In connection with the appearance of an interesting Myiarchus
flycatcher in urban Santa Cruz, central California, in January 2003, I
was among those asked to come observe the bird and assess whether it was
a Dusky-capped Flycatcher M. tuberculifer or something else. Steve
Gerow, the first observer asked for this opinion (i.e., the bird had been
tentatively reported as a Dusky-capped), noted a number of critical problems
with that proposed identification. At that point David Suddjian, Dan Singer,
Joe Morlan, Robbie Fischer, Rita Carratello and I were invited to visit
the private residence to help in an identification. As more fully described
elsewhere
on this web site, and on Joe
Morlan's web page, we collectively identified the bird as a Nutting's
Flycatcher M. nuttingi. The bird was viewed thereafter by hundreds
of observers, and was featured in the local Santa Cruz newspaper. It was
present 1-18 Jan 2003 and then disappeared for a week, but reappeared in
late January and is still present at this posting (5 Feb 2003). The web
pages cited above, prepared the day of our initial identification, emphasized
separation points between Nutting's and Dusky-capped Flycatcher but gave
rather short shrift to the possibility of Ash-throated Flycatcher M.
cinerascens. Separation between Nutting's and Ash-throated was long
considered difficult to impossible in the field (e.g., Dickerman &
Phillips 1953), and it was until 1961 that a full analysis showing that
two species were involved was published (Lanyon 1961). However, recent
field experience by many birders with wintering birds at Patagonia Lake
State Park, Arizona (14 Dec 1997-21 Mar 1998) and at Mason Regional Park,
Orange Co., California (11 Nov 2000-26 Mar 2001) has led to some "conventional
wisdom" about identification, and some of it now appears in newer field
guides (e.g., National Geographic 1999). These birds were much discussed,
especially the Arizona bird. Important comments by Will Russell (who found
the Arizona bird in 1997), Kimball Garrett, Chris Benesh, and Michael O'Brien
are in the archives
of the Frontiers of Bird Identification chatline. A stunning color
photo by Larry Sansone of the Arizona bird appears on the cover of Field
Notes, Vol. 52, No. 2 (1998; see also below) and more color photos
are inside (photos by Paul Buckley, commentary by Kenn Kaufman). A color
photo of the southern California bird by Brian E. Small is on the cover
of Western Birds, Vol. 32, No. 1 (2001).
In my initial discussion, some ten characters were mentioned that were thought important. Now, after a detailed review of the literature (more below), it is apparent that some are important and others are not. Before delving into a variety of characters, though, I want to draw attention to what I called "the classic wing-panel" pattern with its 'yellow 'mid-panel' feature." To the far right is a wonderful Ed Harper photo of the Patagonia Lake bird taken in Jan 1998, and a smaller inset on which I show the three elements of the wing panel:
Thus, to summarize, in broad simple terms and subject to all the caveats
below, wing patterns of Nutting's and Ash-throated Flycatchers can be classified
into three basic types:
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These patterns can be useful to help properly age a bird in the field.
As we shall see, knowing the exact age/plumage may be critical for identification.
It is important to recognize a juvenal-plumaged bird, and to exclude the
presence of juvenal feathers (or properly understand them) on a mid-winter
Myiarchus. The bird on the far right is a juvenal Ash-throated Flycatcher,
taken in southern California on 4 Sep 1981 (© John Marchant). Note
that it not only has a "red-red-white" pattern to the wings, but that it
still possesses juvenal rectrices (all rufous with a thin brown stripe
down the shaft of the feather).
Pyle (1997) explains that molt in hatch-year Myiarchus begins on the nesting ground, is suspended during migration, and is usually completed on the wintering ground (there are a small percentage, ~5% of Ash-throats, that do not complete all covert/secondary replacement until the second basic molt). The entire tail (except, occasionally, the central rectrices) is replaced on the summer grounds, but often secondary molt is suspended until the winter grounds are reached. The outermost 1-4 secondaries are often (but not always) replaced before migration, leaving inner secondaries, next to the tertials, as unreplaced juvenal feathers. It is apparent to me, in reading details of some Ash-throated Flycatchers that are vagrants to eastern North America during fall migration (e.g., October into December; see Murphy 1982), and from review of some photos of eastern vagrants, that many juvenal secondaries have yet to be replaced even though the tail feathers have been replaced. Lanyon (1961) describes Ash-throats with up to 4 secondaries still retained in late November and this is on the winter grounds! It seems logical that many fall vagrants to the East undergoing substantial migratory movement in the wrong direction never begin secondary molt until the ultimate winter grounds are reached. More study is needed, but this hypothesis would explain Ash-throats in the East whose wing pattern might be described as "red-red-white," just like this September juvenal bird. |
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SOME CAVEATS ABOUT COLOR PERCEPTION IN PHOTOS AND
ON THE WEB:
