Ageing and sexing details:
|
JAN - JUL: after-second-year
unknown |
Body plumage provides no useful information
about age or sex of Savannah Sparrows, though occasionally the condition of wing feathers can be visible on a perched bird. Sex can be determined only during the breeding
season by brood patch or cloacal protuberance.
Photo by Marcel Gahbauer,
McGill Bird Observatory (QC), April 2006
Photo by Barbara Frei, McGill Bird Observatory (QC),
May 2007
Primary coverts are dark brown on ASY birds, relatively uniform in colour and wear with the rest of the wing. They are usually broad and
rounded, but differences between age classes are rather subtle in this species, so shape must be interpreted with caution.
Photo by Barbara Frei, McGill Bird Observatory (QC),
May 2007
Photo by Marcel Gahbauer,
McGill Bird Observatory (QC), April 2006
Tail shape is a good indicator of age for Savannah Sparrows, as SY birds
have narrow and very tapered outer rectrices, while ASY birds have
broader and relatively truncate rectrices. Note, however, that SY birds may occasionally replace their entire tail, and therefore broad and truncate rectrices should not be used as the only criterion for ageing a bird ASY.
Photo by Barbara Frei, McGill Bird Observatory (QC),
May 2007
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OVERVIEW
|
JAN - JUL: second-year
unknown |
Body plumage provides no useful information
about age or sex, although sometimes the condition of the wing feathers can be seen on a perched bird (as in the photo below). Sex can be determined only during the breeding
season by brood patch or cloacal protuberance.
Photo by Marie-Anne Hudson,
McGill Bird Observatory (QC), May 2007
Photo by Marie-Anne Hudson, McGill Bird Observatory (QC),
May 2008
Primary coverts are dull brown on SY birds, and usually look relatively
narrow, tapered, and abraded. The primary coverts are uniform in colour and wear with the primaries and secondaries, and these juvenile feathers as a block contrast with the darker and fresher formative greater coverts.
Photo by Marie-Anne Hudson,
McGill Bird Observatory (QC), May 2007
Photo by Barbara Frei, McGill Bird Observatory (QC),
May 2007
Photo by Marie-Anne Hudson, McGill Bird Observatory (QC),
May 2008
Tail shape is a good indicator of age for Savannah Sparrows, as SY birds
usually have narrow and very tapered outer rectrices, while ASY birds have
broader and relatively truncate rectrices. Note that in the
first example below, the bird has replaced several of its central rectrices
(r1 to r3 on both sides) while retaining the outermost juvenile
rectrices (r4 to r6 on either side), while in the second photo only r1 has been replaced, and sometimes all rectrices are juvenile.
Photo by Marie-Anne Hudson,
McGill Bird Observatory (QC), May 2007
Photo by Barbara Frei, McGill Bird Observatory (QC),
May 2007
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OVERVIEW
|
JUL - DEC: after-hatch-year
unknown |
Body plumage provides no useful information
about age or sex. Sex can be determined only during the breeding
season by brood patch or cloacal protuberance. Note that there is considerable variation in Savannah Sparrow plumage, with the example below being a rather dark specimen.
Photo by Barbara Frei, McGill Bird Observatory (QC),
September 2007
Primary coverts are relatively dark brown on AHY birds, and relatively broad and
rounded; note that even on after-hatch-year birds, the primary coverts are somewhat lighter in colour than the greater coverts.
Photo by Barbara Frei, McGill Bird Observatory (QC),
September 2007
Tail shape is a good indicator of age for Savannah Sparrows, as HY birds
have narrow and very tapered outer rectrices, while AHY birds have
broader and relatively truncate rectrices.
Photo by Barbara Frei, McGill Bird Observatory (QC),
September 2007
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OVERVIEW
|
JUL - DEC: hatch-year
unknown |
Body plumage provides no useful information
about age, and sex cannot be determined for HY birds.
Photo by Seabrooke Leckie,
McGill Bird Observatory (QC), August 2006
Photo by James Junda, McGill Bird Observatory (QC),
September 2008
Primary coverts are dull brown on SY birds, and usually look relatively
narrow and tapered.
Photo by Seabrooke Leckie,
McGill Bird Observatory (QC), August 2006
Photo by James Junda, McGill Bird Observatory (QC),
September 2008
Tail shape is a good indicator of age for Savannah Sparrows, as HY birds
have narrow and very tapered outer rectrices, while AHY birds have
broader and relatively truncate rectrices.
Photo by Seabrooke Leckie,
McGill Bird Observatory (QC), August 2006
Photo by James Junda, McGill Bird Observatory (QC),
September 2008
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OVERVIEW
