Re: [BIRDWG01] Golden-Plover Sp., South Carolina, USA, 7/4/09
To All:
I have been away from my computer for a few days and missed this discussion, but I was happy to read the comments of others before I added my opinion. One thing I want to point out is the variable plumage condition of adult AGPLs, with some birds showing a mottled condition to their breeding plumage in June on the breeding grounds (see this adult female AGPl photographed on the North Slope of Alaska in mid-June http://www.kevinkarlsonphotography.com/gallery/v/Shorebirds/Plovers/American+Golden+Plover_+br+female_+AK_+June.jpg.html. Some might suggest that this bird is already in partial body molt, but I have seen numbers of female AGPLs during my four years as a biologist on the North Slope that appeared similar to this bird in early June, which suggests that some individuals only show this mottled appearance. Adult males do not show this incomplete plumage. I have also noted that adults start to show feather wear and some partial body molt on the tundra by late June prior to migrating south.
Doug Pratt's points on the configuration of the white pattern on the sides of the upper breast for AGPL are supported by the previous photo as well, and this plumage condition matches the South Carolina bird. I am not so sure that this bird is in active molt at all, but only showing typical wear of a mottled adult female in early July. AGPLs do not replace all their wing coverts prior to migration, but retain variable numbers of nonbreeding feathers depending upon energy levels during migration. Note the scattered nonbreeding feathers on this adult male photographed in Alaska on the breeding grounds in early June http://www.kevinkarlsonphotography.com/gallery/v/Shorebirds/Plovers/AGPL+m_+br_+nest+distraction_+AK_+July.jpg.html. Even some nonbreeding scapulars are retained on this adult male, which typically show a more complete plumage condition than females. The South Carolina bird does not show any appreciable molt in my opinion, and since AGPLs begin their molt on the breeding grounds and suspend active molt during migration, this bird conforms to what I would expect from a worn adult female AGPL. I agree with Peter Pyle in that it is difficult to age AGPLs in spring due to the winter molt pattern of both adults and juveniles, so I would be hesitant to call this bird an early second calendar year bird.
I think the overall shape, especially the small pigeon-like head, are consistent with AGPL, unlike the juvenile bird in Quebec, which unfortunately went down as a bright AGPL (Why did we not get to see the 7 comments only posted privately to Laval Roy that suggested AGPL instead of PGPL)? The bill appears slightly long for AGPL, but it is thin and not as robust as PGPL typically shows. This feature is a good supportive feature for these two similar species, but not one to base a solid ID on. Another point in support of AGPL is the reduced gold and white feather edges and notches on the back at this early summer date. PGPL should show much bolder and larger gold edges and notches, which give the back a brighter overall gold appearance compared to AGPL. The body structure is also more bottom heavy, which is better for AGPL, and not as chest-heavy as PGPL, which oftne results in a more horizontal posture for AGPL when relaxed at rest. However, as pointed out by Lee Evans, it is very difficult to judge body posture from only one or two photos.
I think it is safe to say that this is a typical female AGPL in early July, which is not terribly outside the migratory range for this species. A failed breeder from Churchil could conceivably start migrating a few weeks earlier than other adult birds. I photographed this worn AGPL in Cape May NJ in mid-August a few years ago http://www.kevinkarlsonphotography.com/gallery/v/Shorebirds/Plovers/American+Golden+Plover_+molting+adult_+NJ_+Aug.jpg.html, although this one suggests an early second calendar year bird that has a good mixture of breeding and fairly fresh nonbreeding feathers.
kevin karlson
------ Original Message -----
From: "Ken Blankenship" <kenhblankenship@...>
To: BIRDWG01@...
Sent: Thursday, October 22, 2009 11:56:06 AM GMT -05:00 US/Canada Eastern
Subject: [BIRDWG01] Golden-Plover Sp., South Carolina, USA, 7/4/09
The photograph below was submitted without comment to the Carolina Bird
Club webmaster Kent Fiala, who posted it to their website at this link:
http://www.carolinabirdclub.org/gallery/amgp_giduz.html
Thankfully, the records compiler for the Carolinas (Josh Southern) was
gleaning from the photo gallery and came across it; it was never posted on
any ListServ nor was there any discussion that I am aware of. The
assumption was that it is an AMERICAN GOLDEN-PLOVER, as this is the
expected species in our region. However, the date is quite exceptional in
my opinion: 4 July 2009.
I am far from a shorebird expert, and not at all experienced with Pacific
Golden-Plover. Still, I just feel that the date alone merits this bird
being considered by experts just to make sure a much rarer species was not
overlooked. Though I would imagine an AGPL is much more likely - a failed
breeder, a bird who did not successfully bulk up and never completed
migration, etc... I would simply appreciate some feedback to make sure.
Thank you,
Ken Blankenship
Editor, "From the Field" (Georgia Ornithological Society)
Southern Atlantic Regional Editor, "North American Birds" (American Birding
Association)
http://www.wingsoverga.com
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