American Golden-Plover (Pluvialis dominica)
Evaluation of recent Golden-Plover images taken in
Arizona and notes on identification.
Andrew Core (
Michael C. Moore (firstname.lastname@example.org)
Golden-Plover (Pluvialis dominica) is a
casual spring and fall transient in Arizona. There
are more records in fall and these are generally from
late August through mid-November, with most records in
September and October. Most fall records are of
juveniles. This species presents an ID challenge
because it is very similar to Pacific
Golden-Plover (Pluvialis fulva). These two forms are so similar
that they were only recognized as separate species in
1993. Pacific Golden-Plover has only been recorded once in Arizona
(6-12 August 1998). American Golden-Plovers are
generally absent from the continental US in winter, but
a few Pacifics winter in California.
In many shorebirds, juvenile and nonbreeding adult
plumages are very distinctive from each other, but this
is not the case in golden-plovers in which juvenile and
adult nonbreeding plumage are only subtly different.
usually be distinguished from adults by their crisp plumage,
neatly spangled upperparts and neatly mottled breast.
Juvenile Pacific and American Golden-Plover can usually be distinguished
from each other by noting (1) the projection of the primaries and tertials
relative to the tail, (2) the pattern and color of the face
and breast, and (3) the
size of the head and bill (Paulson 2005; O'Brien et
al. 2006). Pacific Golden-Plover
also has slightly longer legs, which allow for the toes
to project slightly past the tail in
flight, and a different call.
Two different juvenile American Golden-Plovers were
seen in Arizona in fall 2008 and both were photographed.
In this paper, we analyze the photographs of these
individuals to illustrate the key field marks that
separate them from Pacific Golden-Plover.
Fig. 1. This American Golden-Plover was
discovered by Peter Walsh on 25 September 2008 and
photographed by Andrew Core on 26 September 2008 at
Whitewater Draw in Cochise County. Note relative position of the ends
of the tertials, tail and primaries. The short
tertials and long primaries relative to the tail are a
good mark for American Golden-Plover.
26 September 2008, photo by Andrew Core
Analysis of bird in Fig 1.
Primary Projection: American
Golden-Plovers have long primaries that always
project well past the tail. Pacific
Golden-Plovers have shorter primaries that are
usually even with the tail or project only slightly
past it. In this bird, the primaries project well beyond
tail. Although in Pacific the wings may project some, a search of images on the
web did not reveal any instances of this much projection in a Pacific. This
field mark indicates American Golden-Plover and is one of the best overall field
marks to separate these species.
Number of primaries visible: In
fresh plumage, most Pacific Golden-Plovers have 2-3
primaries visible past the tertials and most
Americans have 4-5. Primaries 9 and 10 are
usually more closely spaced in Pacific, but there is
overlap in this character. In the field, this bird appeared to have three
primaries visible past the tertials, which is often cited as a mark for Pacific, and the pictures are not of sufficient detail to challenge this. However, "It is important to note that very close spacing of primary tips 9 and 10... may give the visual impression of a single feather when viewed in the field, and thus lead to an incorrect count." (see
Johnson and Johnson 2004).
Therefore, the number of primaries projecting past
the tertials in this bird could be three OR four. If
three, one is forced to conclude that the p9 and p10
are not closely spaced. Four would fit better with
the spacing. This field mark was not conclusive in
this case. In general, if 4-5 primaries are
visible, that indicates American. If three are visible, it seems
inconclusive, especially if P9 and P10 are not closely spaced as they should be,
in Pacific. It should be noted that the number
of primaries visible can be affected by wear of both
tertials and primaries and would appear quite
different in an actively molting bird.
Tertials: In American, the tertials are
usually close to the base of the tail, rarely
projecting more than half way down the tail.
In Pacific, the tertials are longer and usually
reach or nearly reach the end of the tail. In
this bird, the primaries are prominently exposed past the tertials
and the tertials do not come close to the tip of the tail. This fits quite well with
American, and not at all with Pacific.
Color: Juvenile American usually shows few
if any yellow tones in this plumage. Juvenile
Pacific is overall brighter with bright yellow often
on the face and breast. The overall bright
color was striking on this bird and while suggestive
of Pacific, it is not absolute indicative.
Examination of images found by searching on www.flickr.com
produced at least two pictures of American that
matched the Whitewater bird very well. The lack of
yellow on the face and breast of this bird is
especially suggestive of American, but the
literature suggests there is overlap in these
Other marks that fit American are the gray chest and the bright
supercillium above and behind the eye. The bright spangles and fresh looking plumage
indicate a juvenile. One strange mark is the color of the bill; this bird has a yellow bill with a dark base, and all books and pictures consulted show only a black bill.
Is it possible this bird was probing in yellow mud?
In conclusion, the evidence - particularly the primary extension past the tail and
length of the tertials
- points to this being a brightly colored juvenile American Golden-Plover.
Fig. 2. This bird was found and photographed by Allen and Denise Klaiber in the Santa Cruz Flats area, Pinal
County and was present from from 24-26 October 2008.
24 October 2008, photo by Allen and Denise Klaiber
Analysis of bird in Fig 2:
This juvenile bird shows the typical slim,
small-billed, dove-headed look of an American Golden
Plover. Pacific Golden-Plover is a bulkier bird and
usually has a longer, thicker bill. This bird has a
prominent white supercillium setting off the dark
cap which is typical of American. Pacific usually
has a plainer face, usually with a strong yellow
cast. Finally, as in Fig. 1, the primaries project
well past the tail whereas the tertials fall well
short of the tail, again a characteristic of
American Golden-Plover. The number of primary tips
is not visible in the photo.
We would like to thank Mark Stevenson, John Yerger, Gary Rosenberg,
Gavin Bieber and three anonymous reviewers for helpful comments.
Alderfer, J, ed. 2006. Complete Birds of
North America. National Geographic Society,
Johnson, O.W. and Johnson, P.M. 2004. Morphometric
features of Pacific and American Golden-Plovers with
comments on field identification. Wader Study Group
Bull. 103: 42–49.
O'Brien, M., Crossley, R, and Karlson, K. 2006.
The Shorebird Guide. Houghton Mifflin, New York.
Paulson, D. 2005. Shorebirds of North
America: The Photographic Guide. Princeton
University Press, Princeton.
Submitted 1 November
Accepted 26 December 2008