ML116050311

Age and sex

Juvenile, Unknown sex - X

Media notes

Field marks supporting the identification of the photographed individual as an American Golden-Plover are: - Four primaires visible beyond the longest tertial. The tertials are very short, ending approximately halfway to the tail tip (contra outer third on PAGP) and well short of the tip of p7; whereas even on PAGPs with long primary projection, the longest tertial still typically ends very close the tip of p7. By late Sep, juvenal tertials should be fully grown and the noted projection is symmetric on both sides. - The legs (tibia in particular) look relatively short in all photos. The bird is actively feeding and sleek, which should accentuate the leg length (i.e., not resting and "fluffed up"). Bill proportions also appear better for AMGP, compared to, on average, the longer, heavier, and less-tapered bill of PAGP. - Dense coarse markings on breast, extending through the belly are suggestive of AMGP, contra yellow washed breast and sparsely marked whitish belly on juvenile PAGP. Features that have been mentioned as suggestive of PAGP include: - Brightness and relatively extensive yellow wash in the face, including in front of eye and malar. However, I place emphasis on structural features over coloration. The brightness of upper parts is certainly matched by other photos of AMGP in Macaulay Library such as: https://macaulaylibrary.org/asset/180830321. - Primary extension past the tail appears less than half the bill length. However, this too is matched by other photos of AMGP (e.g., https://macaulaylibrary.org/asset/266920501). While there is intra-specific variation and inter-specific overlap in many of the cited features, overall, in my opinion, the weight of evidence favours AMGP.

Observation details

Field marks supporting the identification of the photographed individual as an American Golden-Plover are: - Four primaires visible beyond the longest tertial. The tertials are very short, ending approximately halfway to the tail tip (contra outer third on PAGP) and well short of the tip of p7; whereas even on PAGPs with long primary projection, the longest tertial still typically ends very close the tip of p7. By late Sep, juvenal tertials should be fully grown and the noted projection is symmetric on both sides. - The legs (tibia in particular) look relatively short in all photos. The bird is actively feeding and sleek, which should accentuate the leg length (i.e., not resting and "fluffed up"). Bill proportions also appear better for AMGP, compared to, on average, the longer, heavier, and less-tapered bill of PAGP. - Dense coarse markings on breast, extending through the belly are suggestive of AMGP, contra yellow washed breast and sparsely marked whitish belly on juvenile PAGP. Features that have been mentioned as suggestive of PAGP include: - Brightness and relatively extensive yellow wash in the face, including in front of eye and malar. However, I place emphasis on structural features over coloration. The brightness of upper parts is certainly matched by other photos of AMGP in Macaulay Library such as: https://macaulaylibrary.org/asset/180830321. - Primary extension past the tail appears less than half the bill length. However, this too is matched by other photos of AMGP (e.g., https://macaulaylibrary.org/asset/266920501). While there is intra-specific variation and inter-specific overlap in many of the cited features, overall, in my opinion, the weight of evidence favours AMGP.

Technical information

Model

Canon EOS 7D Mark II

Lens

EF500mm f/4L IS II USM

ISO

640

Focal length

500 mm

Flash

Flash did not fire, auto

f-stop

f/4.0

Shutter speed

1/4000 sec

Dimensions

1024 pixels x 683 pixels

Original file size

466.64 KB