McGILL BIRD OBSERVATORY

PHOTO LIBRARY

Common Yellowthroat / Paruline masquée (Geothlypis trichas)

 NOTE: This species account has been moved to Piranga to allow for improved comparison among examples.  
The updated profile is located at: http://www.natureinstruct.org/piranga/view.php/Canada/BA4C8A02839564AC 

QUICK TIPS:
1) Look at the face - only males have a black mask, but note that in addition to females, some HY males may also be entirely lacking black

2) Look at the tail - HY/SY birds have uniformly narrow and pointed rectrices OR replaced central rectrices contrasting with the remaining older rectrices, while AHY/ASY birds have uniformly broad and relatively rounded rectrices

3) Look at the primary coverts - on HY/SY birds they are browner and more worn than the greater coverts, while on AHY/ASY birds they are uniform in colour and wear with the greater coverts; however, the contrast on HY/SY birds can be quite subtle, and should not be used as the sole ageing criterion unless it is particularly distinct

Species account updated April 2009

Ageing and sexing guidelines:

January - July:

ASY - M
Black facial mask; relatively broad and rounded rectrices; no moult limit between primary coverts and greater coverts

ASY - F
Lacking black; relatively broad and rounded rectrices; no moult limit between primary coverts and greater coverts; throat pale to bold yellow

SY - M
Black facial mask; relatively narrow, pointed, and worn rectrices; moult limit between brownish primary coverts and more olive-tinged greater coverts
SY - F
Lacking black; relatively narrow, pointed, and worn rectrices; moult limit between brownish primary coverts and more olive-tinged greater coverts; throat buff to pale yellow

-

June - December:

AHY - M
Black facial mask; relatively broad and rounded rectrices; no moult limit between primary coverts and greater coverts 
AHY - F
Lacking black; relatively broad and rounded rectrices; no moult limit between primary coverts and greater coverts; throat pale to bold yellow
HY - M
Partial black facial mask; relatively narrow, pointed, and worn rectrices; moult limit between brownish primary coverts and more olive-tinged greater coverts
HY - U (mostly females, some males)
Lacking black; relatively narrow, pointed, and worn rectrices; moult limit between brownish primary coverts and more olive-tinged greater coverts; throat buff to pale yellow
 

Ageing and sexing details:

JAN - JUL:  after-second-year male

Males are easily recognized in spring by their distinctive black facial mask.  Close examination of the wing and/or tail is usually required to determine age.  Note that there may be a fair amount of variation in extent of yellow on the breast, as shown in the photos below; this represents regional and/or individual variation, and should therefore not be used as an indicator of age.


Photo by Marcel Gahbauer, McGill Bird Observatory (QC), May 2005


Photo by Peter Pyle, Southeast Arizona, June 2007


On after-second-year Common Yellowthroats, the primary coverts have a distinctive greenish outer edge, and tend to be somewhat more broad and rounded than those of second-year birds, but the difference can be subtle and should not be the only criterion considered.


Photo by Peter Pyle, Southeast Arizona, June 2007


 
Photo by Barbara Frei, McGill Bird Observatory (QC), May 2008


Photo by Marcel Gahbauer, McGill Bird Observatory (QC), May 2005


Largely because they spend more time in denser ground vegetation than most other warblers, the rectrices of Common Yellowthroats can appear rather worn and tattered by spring, regardless of age.  However, the wear tends to be less severe on after-second-year birds, and the feathers are also typically broader and more rounded toward the tip, though as the second photo below shows, the wear on the feathers may make that distinction difficult to assess reliably.


 
Photo by Barbara Frei, McGill Bird Observatory (QC), May 2008


Photo by Marcel Gahbauer, McGill Bird Observatory (QC), May 2005

RETURN TO AGE/SEX OVERVIEW

JAN - JUL:  after-second-year female

Females are easily recognized in spring by the lack of any black on the face, but close examination of the wing and/or tail is usually required to determine age.


Photo by Marcel Gahbauer, McGill Bird Observatory (QC), May 2006
 


On after-second-year Common Yellowthroats, the primary coverts have a distinctive greenish outer edge, and tend to be fairly broad and rounded.   However, the appearance of some second-year birds is quite similar, so this criterion should be combined with others to determine age.


Photo by Marcel Gahbauer, McGill Bird Observatory (QC), May 2006


 
  Photo by Peter Pyle, Howell Woods (NC), May 2006


Largely because they spend more time in denser ground vegetation than most other warblers, the rectrices of Common Yellowthroats can appear rather worn and tattered by spring, regardless of age.  However, the wear tends to be less severe on after-second-year birds, and the feathers are also typically broader and more rounded toward the tip, though the wear on the feathers may make that distinction difficult to assess reliably.


