Migration Research Foundation - McGill Bird Observatory - Photo Library

McGILL BIRD OBSERVATORY

PHOTO LIBRARY

Canada Warbler / Paruline du Canada (Wilsonia canadensis)

Seasonal status at MBO:

JAN

FEB

MAR

APR

MAY

JUN

JUL

AUG

SEP

OCT

NOV

DEC

common

fairly common

uncommon

rare

occasional

no records

QUICK TIPS:

1) Examine the forehead - it is moderately to extensively black on all AHY/ASY males and SY males, and has black flecks on some ASY females and HY males, but is greenish-gray and lacking black on HY/SY females and other ASY females and HY males

2) Look for moult limits on the wing - on AHY/ASY birds the wing is uniformly gray, while on HY/SY birds there is often a visible contrast between the gray greater coverts and brownish-gray primary coverts, primaries, and secondaries.

3) Look at the rectrices - on HY/SY birds they are relatively narrow and pointed, while on AHY/ASY birds they are relatively broad and rounded; note though that there is a fair amount of variation, therefore only extremes may be useful in helping with ageing

Species account updated May 2009

Ageing and sexing overview:

January - July:

ASY - M Forehead and lores black; distinct black necklace; wing uniformly gray; rectrices relatively broad and rounded
ASY - F Forehead and lores grayish, with or without black flecks; necklace dusky but relatively distinct; wing uniformly gray; rectrices relatively broad and rounded
SY - M Forehead and lores black; moderately distinct black necklace; brownish primary coverts contrasting with gray greater coverts; rectrices relatively narrow, pointed, and worn
SY - F Forehead and lores grayish-green, lacking black; necklace gray and indistinct; brownish primary coverts contrasting with gray greater coverts; rectrices relatively narrow, pointed, and worn

July - December:

AHY - M Forehead and lores black; moderately distinct dusky to black necklace; wing uniformly gray; rectrices relatively broad and rounded
AHY - F Forehead and lores gray, sometimes with black flecks; necklace dusky and usually incomplete; wing uniformly gray; rectrices relatively broad and rounded
HY - M Forehead and lores gray, sometimes with black flecks; necklace dark but limited in extent; moult limit between primary and greater coverts; rectrices relatively narrow and pointed
HY - F Forehead and lores greenish-gray, lacking any black; necklace faint and incomplete; moult limit between primary and greater coverts; rectrices relatively narrow and pointed

Ageing and sexing details:

JAN - JUL: after-second-year male

After-second-year males have the greatest amount of black on the forehead, face, and necklace, but appearance can vary depend on the angle of viewing, as illustrated by the two photos of the same bird below. Therefore ageing should usually take wing and/or tail into account.

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

While the wing may appear somewhat worn by spring on Canada Warblers of all ages, the colour is relatively uniform gray on after-second-year birds.

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

The rectrices of after-second-year Canada Warblers tend to be somewhat more broad and rounded than those of second-year birds.

Photo by Marie-Anne Hudson, McGill Bird observatory (QC), May 2007

RETURN TO AGE/SEX OVERVIEW

JAN - JUL: after-second-year female

RETURN TO AGE/SEX OVERVIEW

JAN - JUL: second-year male

Second-year males tend to have somewhat less black on the forehead, and especially on the necklace, but the wing and/or tail should be examined to be confident about age. Note, however, that in some cases the contrast between brownish primary coverts and gray greater coverts can be seen on a perched bird.

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

Photo by Marie-Anne Hudson, McGill Bird Observatory (QC), May 2008

A moult limit between unreplaced brownish primary coverts (and primaries and secondaries) and the fresher gray greater coverts is a good indicator for second-year Canada Warblers. However, beware that while the contrast is very evident in some birds such as the first photo below, it can be more subtle in others, as in the second photo.

Photo by Marie-Anne Hudson, McGill Bird Observatory (QC), May 2008

Rectrices of second-year Canada Warblers tend to be somewhat narrower, more pointed, and showing greater wear than those of after-second-year birds, but there can be considerable variation, therefore moult limits on the wing are more reliable for this species.

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

Photo by Marie-Anne Hudson, McGill Bird Observatory (QC), May 2008

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JAN - JUL: second-year female

Second-year females are distinctly paler than other age/sex classes in spring, with a largely greenish-gray forehead and a faint grayish necklace.

Photo by Marie-Anne Hudson, McGill Bird Observatory (QC), May 2006

Photo by Marie-Anne Hudson, McGill Bird Observatory (QC), June 2008

Second-year Canada Warblers typically show a moult limit between unreplaced brownish primary coverts (and primaries and secondaries) and the fresher gray greater coverts, but the contrast varies from subtle to distinct.

Photo by Marie-Anne Hudson, McGill Bird Observatory (QC), June 2008

Photo by Marie-Anne Hudson, McGill Bird Observatory (QC), May 2006

Second-year Canada Warblers tend to have somewhat narrow, pointed, and worn rectrices, but there is a fair amount of variation in appearance.

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

Photo by Marie-Anne Hudson, McGill Bird observatory (QC), May 2006

RETURN TO AGE/SEX OVERVIEW

JUL - DEC: after-hatch-year male

After-hatch-year males are the only age/sex class in fall to have extensive black on the forehead and face, and to show a distinct black necklace.

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

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

After-hatch-year Canada Warblers have a uniformly gray wing.

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

The rectrices are generally relatively broad and rounded at the tip.

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

RETURN TO AGE/SEX OVERVIEW

JUL - DEC: after-hatch-year female

After-hatch-year females and hatch-year males may be relatively similar in appearance, both having a partial necklace and a largely gray forehead and face, sometimes with some black flecks. They are best separated by looking for the presence (hatch-year) or absence (after-hatch-year) of moult limits on the wing.

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

After-hatch-year females have a uniformly gray wing.

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

After-hatch-year Canada Warblers have relatively broad and rounded rectrices, but there is considerable variation; the example below is quite intermediate and of limited use in helping with ageing.

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

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JUL - DEC: hatch-year male

Hatch-year males and after-hatch-year females appear relatively similar, both having a partial necklace and a largely grayish forehead and face, often with a few black flecks. They are best distinguished by looking for the presence (hatch-year) or absence (after-hatch-year) of moult limits on the wing.

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

Moult limits on hatch-year Canada Warblers usually occur between the primary coverts and greater coverts, with the latter being bluish-gray, contrasting with the dull brownish-gray of the unreplaced primary coverts (note, however, that in early fall the colour distinction may be subtle because the primary coverts are also still relatively fresh and have not yet faded much).

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

Photo by Barbara Frei, McGill Bird Observatory (QC), August 2007

Typical hatch-year rectrices are narrow and distinctly pointed as in the photo below, but there is considerable variation in shape and some intermediates may not be useful for ageing.

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

RETURN TO AGE/SEX OVERVIEW

JUL - DEC: hatch-year female

Hatch-year females are usually readily identifiable by their greenish-gray head and minimal indistinct necklace.

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

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

Hatch-year Canada Warblers usually show a moult limit between the duller, slightly browner primary coverts and fresher, grayer greater coverts. In some cases, such as the examples below, the contrast is even more evident in that some juvenile median coverts (first photo) or greater coverts (second photo) have been retained with distinct white or buff tips.

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

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

Hatch-year Canada Warblers typically have somewhat narrower and more pointed rectrices than after-hatch-year birds, but there is considerable variation among individuals. In the third photo below, r2 through r6 on the left side have been prematurely replaced, illustrating the relatively subtle difference in shape between juvenile and adult rectrices.

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

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

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

RETURN TO AGE/SEX OVERVIEW