Posted by Phil Pickering (208.46.229.85) on January 08, 2002 at 21:59:25:
The head appears white, so this is apparently a very young bird, presumably first or second "stage", whatever that means.
Based on info in Harrison and some quick photo study, it appears that the combination of white head, and the large, wide-based dark wedges extending down onto the body from the leading half+ of the underwing, forming a broken, but nearly complete breast band, and enclosing a sort of diamond-shaped white area on the belly, is prototypical of first-stage Magnificent, and less typical, if not atypical of other species or ages.
Perhaps this pattern is diagnostic for Magnificent, I'm not sure.
In photos, it appears that the color on the breast of the "tawny-breasted" form of Great should typically be quite appreciable in the field, and form a complete, clearly-deliniated unbroken breast band, but I don't know how variable this is. In any case, my guess is that the apparent brownish-buff wash on the breast of this bird could very well be an artifact of the lighting, particularly given the sun angle. I sort of see the same tinge on the belly.
I wasn't able to find any photos of "white-breasted" Greats at first try, but the drawings in Harrison suggest that first and second stage birds typically don't show such large dark wedge shapes on the sides of the breast, and lack the diamond-ish shape to the white on the belly.
If the bill is gray with a yellow tip as it appears, that would also apparently be much better for young Magnificent. In photos, it seems that young Greats more typically have monocolor bills.
Assuming the breast could be tinged by the lighting, I don't see anything clearly wrong with Magnificent, based on limited knowledge and a few minutes of research. Will have to spend more time reading up on this problem.
Cheers,
Phil