Identification

24–28 cm; 106–194 g; wingspan 65–72 cm. The American Golden-Plover has large white patches on the sides of the breast. Females are somewhat whiter below and may have similar underpart patterns to the male Pacific Golden-Plover (Pluvialis fulva). Nonbreeding adults lack black on their underparts and breasts; their upperparts are extensively gray, especially around the head and neck. Juveniles lack the golden color and have heavily marked grayish underparts.

Several features have been proposed to distinguish conspecific species such as the Pacific Golden-Plover and the American Golden-Plover, but only three methods are consistently reliable: the number of primaries exposed beyond the longest tertial (2–3 for the Pacific Golden-Plover; 4–5 for the American Golden-Plover), the extent of primary projection past the tail-end (~0–9 mm for the Pacific Golden-Plover, 12–22 mm for the American Golden-Plover), and differences in breeding plumage. Tibia length (longer in the Pacific Golden-Plover) and bill shape (typically shorter and finer in the American Golden-Plover, but often longer and more bulbous in the Pacific Golden-Plover) can sometimes aid in differentiation (2 Golley, M. (2009). American & Pacific Golden Plovers in Norfolk – and a brief review of the identification criteria. Birding World. 22(7): 283–286. Close ). However, in some cases involving molting birds and those in nonbreeding plumage, definitive species identification can be challenging. Nonbreeding adults exhibit less yellow than Pacific Golden-Plover adults. They are generally grayer with paler flecks than closer related species like the European Golden-Plover (Pluvialis apricaria) and thePacific Golden-Plover. Particularly in breeding plumage, white flanks are usually absent and the vent is mostly black. Distinguishing features during the breeding season include a brownish-gray underwing and wing feathers being noticeably larger and longer than the tail.

The American Golden-Plover is a medium-sized plover closely resembling the Pacific Golden-Plover. Ranges of all standard measurements overlap between the two species (see 3 Johnson, O. W., and P. M. Johnson (2004). Morphometric features of Pacific and American Golden-Plovers with comments on field identification. Wader Study Group Bulletin 103:42–49. Close ; Appendix 1).

The following features are helpful for differentiating the species: the total length of the American Golden-Plover is 24–28 cm, which frequently exceeds the total length of the Pacific Golden-Plover (23–26 cm). The flattened wing of an American Golden-Plover is greater than 180 mm and is typically less than 175mm for the Pacific Golden-Plover. The American Golden-Plover tends to have a slightly shorter bill and tarsus, and less tibia exposure than the Pacific Golden-Plover, contributing to a shorter-legged appearance in the American Golden-Plover. Plumage distinctions are evident, with the Pacific Golden-Plover having bright yellow markings on dark grayish-brown underparts and the American Golden-Plover having similar but less colorful markings. The most reliable criteria for field identification of the two species (3 Johnson, O. W., and P. M. Johnson (2004). Morphometric features of Pacific and American Golden-Plovers with comments on field identification. Wader Study Group Bulletin 103:42–49. Close ) lie in their definitive alternate plumage during spring and part of the summer, along with the extension of primary feather tips beyond the longest tertials on the folded wing (typically 4–5 tips in the American Golden-Plover and 2–3 tips in the Pacific Golden-Plover, although beware of molting or growing tertials). Primary tip projection past the end of the tail is greater in the American Golden-Plover (about 12–22 mm) than in the Pacific Golden-Plover (around 0–9 mm). Individual variation often associated with molting during the non-breeding season and in transitional plumages while molting will make some individuals (including extralimital records) difficult to identify with certainty (4 Hayman, P., J. Marchant, and T. Prater (1986) Shorebirds: an identification guide to the waders of the world. Houghton Mifflin Company, Boston, Massachusetts, USA. Close , 5 Dunn, J. L., J. Morlan, and C. P. Wilds (1987). Field identification of forms of Lesser Golden-Plover. International Bird Identification: Proceedings of the 4th International Identification Meeting, Eilat, Israel. Close , 6 Marchant, S., and P. J. Higgins, Editors (1993). Handbook of Australian, New Zealand and Antarctic Birds. Volume 2. Raptors to Lapwings. Oxford University Press, Melbourne, Australia. Close , 7 Paulson, D. R. (1993). Shorebirds of the Pacific Northwest. University of Washington Press, Seattle, Washington, USA. Close , 8 Kaufman, K. (2000). Birds of North America. Houghton Mifflin, New York, NY, USA. Close , 3 Johnson, O. W., and P. M. Johnson (2004). Morphometric features of Pacific and American Golden-Plovers with comments on field identification. Wader Study Group Bulletin 103:42–49. Close ).

