McGILL BIRD OBSERVATORY

PHOTO LIBRARY

Ruby-crowned Kinglet / Roitelet à couronne rubis (Regulus calendula)


 Introductory notes:
Males are readily recognized when showing their ruby crown, but it is often concealed, and easiest to confirm when in the hand.  Ageing cues on the wing tend to be subtle and difficult to identify reliably; the tail is somewhat more distinct for many individuals, but again there are many intermediates, therefore skulling is recommended in fall, and in spring many are best classed as AHY unless wing and tail both provide distinct indications of age.


QUICK TIPS:
1) Check the crown - females generally lack a ruby crown, while males have a ruby crown patch, but note that it may be well concealed; some AHY/ASY females may have a few ruby-tipped feathers.

2) Check the shape of the outer rectrices - on HY/SY birds they are narrow and pointed, while on AHY/ASY birds they tend to be more broad and rounded; however, there are many intermediates that are difficult to classify

3) Compare the median and greater coverts - on some HY/SY birds a molt limit can be seen between the fresher/darker median coverts and older/duller greater coverts, while on AHY/ASY birds they are uniform in appearance (but beware they often appear uniform on HY/SY individuals too).

4) Look at the primary coverts - on many HY/SY birds they are narrow and pointed (with minimal green edging by spring), while on AHY/ASY birds they tend to be more broad and rounded (with distinct green edging retained through spring).

Species account updated January 2011

Ageing and sexing guidelines:

January - July:

AHY - M
Ruby crown (though often concealed); uniform wing with greenish edging on broad and rounded primary coverts; broad and rounded tail.
AHY - F
Lacking red in the crown; uniform wing with greenish edging on broad and rounded primary coverts; broad and rounded tail.
HY - M
Ruby crown (though often concealed); primary coverts somewhat narrow/pointed; relatively narrow and tapered tail.
HY - F
Lacking red in the crown; primary coverts somewhat narrow/pointed; relatively narrow and tapered tail.

-

July - December:

AHY - M
Ruby crown (though often concealed); uniform wing; broad and rounded primary coverts; broad and rounded tail.
AHY - F
Lacking red in the crown; uniform wing; broad and rounded primary coverts; broad and rounded tail.
HY - M
Ruby crown (though often concealed); may have molt limits among median and greater coverts; primary coverts somewhat narrow/pointed; relatively narrow and tapered tail.
HY - F
Lacking red in the crown; may have molt limits among median and greater coverts; primary coverts somewhat narrow/pointed; relatively narrow and tapered tail.
 

Ageing and sexing details:

JAN - JUL:  after-second-year male

Males are easily distinguished from females by having a large ruby-red crown, but beware that in a relaxed state the crown can be largely to entirely concealed by surrounding olive head feathers.


An ASY male with its ruby crown feathers nicely exposed.
Photo by Marcel Gahbauer, McGill Bird Observatory (QC), April 2006


A more typical view, with only a hint of red visible in the crown when relaxed.
Photo by Marie-Anne Hudson, McGill Bird Observatory (QC), May 2008


ASY kinglets lack molt limits on the wing and feathers tend to average somewhat broader and with more greenish edging than on SY birds, but note that the distinctions are subtle and often insufficient to determine age. 


A typical ASY wing, showing fairly broad primary coverts with green edging.
Photo by Marie-Anne Hudson, McGill Bird Observatory (QC), April 2008


A close-up of the coverts, highlighting the green edging on the broad, rounded primary coverts.
Photo by Marcel Gahbauer, McGill Bird Observatory (QC), April 2006


ASY kinglets tend to have rectrices that are more broad and rounded than those of SY birds, but there is a fair amount of variability and by spring the tail may be somewhat worn and difficult to assess reliably. If the wing characteristics are also unclear, such an individual should be considered AHY.


Although not an extreme case, the outer rectrices are sufficiently broad and rounded at
the tip to suggest that these are likely basic rather than juvenile feathers, and that this
is therefore likely an ASY bird on the basis of the tail.