Photo by Marcel Gahbauer, McGill Bird Observatory (QC), May 2006

RETURN TO AGE/SEX OVERVIEW

JAN - JUL:  second-year male

Males are easily recognized in spring by their distinctive black facial mask, but close examination of the wing and/or tail is usually required to determine age.  Sometimes on second-year males the mask is slightly patchy, as in the photo below, but confirming the age with other features is strongly recommended.


Photo by Marcel Gahbauer, McGill Bird Observatory (QC), May 2006


On second-year Common Yellowthroats there is usually a moult limit between the primary coverts and the greater coverts, but the contrast is often slight and easily overlooked, as the photo below illustrates.  Where it is distinct, it can be taken as a reliable indicator of age, but in most cases the tail will provide a clearer clue, and ideally both should be assessed in tandem. Note that some individuals (as in the second photo below) undergo an eccentric preformative moult, in which some primaries and/or secondaries are replaced, with the resulting moult limit still easily visible in spring as a contrast between the fresher green-edged feathers and browner, more worn juvenile feathers.


 
Photo by Peter Pyle, Big Sur Ornithological Lab (CA), May 2007


Photo by Peter Pyle, MerryLea (IN), May 2007
 


The first photo below shows the condition of severe wear that many second-year Common Yellowthroat tails are showing by spring, with tattered edges and very pointed tips; the tail in the second photo shows slightly less wear, but the rectrices are even more pointed.  In both cases, uniform growth bars can be seen across the tail, indicating that the feathers grew simultaneously (as is the case when the first set of rectrices grows in, but not with subsequent moults).  While useful if visible, they are not always present or visible, so their absence should not be taken as an indicator of after-second-year.


Photo by Marcel Gahbauer, McGill Bird Observatory (QC), May 2006


Photo by Marcel Gahbauer, McGill Bird Observatory (QC), May 2006

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JAN - JUL:  second-year female

Females are easily recognized in spring by the lack of any black on the face, but close examination of the wing and/or tail is usually required to determine age. Note, however, that on this bird the throat is particularly pale and the greater alula appears quite pale and frayed at the edge.  Both of these features suggest that it is a second-year female, but checking the wing and tail for confirmation is strongly recommended.


Photo by Marcel Gahbauer, McGill Bird Observatory (QC), May 2005
 


On second-year Common Yellowthroats there is usually a moult limit between the primary coverts and the greater coverts, but the contrast is often slight and easily overlooked, as the photo below illustrates.  Where it is distinct, it can be taken as a reliable indicator of age, but in most cases the tail will provide a clearer clue, and ideally both should be assessed in tandem.  Note also the often poor condition of the primaries and secondaries by spring, especially when looking at the tips of the feathers.


Photo by Marcel Gahbauer, McGill Bird Observatory (QC), May 2005


Photo by Peter Pyle, Southeast Arizona, June 2007


This photo illustrates the fact that some Common Yellowthroats replace their central rectrices in their first prebasic moult - note how they are fairly rounded and in good condition, compared with the five left outer rectrices that are paler, more tattered, and at least in some cases relatively pointed.  After-second-year birds will have replaced all rectrices during their moult, so a "mixed" tail such as this is a good sign of a second-year bird.


Photo by Marcel Gahbauer, McGill Bird Observatory (QC), May 2005

RETURN TO AGE/SEX OVERVIEW

JUN - DEC:  after-hatch-year male

After-hatch-year males are generally quite easy to recognize in fall as they are the only age/sex class with an extensive black mask.  However, there is some potential for confusion between after-hatch-year males with particularly mottled facial patches and hatch-year males with unusually extensive black flecking, and especially in such cases the wing and tail should be examined closely to confirm age.  The two photos below are of the same individual, one year apart; in 2006 it had nearly completed its prebasic moult already, while in 2007 it was still well underway at the time photos were taken.


Photo by Seabrooke Leckie, McGill Bird Observatory (QC), August 2006


Photo by Marie-Anne Hudson, McGill Bird Observatory (QC), August 2007
 


On after-hatch-year Common Yellowthroats, the primary coverts have a distinctive greenish outer edge, and all of them are fairly broad and rounded, as shown in the first photo below.   However, the appearance of some second-year birds is quite similar, so this criterion is of relatively limited value.  Especially in early fall, some birds may be seen with primaries and/or secondaries being replaced, and this is also suggestive of after-hatch-year, though some hatch-year birds do replace some of these feathers as part of an eccentric preformative moult.

 
Photo by Peter Pyle, La Mancha (Mexico), October 2006


Photo by Seabrooke Leckie, McGill Bird Observatory (QC), August 2006


Photo by Marie-Anne Hudson, McGill Bird Observatory (QC), August 2007


After-hatch-year Common Yellowthroats have relatively broad and rounded outer rectrices, but they may become fairly rapidly worn due to the dense habitat they prefer.  Note that in the example below some of the individual rectrices have a fairly distinct tip, but that most feathers remain fairly broad to near it, rather than tapering gradually toward the tip as is more typical for hatch-year birds.  Nonetheless, it can be confusing enough that it re-emphasizes that this is a species for which multiple characteristics should be combined to determine age.  The second photo shows the same individual one year later, and it appears to have not yet moulted its tail.


