Justin,
May I be so bold as to suggest that there is an error in your recent note
suggesting an American Golden Plover? Firstly the overall greyish tone is
completely normal for Pacific Golden Plover at this time of year, most birds
will show the expected golden tones but at this time of year one should
expect a few to appear greyish to a degree not unlike a Grey Plover. Further
more the shorter primary projection would suggest PGP not AMP. I am not
suggesting that you definitely did not see AGP but thought it appropriate to
point out that a lot more information would be required before a conclusive
result could be reached.
Every year we receive reports of American Golden Plover during October &
November and to date none of them have proved to be AGP. In Australia this
is an especially tough call, many ornithologists consider this species pair
among the most difficult of wader identification challenges. It is fairly
well known that the plumage characteristics of fulva vary considerably, both
individually and with such factors as wear, fading and moult, and that
overlap is possible in many of the plumage characters useful in
identification, including some often considered diagnostic for dominica. In
particular, many fulva can show a markedly grey appearance (lacking any buff
tones) coupled with bold whitish supercilia, a strongly-capped and seemingly
rather long-winged attenuated appearance in addition to other more subtle
characters often considered as indicative of dominica. However, much depends
on age, wear, moult and an accurate assessment of these aspects. To
adequately accept an American Golden Plover beyond all reasonable doubt will
therefore require that all characters important in identification be
carefully and fully documented. Furthermore, one also needs to consider such
factors as age and the effects of plumage wear, fading and moult when
arriving at an identification. Key features relevant to the identification
of birds in juvenile and non-breeding plumage include:
Are all the tertials present? (on each wing there should be three obvious
ones staggered in length plus a less obvious relatively short forth one
partly visible beneath the longest one).
The ratio of primary projection compared with the length of the longest
tertial.
The number of primary tips-visible beyond the longest tertial and beyond the
tip of the tail and their relative spacing.
The position of the tip of the longest tertial relative to the tip of the
tail.
The strength and extent of any buff tones and golden or buff spangling
anywhere on the bird.
In flight views, the presence and extent of any foot-projection beyond the
tip of the tail.
The flight call and any other calls.
Any differences in overall size and structure; note, these are rather
subtle, subjective and difficult to appreciate and are of only minor
importance compared with the above characters.
Good birding
Tony
Birding-Aus is on the Web at
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