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

RETURN TO AGE/SEX OVERVIEW

JAN - JUL:  after-second-year female

Females have olive crowns, but may sometimes have 1-2 red or orange-red feathers in the centre of the crown. 


A typical ASY female, showing no red on the crown.
Photo by Marie-Anne Hudson, McGill Bird Observatory (QC), April 2009


Another ASY female.
Photo by Marie-Anne Hudson, McGill Bird Observatory (QC), May 2008


ASY kinglets lack molt limits on the wing and feathers tend to average somewhat broader and with more greenish edging than on SY birds, but note that the distinctions are subtle and often insufficient to determine age.


A somewhat worn looking wing, especially at the tips of the primaries and greater coverts,
but still with greenish edging to the primary coverts (and a correspondingly adult tail).

Photo by Simon Duval, McGill Bird Observatory (QC), May 2010


A more distinctly ASY wing, with noticeably broad primary coverts and distinctly
round-ended primaries.

Photo by Marie-Anne Hudson, McGill Bird Observatory (QC), April 2009


ASY kinglets tend to have rectrices that are more broad and rounded than those of SY birds, but there is a fair amount of variability and by spring the tail may be somewhat worn and difficult to assess reliably.  If the wing characteristics are also unclear, such an individual should be considered AHY.


A distinctly ASY tail, with broad and fairly round-tipped rectrices.
Photo by Marie-Anne Hudson, McGill Bird Observatory (QC), April 2009


A somewhat more worn tail, a bit later in spring than the previous example, but note
that the outer rectrices are still fairly broad, even if not as rounded at the tip.

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

RETURN TO AGE/SEX OVERVIEW

JAN - JUL:  second-year male

As with ASY Ruby-crowned Kinglets, SY males are easily distinguished from females by their ruby crown when it is visible, but it may be largely to entirely concealed much of the time.  In most cases, ageing requires careful examination of both the wing and tail. 


A side view with only a bit of colour visible in the crown.
Photo by Marcel Gahbauer, McGill Bird Observatory (QC), May 2006


A top view of a different SY male, with more colour visible; note that occasionally some
of the central crown feathers may be yellow or orange instead of red.

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


Although molt limits typically occur on SY kinglets between the median and greater coverts, or sometimes among the inner greater coverts, these are generally indistinct and difficult to recognize with certainty.  However, the wing overall tends to be somewhat duller than on ASY kinglets, on average shows somewhat more wear, and has less green edging, especially on the primary coverts and secondaries.


A fairly typical SY wing, dull and fairly worn overall, with relatively narrow and pointed
primary coverts largely lacking greenish edging.

Photo by Manon Dubé, Banff National Park (AB), June 2007


A slightly greener wing overall, but still with minimal edging on the feathers.
Photo by Manon Dubé, Banff National Park (AB), June 2007


An extremely worn wing, shortly before the prebasic molt.
Photo by Manon Dubé, Banff National Park (AB), June 2007


SY kinglets generally retain their juvenile rectrices, which on average are narrower and more pointed than the basic feathers of ASY kinglets, and also tend to be somewhat more worn by spring.


A typical SY kinglet tail, with the outer rectrices quite tapered and worn at the tips.
Photo by Manon Dubé, Banff National Park (AB), June 2007


An even more worn and faded example.
Photo by Manon Dubé, Banff National Park (AB), June 2007

RETURN TO AGE/SEX OVERVIEW

JAN - JUL:  second-year female

SY females have olive crowns without red or red-orange feathers. As with males, a good view of the wing and tail is usually required to determine age, and even then there may be many intermediates that are more safely aged as AHY, especially late in spring.


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


As with SY males, SY females typically have molt limits between the median and greater coverts, or sometimes among the inner greater coverts, but these are usually indistinct and difficult to recognize with certainty.  However, the wing overall tends to be somewhat duller than on ASY females, on average shows somewhat more wear, and has less green edging, especially on the primary coverts and secondaries.


A rather "good-looking" wing for a SY kinglet, but note the narrow and pointed outer
primary coverts, with limited greenish edging.

