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Number of species: 74

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Savannah Sparrow - Passerculus sandwichensis

Savannah Sparrow has a partial preformative molt, and limited to incomplete prealternate molts. Many individuals can be aged using molt limits and rectrix shape, but by spring a fair number of intermediates cannot be reliably aged and should be considered M-FCA (AHY). Although females are on average slightly smaller than males, sex of most individuals is reliably determined only by brood patch / cloacal protuberance during the breeding season.

Quick tips

  • Look at the tail - uniformly narrow and pointed rectrices OR contrastingly fresh and broad central rectrices are indicative of FCF/FCA (HY/SY), while uniformly broad and more rounded rectrices are typical of DCB/DCA (AHY/ASY).
  • Check the outer primary coverts - they are relatively narrow and pointed and medium brown on FCF/FCA (HY/SY) birds, compared to relatively broad and rounded and dark brown on 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.

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

Individuals not in molt

FCJ - (HY: June - August)
Similar to FCF but with wing bars slightly more pronounced
No images available yet
FCF - (HY: July - December; SY January - March)
Rectrices narrow and pointed; primary coverts narrow and pointed and contrastingly pale compared to greater coverts
U
Thumbnail - MG2-9901-00002-Passerculus_sandwichensis_AOU_7_52-1893.jpg Thumbnail - MG2-9901-00002-Passerculus_sandwichensis_AOU_7_52-1895.jpg Thumbnail - MG2-9901-00002-Passerculus_sandwichensis_AOU_7_52-1894.jpg
FCU - (SY: March - September)
Rectrices all narrow and pointed or mixed with contrastingly fresh and more rounded central rectrices; primary coverts narrow and pointed and contrastingly pale compared to greater coverts
No images available yet
DCB - (AHY: July - December; ASY January - March)
Rectrices uniformly broad and rounded; wing largely uniform in colour and wear, with primary coverts relatively broad, rounded, and dark brown, showing only a slight contrast with greater coverts
U
Thumbnail - MG2-2221-82028-Passerculus_sandwichensis_AOU_7_52-1887.jpg Thumbnail - MG2-2221-82028-Passerculus_sandwichensis_AOU_7_52-1889.jpg Thumbnail - MG2-2221-82028-Passerculus_sandwichensis_AOU_7_52-1888.jpg
DCU - (ASY: March - September)
Rectrices uniformly broad and rounded; wing largely uniform in colour and wear, with primary coverts relatively broad, rounded, and dark brown, showing only a slight contrast with greater coverts
No images available yet

Individuals in active molt

FPJ - (HY: June - August)
Similar to FCF but with wing bars slightly more pronounced; some natal down remaining
No images available yet
FPF - (HY: July - September)
Similar to FCF; median and greater coverts and often also tertials being replaced
No images available yet
FPA - (SY: February - April)
Similar to FCF; some body feathers being replaced as well as tertials and central rectrices on some individuals
No images available yet
SPB - (SY: July - September)
Flight feathers being replaced, with retained rectrices or outer primaries and primary coverts distinctly juvenile (pale brown and very worn)
No images available yet
DPB - (AHY: July - September)
Flight feathers being replaced, with retained rectrices or outer primaries and primary coverts either distinctly adult (relatively dark, less worn, somewhat broad and rounded) or intermediate
No images available yet
DPA - (ASY: February - April)
Similar to DCB; some body feathers being replaced as well as tertials and central rectrices on some individuals
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 - March In formative or basic plumage (molt completed), but cycle is not reliably distinguishable
M-FPA / UPA (FPA, DPA) AHY February - April Undergoing prealternate molt, but cycle is not reliably distinguishable
M-FCU / UCU (FCU, DCU) AHY March - September In formative, basic, or alternate plumage (molt completed), but cycle and plumage are not reliably distinguishable

Number of species: 74

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