Photo by Seabrooke Leckie, McGill Bird Observatory (QC), August 2006


Photo by Marie-Anne Hudson, McGill Bird Observatory (QC), August 2007

RETURN TO AGE/SEX OVERVIEW

JUN - DEC:  after-hatch-year female

Typical after-hatch-year females are moderately recognizable in fall, as they lack any black on the face yet have a distinctly yellow throat.  Beware, however, some hatch-year males that have not yet acquired any black in the face.  Checking the wing and tail to determine age will help resolve this uncertainty.


Photo by Marcel Gahbauer, McGill Bird Observatory (QC), September 2005


 
Photo by Marcel Gahbauer, McGill Bird Observatory (QC), August 2008


On after-hatch-year Common Yellowthroats, the primary coverts have a distinctive greenish outer edge, and all of them are fairly broad and rounded.   However, the appearance of some second-year birds is quite similar, so this criterion is of relatively limited value.  Sequential replacement of all primaries and secondaries (as shown in the second photo below) is also indicative of after-hatch-year birds, but beware that some hatch-year individuals may undergo an eccentric moult of some of these feathers.


Photo by Marcel Gahbauer, McGill Bird Observatory (QC), September 2005


 
  Photo by Marcel Gahbauer, McGill Bird Observatory (QC), August 2008


After-hatch-year Common Yellowthroats have relatively broad and rounded outer rectrices, but they may become fairly rapidly worn due to the dense habitat they prefer.  Note that in the example below some of the individual rectrices have a fairly distinct tip, but that most feathers remain fairly broad to near it, rather than tapering gradually toward the tip as is more typical for hatch-year birds.  Nonetheless, it can be confusing enough that it re-emphasizes that this is a species for which multiple characteristics should be combined to determine age.


  Photo by Marcel Gahbauer, McGill Bird Observatory (QC), August 2008

RETURN TO AGE/SEX OVERVIEW

 

JUN - DEC:  hatch-year male

Typically hatch-year males have some black flecking in the area of the facial mask.  However, in some it may be extensive enough to overlap with relatively pale after-hatch-year males, and in other cases they may not yet have any black at all and could be confused with after-hatch-year females.  In both cases, looking closely at the wing and tail for other clues to determine age should resolve most questions.


Photo by Marcel Gahbauer, McGill Bird Observatory (QC), August 2005
 


On hatch-year Common Yellowthroats there is a moult limit between the primary coverts and the greater coverts, but the contrast is often slight and easily overlooked, though in the photo below it is actually apparent.  In cases such as this where it is distinct, it can be taken as a reliable indicator of age, but in most cases the tail will provide a clearer clue, and ideally both should be assessed in tandem.


Photo by Seabrooke Leckie, McGill Bird Observatory (QC), September 2006
 


Hatch-year Common Yellowthroats have relatively narrow rectrices that are tapered to a pointed tip, though only rarely is the shape as extreme as in the example below.


Photo by Marcel Gahbauer, McGill Bird Observatory (QC), August 2005

RETURN TO AGE/SEX OVERVIEW

JUN - DEC:  hatch-year unknown (female?)

Common Yellowthroats identified as hatch-year through wing and tail characteristics, but lacking any black on the face, are most likely to be females.  However, as some hatch-year males do not have any black on the face either, these should generally be considered as sex unknown. The intensity of yellow in the second example below is suggestive of a male.


Photo by Marcel Gahbauer, McGill Bird Observatory (QC), August 2007


Photo by Marcel Gahbauer, McGill Bird Observatory (QC), September 2005
 


On second-year Common Yellowthroats there is a moult limit between the primary coverts and the greater coverts, but the contrast is often slight and easily overlooked, as the photo below illustrates.  Where it is distinct, it can be taken as a reliable indicator of age, but in most cases the tail will provide a clearer clue, and ideally both should be assessed in tandem. 


Photo by Marcel Gahbauer, McGill Bird Observatory (QC), August 2007
 


Hatch-year Common Yellowthroats have relatively narrow rectrices that are tapered to a pointed tip. Note, however, that Common Yellowthroats are particularly likely to replace some or all of their rectrices prematurely; the second photo below shows an example of two new rectrices growing in, with distinctly denser barbs and more rounded tips than the retained juvenile feathers.


Photo by Marcel Gahbauer, McGill Bird Observatory (QC), September 2005


  Photo by Marcel Gahbauer, McGill Bird Observatory (QC), August 2008

RETURN TO AGE/SEX OVERVIEW 

2002- The Migration Research Foundation Inc.