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


SY kinglets generally retain their juvenile rectrices, which on average are narrowre and more pointed than the basic feathers of ASY kinglets, and also tend to be somewhat more worn by spring.


A typical SY kinglet tail, with narrow and pointed rectrices.
Photo by Marie-Anne Hudson, McGill Bird Observatory (QC), May 2008

RETURN TO AGE/SEX OVERVIEW

JUL - DEC:  after-hatch-year male

AHY males are easily distinguished from AHY females when their large ruby-red crown is visible, but beware that it can be mostly to entirely concealed.  Ageing requires a good view of the wing and tail, or checking for skull pneumatization (until early October). 


An AHY male showing a bit of its ruby crown.
Photo by Marcel Gahbauer, McGill Bird Observatory (QC), September 2005


A more typical view of a male, with the ruby crown not at all visible from this angle.
Photo by Marcel Gahbauer, McGill Bird Observatory (QC), October 2009


ASY kinglets have a uniformly fresh wing, with broad primary coverts featuring distinct greenish edging.


A typical AHY wing, dark and fresh, with distinct greenish edging on the primary coverts.
Photo by Marcel Gahbauer, McGill Bird Observatory (QC), October 2009


Another example also showing broad primary coverts with green edging, but note the
overall paler appearance of the wing, influenced by the lighting of the photo.

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


A close-up showing the broad and rounded primary coverts with distinct green edging.
Photo by Marcel Gahbauer, McGill Bird Observatory (QC), September 2005


AHY kinglets typically have broad and rounded rectrices; those that do are readily aged by this feature, but note that there are many intermediates that require confirmation by wing or skull. 


A typical AHY tail, with broad and relatively rounded outer rectrices.
Photo by Marie-Anne Hudson, McGill Bird Observatory (QC), October 2007


A relatively uncommon variant, with rectrices that are as broad as usual for an AHY
kinglet, but taper to a distinct point at the tip.

Photo by Marcel Gahbauer, McGill Bird Observatory (QC), October 2009

RETURN TO AGE/SEX OVERVIEW

JUL - DEC:  after-hatch-year female

Females have olive crowns, but may sometimes have 1-2 red or red-orange crown feathers. As with males, ageing requires a good view of the wing and tail, or checking for skull pneumatization (until early October).


A typical AHY female.
Photo by Marcel Gahbauer, McGill Bird Observatory (QC), October 2004


In late summer or early fall, AHY kinglets undergoing molt have a much scruffier appearance.
Photo by Seabrooke Leckie, McGill Bird Observatory (QC), August 2006


AHY kinglets have a uniformly fresh wing, with broad primary coverts featuring distinct greenish edging.


A typical AHY kinglet wing, dark and fresh, with broad and rounded primary
coverts showing distinct greenish edging, also present on the secondaries.

Photo by Marcel Gahbauer, McGill Bird Observatory (QC), October 2010


The same individual as in the previous section, photographed while undergoing its
prebasic molt, with a number of pin feathers visible in this photo. Note that the colour
and contrast is accentuated by this photo being taken in bright sunlight.

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


AHY kinglets typically have broad and rounded rectrices; those that do are readily aged by this feature, but note that there are many intermediates that require confirmation by wing or skull.


An extreme example, with very broad and blunt-tipped rectrices.
Photo by Marcel Gahbauer, McGill Bird Observatory (QC), October 2010


A more typical example, broad, but not quite as blunt at the tip.
Photo by Marie-Anne Hudson, McGill Bird Observatory (QC), September 2005


Another example, a bit pointed at the tip, but still more broad and rounded than
would be expected on a typical HY kinglet (still, worth checking wing and/or skull
to confirm individuals like this with a less than extremely distinct adult tail).

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


This photo corresponds to the AHY bird in molt in previous sections; note that it appears
substantially narrower and more worn; although the bleaching is accentuated by the
sunlight, it is distinctly browner than the fresh feathers typically seen in fall.

