American Golden Plover in Australia?

Subject: American Golden Plover in Australia?
Date: 24 Nov 97 14:12:13 +1100
Identification of Pacific and American Golden Plover

There have been several reports recently of 'interesting' (i.e. pale-plumaged
and/or long-winged) Golden Plovers Pluvialis fulva/dominica from around the
Sydney region and North Queensland.  Two Golden Plovers at Pitt Town Lagoon
(Eastern end), Sydney, are apparently without any buff or golden colouration
and have exceptionally long primary projections.  A similar bird was sighted
at Long Reef, Sydney on at least two occasions last week and there are now
further reports from North Queensland.

All such birds should be studied very closely as there is a remote chance that
one or more of them could be an American Golden Plover P.dominica rather than
the regularly occurring Pacific GP P. fulva.  Yankee GP's are notoriously
difficult to separate from Pacific Golden Plovers , particularly at this time
of year when many JUVENILE Pacifics are in worn and faded plumage.  Such birds
are the main identification pitfall (although moulting adults can also present
problems; see below). Worn and faded juveniles typically look MUCH paler and
GREYER than a fresh-plumaged juvenile withn it's rich golden-buff tones. This
is because the golden-buff spots of the upperparts rapidly wear and (more
particularly) FADE to a much paler buff or even whitish colour thus markedly
reducing any buff tones, sometimes to the point where one has to look very
very closely indeed in order to pick out any pale buffish spots amidst the
upperparts feathering. This wear/fading phenomenon applies to the plumage as a
whole (save for the protected underwing) and increases the contrast between
light and dark areas as well. For example, the buff supercilium of fresh
plumage becomes strikingly white and appears more prominent and contrasting
against the dark crown and ear-covert spot; and buff tones elsewhere on the
face and neck are much reduced or absent, increasing the greyness and contrast
of the head/neck pattern generally. The blackish feather centres of the
mantle, back and scapulars tend to appear as a more solid blackish 'saddle',
giving a dark-backed appearance that contrasts strongly with the paler coverts
of the folded wing.  Loss of buff tones on the underbody often results in the
dark overlying streaks of the foreneck and breast showing as a marked pectoral
band contrasting with the (now) whitish lower breast and belly.

A classic example of a worn and faded juvenile fulva (just beginning moult to
first basic/winter plumage, with upper i.e. shortest two tertials missing
through moult!) is shown on p.81 of The Shorebirds of Australia (Pringle,
D.1987. Nat. Photo Index of Aust. Wildlife.). Note on this bird (photo'd Heron
I., Qld in November) the very grey overall appearance lacking any conspicuous
buff tones; the rather contrasting whitish supercilium against dark crown and
well-marked dark spot on ear-coverts; and the well-streaked pectoral band
contrasting against whitish belly.  Also note the rather long primary
projection, with two (closely-spaced) primary tips extending clearly beyond
the tail-tip; and compare the length of the exposed primaries beyond the tip
of the longest tertial - clearly less than half the length of that tertial
from it's base to it's tip. In comparison, a juvenile American GP would show a
noticeably longer primary projection, with 4-5 tips clearly visible beyond the
tip of the longest tertial; and the ratio of primary projection to length of
longest tertial would be about equal. In summary, the exposed primaries of
Pacific GP are only about quarter to half the length of the overlying tertials
(cf. equal on American GP) and only about 2-3 primary-tips are visible beyond
the tip of the longest tertial (cf. 4, sometimes 5 on American).  When making
these assessments it is important to (A) establish that you are looking at the
longest tertial and that none are missing through moult; (B) that all such
judgements are made from a perfectly side-on view (through a scope!) to remove
any effects of foreshortening. It is also crucial to age your bird as this is
vital to the identification process with this tricky species pair. Finally, it
is essential that direct comparisons be made with any other Golden Plovers
alongside your 'interesting' bird; and that field notes and sketches
(especially of the rear-end structure) be made on the spot.

As mentioned above, most tricky birds seen in October-December are worn and
faded juveniles but returning adults in early stages of moult to adult
non-breeding (basic/winter) plumage have also caused problems in the past.
Typically, such birds are losing a lot of their rich buff, black and white
summer plumage yet often retain most of or all of the bold white supercilium
of summer plumage in their otherwise moulting heads. This striking supercilium
in a basically colourless head often attracts the attention of the unwary
observer not fully familiar with the effects of moult, wear etc. For such
birds, close attention to the rear-end structure is vital and much care should
be taken to ensure that no tertials are missing through moult; otherwise, a
false reading of the rear-end structure will ensue!

Remember that to correctly identify these birds may take considerable effort
and time and good scope views are essential.  The structure of the rear end is
crucial in the identification process and one of the toughest tasks is waiting
for the bird to position itself so that it is possible to accurately determine
where the primaries and tertials fall relative to each other and the tail-tip.
Often the tail is not clearly visible. Basically a very thorough description
is required and even then not all birds can be positively identified.
Individual variation is such that there is almost complete overlap.  Ageing
the bird is important and photographs are of enormous benefit as documentation
when claiming an American Golden Plover here in Australia.  Remember that to
date there is only one confirmed record for Australia, that  being a (worn and
faded) juvenile bird seen and photographed at Byron Bay, NSW 8th November 1994
(BARC Case No.189). Detailed field notes and the photos were invaluable in
confirming the identification of that individual.

For those that are interested here is a list of just some of the important
features that should be looked for:

(1) The number of primary tips visible beyond the longest tertial.
(2) The ratio of the primary projection compared with the length of the
longest tertial.
(3) Are all the tertials present? (on each folded wing there should be three
obvious ones staggered in length plus a less obvious and markedly shorter
forth one at the base of the tertials).
(4) The position of the longest tertial tip compared to the tail.
(5) The extent of buff, golden or black markings anywhere on the bird.
(6) In flight views, the presence or absence of feet projecting beyond the tip
of the tail.
(7) Any differences in structure; note, these are rather subtle, subjective
and difficult to appreciate and are of only minor importance compared with the
above characters.
(8) The call.

Anyone interested in studying up on this tricky ID problem would be well
advised to seek out some of the more recent major ID papers on the subject or,
at the very least, delve into the Field ID and Plumages sections of HANZAB vol
2 (it contains a full summary of all these points, given from an A'asian
perspective). The following Literature may be useful:

Alstrom, P. British Birds 83: 70-2
Chandler, R.J.1989. North Atlantic Shorebirds. London and Basingstoke.
Hayman, P., et al 1986 Shorebirds. Croom Helm, London
Lewington I, Alstrom P, Colston P., 1991 A field guide to Rare Birds of
Britain and Europe, Harper Collins.
Rosair D, Cottridge D., 1995 Photographic Guide to Waders of the World, Hamlyn
Golley, M & Stoddart, A. 1991 Identification of American and Pacific Golden
Plovers. Birding World: 4: 195-204
Stoddard, A. 1989. Pacific Golden Plover in Norfolk. Birding World 2: 244-247
Gantlett, S & Millington R. 1995 The Pacific Golden Plover at Cley,
Norfolk.  Birding world:  :438-439
HANZAB Vol 2 (note: the ONLY ID info written from an Australian/southern
hemisphere perspective).

A joint message from
David Eades  
Tony Palliser 

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