PHOTO LIBRARY

Bicknell's Thrush (Catharus bicknelli)

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC

common   fairly common   uncommon   rare   occasional   no records

 

QUICK TIPS: 1) Look at the greater coverts - the presence of buffy-white shaft streaks indicates a HY/SY bird, however the absence of buffy-white shaft streaks is NOT an entirely reliable indicator of AHY/ASY, as some HY/SY birds may lack these markings 2) Examine the outermost primary (p10) - on HY/SY birds it is rounded and 0-6 mm shorter than the primary coverts, while on AHY/ASY birds it is narrow, pointed, and 4-10 mm shorter than the primary coverts 3) Look at the shape of the rectrices - they are tapered and relatively abraded on HY/SY birds, but rounded and relatively fresh on AHY/ASY birds

January - July:

ASY - U Broad and rounded rectrices; outermost primary (p10) narrow and pointed. SY - U Pale shaft streaks on outer greater coverts; rectrices narrow, tapered, and relatively worn; p10 broad and rounded

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June - December:

AHY - U Broad and rounded rectrices; outermost primary (p10) narrow and pointed.       HY - U Pale shaft streaks on outer greater coverts; rectrices narrow, tapered, and relatively worn; p10 broad and rounded

 

Ageing and sexing details:

The overall appearance of Bicknell's Thrush provides few clues to age or sex, but the relatively extensive yellow on the lower mandible is a good clue to the species, to be used in combination with the overall olive-brown appearance and contrastingly rusty-chestnut tinged tail.

Photo by Marcel Gahbauer, McGill Bird Observatory, May 2005
 

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Greater coverts uniform in colour and wear, and lacking pale tips or shaft streaks, are suggestive of an after-second-year bird, but the length and shape of the outermost primary (p10) should be used to confirm age (not visible in this photo).

Photo by Marcel Gahbauer, McGill Bird Observatory, May 2005

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The relatively broad and rounded rectrices are typical of after-second-year thrushes.

Photo by Marcel Gahbauer, McGill Bird Observatory, May 2005

RETURN TO AGE/SEX OVERVIEW

 

second-year unknown

 

after-hatch-year unknown

hatch-year unknown