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

RETURN TO AGE/SEX OVERVIEW

 

JUL - DEC:  hatch-year male

As with AHY males, the sex of HY males can be determined easily if their ruby crown is visible, but it is often largely to entirely concealed.  Again, ageing usually requires a good look at the wing and tail, though until pneumatization completes (as early as the beginning of October), the most reliable confirmation for HY birds is the presence of an incomplete skull.


A HY male showing a hint of red in the crown.
Photo by Marcel Gahbauer, McGill Bird Observatory (QC), October 2010


A more typical view, with no red visible.
Photo by Marcel Gahbauer, McGill Bird Observatory (QC), September 2005


Molt limits in HY kinglets typically occur between the median coverts and greater coverts, or sometimes among the inner greater coverts.  Sometimes these are apparent when the replaced feathers are fresh, but more often the distinction is too subtle to be reliable.  Juvenile primary coverts on HY kinglets are on average somewhat narrower and more pointed than the basic feathers of AHY birds, but beware that this distinction can be more difficult to see in fall when feathers are fresh; similarly, by spring the minimal green edging to the juvenile primary coverts has often worn off, helping distinguish them from basic feathers, but when fresh in fall they may look quite similar.  Therefore since most HY wings in fall are only subtly different from AHY wings, tail is the best plumage feature to use in most cases, and skull development should be checked in most cases.


A relatively dark and fresh HY wing.  Although exagerated a bit by the shadow from the
finger holding the wing, there is a molt limit between the darker replaced median coverts
and the duller retained greater coverts. Note also that while the primary coverts have a bit
of green edging, they are not particularly broad.

Photo by Marcel Gahbauer, McGill Bird Observatory (QC), October 2010


Another example showing a contrast between the median and greater coverts; again the
primary coverts have green edging, but note that they are relatively narrow and pointed.

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


HY kinglets retain juvenile rectrices that are typically narrower and more pointed than those of AHY kinglets.  This is often the most reliable plumage clue for ageing, but beware that a fair proportion of kinglets have tails with an intermediate shape, and should be aged only if skull development provides a definitive answer.


A relatively typical HY tail, with fairly narrow and pointed outer rectrices.
Photo by Marcel Gahbauer, McGill Bird Observatory (QC), October 2010


Another example, with some feathers slightly broader, but with a more pointed shape.
Photo by Marcel Gahbauer, McGill Bird Observatory (QC), September 2005

RETURN TO AGE/SEX OVERVIEW

JUL - DEC:  hatch-year female

As with AHY females, HY females have olive crowns without ruby feathers, but bear in mind that many males appear identical when their ruby crown feathers are concealed. 


Photo by Marcel Gahbauer, McGill Bird Observatory (QC), October 2009


As with males, molt limits in female HY kinglets typically occur between the median coverts and greater coverts, or sometimes among the inner greater coverts. Sometimes these are apparent when the replaced feathers are fresh, but more often the distinction is too subtle to be reliable. Juvenile primary coverts on HY kinglets are on average somewhat narrower and more pointed than the basic feathers of AHY birds, but beware that this distinction can be more difficult to see in fall when feathers are fresh; similarly, by spring the minimal green edging to the juvenile primary coverts has often worn off, helping distinguish them from basic feathers, but when fresh in fall they may look quite similar. Therefore since most HY wings in fall are only subtly different from AHY wings, tail is the best plumage feature to use in most cases, and skull development should be checked in most cases.


This example illustrates the lack of any obvious molt limits on the wing, but note
the narrow and pointed shape of the primary coverts.

Photo by Marcel Gahbauer, McGill Bird Observatory (QC), October 2009


HY kinglets retain juvenile rectrices that are typically narrower and more pointed than those of AHY kinglets. This is often the most reliable plumage clue for ageing, but beware that a fair proportion of kinglets have tails with an intermediate shape, and should be aged only if skull development provides a definitive answer.


A particularly extreme example, with very narrow and pointed outer rectrices.
Photo by Marcel Gahbauer, McGill Bird Observatory (QC), October 2009

RETURN TO AGE/SEX OVERVIEW 

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