Some colors reproduce well in photos and on the web, and others do not. People also differ in perception; there has long been problems in reaching consensus as to where a gull's legs, for example, might fall within a yellow to pink continuum. With reference to the Myiarchus problem, there are problems with "pale yellow" vs. "white" and problems with "gray" vs "brown." As to the first problem, I use as an illustration the yellow vent strap present on the wintering Black-throated Green Warbler at Laguna Grande at the same time as the Myiarchus in Santa Cruz, and seen by dozens of observers. The lovely top photo (right) is by Bill Hill [more on his web site]. Bill took this shot on Provia FX professional film with his huge lens and a Fresnel flash. Although the pale yellow vent strap is subtle, I find it obvious to see. In contrast, my own more distant photo (below right) of the same bird, taken with Sensia 400 film and without flash, puts the underparts in shadow even on a sunny day, and the vent strap all but disappears. There is a PhotoShop tool that can help with colors, if properly used. On the top photo, the magenta arrows point at well-lit spots on the flanks and in the vent strap. Using the color picker, I could then "pour" the color the computer said in found at those spots into the numbered boxes I created to the right. The flank color is bright white. The subtle color in the vent strap area is not white. It is hard to describe the color perhaps pale straw? but it is in the "pale yellow" family of colors, as opposed to "white." On the bottom photo, the color picker shows the head color, nicely lit, as bright yellow. But the belly in the shade which I see as white because we know it is white, and also because we can compensate for shadow in real life to "see" the unshaded color, is picked as a rather medium gray by the color picker [box #2 in the lower right corner]. Dan Singer has drawn my attention to a good online color chart. It will be helpful as a reference in this project. |
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Using the color picker correctly may help some in evaluating photos (and I thank Bill Hill for the idea in the first place!). It is also important to recognize that color differences between photos of the same bird will occur, and that some will be accounted for by differences in lens, film, and use of flash. In general, the professional films preferred by high-end photographers will give a more saturated color than the grainier, faster films used by "record shot" takers like myself. I also see substantial variation in color saturation and hue in digital shots, and some of this is accounted for by differences in the scopes used for the "digiscoping." Some scopes are "cool" toward blue on the color spectrum, while others are warmer more toward red on the spectrum. Additional differences in both film and digital photography will be the result of lighting conditions at the time. Given these facts, I find it rather amazing that some folks who look at web photos can claim with apparent confidence that the color on, say, the edges of the secondaries were "white", as opposed to "pale yellow" or "lemon yellow" (a term that implies paleness to me, but not to everyone). A bit more on that later....
SOME OTHER KEY EXPLANATIONS ABOUT THESE PAGES and the
PHOTOS:
I was able to collect photos from a variety of photographers, and have
been doing so for years while creating a teaching and reference collection.
I am thus very grateful to Tom Grey, Ed Harper, Greg Lasley, Kevin McKereghan,
J. Van Remsen, and Larry Sansone for the use of their work. Unless otherwise
indicated, all photos shown on these pages are unedited for color, contrast,
brightness, density, and hue. Most, however, have been "sharpened" slightly
for web presentation. This PhotoShop tool is standard practice; indeed,
new versions have a "web reproduction" automatic feature that does what
I routinely do on all web photos do a slight "sharpen unsharp mask" and
make slight adjustments at both ends of the brightness/contrast scale.
I have not used any of those automatic features but have sharpened the
"mask" (i.e., the entire photo) or just portions of it. Sharpening has
no effect on color presentation at all. But it does correct the inevitable
loss of sharpness in the scanning process, restoring the photo to a near
original pristine condition.
Where I have adjusted anything that affects color, that will be explained. On this page, for example, I have lightened the scan of the cover of Field Notes magazine, as the scan itself came out very dark. Everything else on this page is otherwise unretouched.
THE PURPOSE AND LAYOUT OF THESE PAGES:
In the pages linked here, I look in detail at various topics about
Nutting's Flycatcher identification in an attempt to place before you information
on the identification of the Santa Cruz Myiarchus. The technique
used is, after consulting the literature, to compare photographs of known
identity birds with the Santa Cruz individual. For these purposes, I accept
the 1997-1998 Arizona bird as a Nutting's Flycatcher, as well as the 2000-2001
Orange Co., California, bird. One obvious problem with this comparison
is that both the Nutting's Flycatchers used for comparative purposes, and
the Santa Cruz bird, are birds in January. All are reasonably fresh-plumaged
individuals. Except for the juvenal Ash-throated Flycatcher shown above
on this page (a September bird in fresh juvenal plumage), all the Ash-throated
Flycatcher photos were taken between April and early June, and are thus
somewhat more worn individuals. I have tried to take this element of bias
into account, but it is there.
Mostly I aim at putting evidence out there for you to consider, and for you to draw your own conclusions. My own conclusion will be on a final linked page. These pages are:
The best part about preparing a web discussion is that one learns a whole lot of stuff you didn't know before. In trying to come to grips with this subject, I have consulted all of the literature listed below. I have also reviewed chat line archives on the Arizona and southern California birds, and have discussed these problems at length with Joe Morlan, Dan Singer, Steve Gerow, Rita Carratello, and David Suddjian. I have also reviewed published comments by a wide variety of observers, including, but not limited to, Chris Benesh, Kimball Garrett, Kenn Kaufman, Alvaro Jaramillo, Michael O'Brien, Will Russell, and Joel Weintraub, plus unpublished thoughts from others, and benefited from them all.
I am particularly grateful to the photographers who published important shots, and/or supplied unpublished photographs for review, including Richard Bowers, Jr., Paul A. Buckley, Rita Carratello, Cindy Cummings, Tom Grey, W. Ed Harper, Greg W. Lasley, Peter LaTourrette, Dan Lockshaw (of Owling.com), Kevin McKereghan, Joe Morlan, J. Van Remsen, Jr., Larry Sansone, John Sorensen, and Joel Weintraub.
LITERATURE CITED: