ML186766971

Age

Not specified

Sex

Not specified

Observation details

***Mega. 3rd record for Massachusetts, 1st for Barnstable County, and roughly the 10th record for the east coast of the United States. A few previous records in late July suggests some trace movement of adults through the eastern US in this window: 7/25/1989 in DE, 7/20/2013 in MA, 7/30/2019 in NC. Most other records, also adults, are from early September. Newfoundland alone has approximately 10 records, with no other records in eastern Canada. The first Massachusetts record was from 4/21/2002 at Plum Island (found by Rick Heil) and the second was on 7/20/2013 at Plymouth Beach, found by trip leaders and a few participants of a cancelled BBC pelagic. During an International Shorebird Survey, we visited the Powder Hole, which was filled with thousands of shorebirds (although roped off to visitors). As we made progress conducting the ISS, we arrived to a vantage point on the eastern side of the Powder Hole. Eventually I noticed a golden-plover in a mottled plumage state sitting on the flats, assuming that it would be an American. I immediately noticed the short primary extension relative to the tail length, and began trying to count the number of primaries extending beyond the tertials. Wind had been blowing the tertials such that they were rarely in a relaxed position, and so it was hard to accurately count the number of primaries extending beyond the tertials. At one point, I thought I was counting 4-5 (good for American), and other times I thought it was only 3 (good for Pacific). When relaxed, the tertials appeared quite long, nearly reaching the tail tip (good for Pacific). I did not think the bird seemed particularly long-legged, which is an oft-cited character of Pacific. At this point though, I had no idea what I was looking at, so I began taking photos. After about 15 minutes of observation, the bird flew off to the far opposite side of the Powder Hole. We did not pursue the bird further, partly because I was satisfied with the photos, and partly because we needed to begin the trek to the high tide roost 5-6 miles north on South Beach. We left the Powder Hole having recorded the bird as “golden-plover sp.," with the photos needing to be circulated to others for opinions. I sent the photos to several plover identification enthusiasts and field guide authors, such as Steve Howell, Alex Lees, Killian Mullarney, Michael O’Brien, Chris Batty, and Marshall Iliff. I am very thankful for their feedback. The consensus was that this was a typical Pacific Golden-Plover. Their full responses will be submitted to the Massachusetts Avian Records Committee. Field marks that they noted are summarized below: -Short primary extension, ending just barely beyond or at the tail tip -Longer and thicker bill than would be expected on an American -The outer primaries appear to be retained from juvenile plumage, which is typical of Pacific and indicates a 1st summer individual rather than molting out of alternate plumage -The golden-spotted scapulars contrasting with the gray coverts is typical of Pacific and less so of American -The white sides of the breast are narrow, whereas American should be thicker -The black barring on the sides and flanks are thinner and more widely spaced, whereas American should have broader bars, resulting in less white on the sides

Technical information

Model

Canon EOS 7D Mark II

Lens

EF400mm f/5.6L USM

ISO

800

Focal length

400 mm

Flash

Flash did not fire, auto

f-stop

f/5.6

Shutter speed

1/5000 sec

Dimensions

1089 pixels x 726 pixels

Original file size

548.33 KB