Males in definitive alternate plumage are generally easily distinguishable, with a white neck stripe on the American Golden-Plover that stops abruptly at the upper breast, while continuing past the breast forming a conspicuous wash along the sides and flanks on the Pacific Golden-Plover. However, females exhibit less distinct coloration, with variability in mottled appearance. Sexual dimorphism is typical for the Pacific Golden-Plover and for most American Golden-Plovers, though some American Golden-Plover females are less mottled, darker (brownish black), and nearly male-like in appearance.

Distinctive plumages in definitive basic, formative, and juvenile stages also help in species identification, with grayish coloration on the head, neck, breast, and upperparts of the American Golden-Plover and yellowish buff in the Pacific Golden-Plover. Subtle variations in non-breeding feathering can sometimes obscure species separation. Body mass is similar in both species but can vary greatly over the annual cycle, including instances of abnormally low mass, particularly in juveniles during stressful migration periods (9 Connors, P. G. (1983). Taxonomy, distribution, and evolution of golden plovers (Pluvialis dominica and Pluvialis fulva). Auk 100:607–620. Close , 5 Dunn, J. L., J. Morlan, and C. P. Wilds (1987). Field identification of forms of Lesser Golden-Plover. International Bird Identification: Proceedings of the 4th International Identification Meeting, Eilat, Israel. Close , 10 Golley, M., and A. Stoddart (1991). Identification of American and Pacific golden-plovers. Birding World 4:195–204. Close , 6 Marchant, S., and P. J. Higgins, Editors (1993). Handbook of Australian, New Zealand and Antarctic Birds. Volume 2. Raptors to Lapwings. Oxford University Press, Melbourne, Australia. Close , 7 Paulson, D. R. (1993). Shorebirds of the Pacific Northwest. University of Washington Press, Seattle, Washington, USA. Close , 11 Beaman, M., and S. Madge (1998). The Handbook of Bird Identification for Europe and the Western Palearctic. Princeton University Press, Princeton, NJ, USA. Close ). Age criteria are uncertain for first-year birds in spring because juveniles replace all primary wing feathers during Preformative Molt (contrary to the Pacific Golden-Plover, 12 Johnson, O. W., and P. M. Johnson (1983). Plumage-molt-age relationships in "over- summering" and migratory Lesser Golden-Plovers. Condor 85:406–419. Close , 13 Pyle, P. (2008). Identification Guide to North American Birds. Part II: Anatidae to Alcidae. Slate Creek Press, Point Reyes Station, CA, USA. Close ). Thus, the appearance of these feathers is identical to that of adults (14 Jukema, J., O. W. Johnson, J. Aldabe, and P. Rocca (2011). Wing and tail moult of American Golden-Plovers Pluvialis dominica on wintering grounds in Uruguay, with confirmation that juveniles replace all primaries during their first non-breeding season. Wader Study Group Bulletin 118:129–131. Close ). Wing lengths (though on average shorter in first-year birds) are also similar to those of adults (13 Pyle, P. (2008). Identification Guide to North American Birds. Part II: Anatidae to Alcidae. Slate Creek Press, Point Reyes Station, CA, USA. Close , 15 Jukema, J., J. B. Dunning Jr., P. Vlas, L. Brierley, and P. Brooks (2015). Morphological variation in spring migrant and wintering American Golden-Plovers Pluvialis dominica. Wader Study 122:128–134. Close ).

The American Golden-Plover is smaller than the European Golden-Plover (Pluvialis apricaria). Also, European Golden-Plover has mostly white wing-linings, whereas the underwing of American Golden-Plover is smoky gray. Black axillars, white wing stripe, and white rump and uppertail distinguish the Black-bellied Plover (Pluvialis squatarola) in all plumages from the three golden-plover species. Compared to the latter, alternate plumage of the Black-bellied Plover is particularly distinctive with silver-gray upperparts, a white undertail, and more extensive white on the head, neck, and sides of breast.