Posted by Phil Pickering (208.46.229.122) on October 08, 2001 at 10:38:20:
Forgive me, but there is more to say on the issue of bill shape, etc. Respectfully -
After some research, it is clear to me that the appearance of the nasal area on this bird is not necessarily unusual for Gray Flycatcher. GRFL have upper mandibles that are relatively flat, but certainly not perfectly flat - the slope of the bill sides continues above the nares, forming a narrow rounded ridge. This ridge (the culmen) is comparatively low, but it is easily high enough to create the reflective surface visible between the nares in the right hand additional photo. I took the liberty of enlarging this photo, and I cannot see anything obviously unusual for GRFL. As far as I can tell, the culmen is fairly evenly sloped and relatively low-ridged throughout its length. If some are seeing the appearance of a raised ridge or covering over the nares, I suspect it is likely due to a trick of reflection and shadow, particularly considering the angle to the light source which appears to be almost directly above the bird. In fact, I suspect that the higher culmen of a Phainopepla should cast a much more obvious shadow on the left side of the bill surface at this angle to the light. In any case, I strongly feel that the appearance of the nasal area is a minor point at best, because it is impossible to confidently judge at the low resolution of this photo. I'm also convinced that it is not possible to confidently determine whether the bill has a hook or not at this resolution.
The nares are in the proper position for a GRFL - and if they appear larger than normal it may be because there is wear to the feathering and bristles at the base of the upper mandible to which the nares normally abut, or perhaps which normally even partially conceal the nares. GRFL appear to have somewhat more prominent nares than other empids, anyway. Wear to the feathering at the bill base may also create the impression that the base is thicker than normal for a GRFL. The point has already been made that the profile of the bill from above is perfect for GRFL.
There is a remarkable and very helpful set of close up empidonax photos printed large enough to see fine bill detail in the Audubon Encyclopedia of N.A. Birds. Included in this book is a very interesting photo of a GRFL, in that some of the bird's belly feathers appear to be raised, ruffled, or worn - creating DARK spots on the belly even in what is apparently direct, even lighting. This raises the question of whether the body feathers of GRFL might not be pale-tipped with dark bases?? That would certainly help explain the appearance of the breast, throat, and sides of the neck on the mystery bird. The feathering in this area appears nearly whitish and paler than the back (right for GRFL) but quite worn and ruffled. If these feathers had darker bases, an extreme amount of wear could easily create the interspersed light/dark pattern that is clearly visible. Even if the bases to the body feathers are pale, this pattern could also easily be created by shadow effects due to uneven wear or molt. To me, the appearance of the feathering on the upper breast and surrounding area strongly suggests that the odd-colored appearance of the plumage on the entire bird is in the largest part due to extreme wear, perhaps abnormally extreme.
The GRFL in the photo in this book also displays a spectacle pattern nearly identical to the mystery bird's, and has a break in angle at the top of its very low forehead in the same place as the mystery bird. Additionally, in all of the GRFL photos I studied where the tertials were visible, the bird showed a very similar white patch to that in the tertials of the mystery bird. In most photos, the bird also happened to be captured in a similar posture to that displayed by the mystery bird (and typical of GRFL) - upright, hunch-backed, and with the tail held below a level plane with the body. In all 12 or so Phainopepla photos I was able to find the tail was held level with the body plane, the back was less hunched, and the posture was most often more forward (Phainopeplas may be able to drop their tails, but they do have a very long, thick ventral area that supports their longer tails that does not appear to be present on the mystery bird). These features, at the very least, are certainly not ambiguous to the point of being subject to individual judgement.
While the proportions of this bird are being judged by sight, their ratios (eye vs. head diameter, head diameter vs. body length, etc.) are very real marks - and are certainly measurable if it was necessary (I don't feel it is in this case). IMHO, when "jizz" is broken down to precisely defined individual characteristics it is not ambiguous.
I have rarely been able to speak with confidence about any of Joe's mystery birds, but I am absolutely confident that this is a large empidonax, almost certainly a Gray Flycatcher - that appears abnormally colored due to extreme plumage wear, photographic effects, or (likely) to a combination of both. It may also truly be genetically aberrant.
I'm done. On to the jaeger indeed.
Cheers,
Phil