet
DPB - (AHY: July - September)
Flight feathers being replaced, with retained primaries, secondaries, and/or primary coverts either distinctly adult (see DCB) or intermediate
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 January - December In formative or basic plumage (molt completed), but cycle is not reliably distinguishable

Number of species: 79

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