Proposal (666) to South American Classification Committee

 

Add Pluvialis fulva (Pacific Golden Plover) to main list

A single Pluvialis fulva was photographed at Puerto Villamil, Isla Isabela, Galápagos, Ecuador, by Roger Ahlman (Freile et al. 2013; see below) on 16 February 2008.

 

Even though the published photograph is not very sharp, two additional photos and a detailed description of the bird were submitted to the Comite Ecuatoriano de Registros Ornitologicos, and it received unanimous votes for acceptance. Mantle and foreparts of the photographed bird (an immature) are warm buffy washed golden. This, coupled with tail projection, is diagnostic for P. fulva because P. dominica is greyer overall and slightly longer tailed.

There are additional sightings in mainland Ecuador and Galapagos (Ridgely & Greenfield 2001, Wiedenfeld 2006), as well as in other South American countries, but this is the first documented record.

Ref:

Freile, J. F., R. Ahlman, D. M. Brinkuizen, P. J. Greenfield, A. Solano-Ugalde, L. Navarrete & R. S. Ridgely. 2013. Rare birds in Ecuador: first annual report of the Committee of Ecuadorian Records in Ornithology (CERO). Avances en Ciencias e Ingenierías 5(2): B24-B41.

Ridgely, R. S. & P. J. Greenfield. 2001. Birds of Ecuador. Cornell Univ. Press, Ithaca, NY.

Wiedenfeld, D. A. 2006. Aves, the Galapagos Islands. Check List 2: 1–27.

 

Juan Freile, February 2014

 

 

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Comments from Jaramillo: “YES – Although I am a bit hesitant. I must admit that the Ecuadorian Committee reports are frustrating in that they lack details or analysis for difficult to identify species.  The photos as published are small and not easy to evaluate, particularly of this plover.  The identification of Pacific vs. American golden plovers can be straight forward in some cases, vexing in others, and one has to keep in mind that rarely the two species hybridize.  I am assuming that the other photos mentioned at least allowed evaluation of wing length and primaries past tertials.  In the proposal the note on American having a longer tail is incorrect.  The issue to note is the longer primaries, and number of primaries past the tertials in American vs. Pacific; the tail is pretty much inconsequential.  I am ok with the photo as it is a rather golden looking individual, and the legs are very long (good for Pacific).  But it would be great if birds like this could be published with some level of analysis or at least a series of photos that absolutely secure the identification.  I am going a bit on trust here as that single photo does not exclude a hybrid, and only marginally a Greater Golden Plover, as it does look slimmer than that species, but again that is marginal.”

 

Comments from Stotz: “NO.  If I got this as a rare bird committee member, I couldn’t vote Yes.  The photo is suggestive, but seems by itself inadequate to establish this ID for a first continental record.   Essentially, voting YES on this is accepting the decision of the Ecuadorian committee, not making an independent decision based on the information available to us.”

 

Comments from Zimmer: “NO.  I agree with Doug that the photo is not inconsistent with the identification, but that it is insufficient to establish this as a first continental record.  Specifically, the bird appears proportionately long-legged and relatively golden in plumage, both of which are good for fulva and poor for dominica.  However, plumage differences between the two species in anything other than definitive alternate plumage are best described as “tendencies” rather than “diagnostically different”.  Alvaro is spot-on in pointing out that the critical structural marks are the longer primaries and number of primary tips that are visible past the tertials in the folded wing.  Unfortunately, neither of these critical characters can be evaluated from the single photo attached to this proposal.  Alvaro is also correct in pointed out that contra statements in the proposal, tail length is of little or no value in separating the two species, even in the hand.”

 

Comments from Stiles: “NO. I agree with Doug – we don’t have all the evidence.  The ‘g’ on the photo (which I would call non-diagnostic; at the least, out of focus) implies that there are at least six more photos, which presumably might show some of the supposed diagnostic features that distinguish P. fulva from its congeners.  As it stands, this species seems appropriately placed on the hypothetical list.”

 

Comments solicited from Jon Dunn: “Can't do much with the one photo.  I wouldn't even lean towards Pacific.

 

“Characters I think are best in separating these two are:

 

“1.  Primary projection past tertials.  Much longer in American, but beware of molting birds and February would perhaps be a time when that feature is unreliable.

2.  Bill size and shape.  American seems to have a consistently smaller and more slender bill.  

3.  Contact call.  Quite different between the two species.

 

“Most Pacifics are quite bright, whereas Americans are dull.  Some Pacifics are dull, some juvenile Americans brighter.  Always use structure (number of exposed primaries and relative length past tertials).

 

“From the one photo I have, the bird doesn't look very bright to me.  The bill is perhaps thicker-based than most Americans, but really given the distance involved, I just can't tell.

 

“Bottom line is of course, not acceptable as a Pacific, based on the evidence I have before me.”

 

Comments from Remsen: “NO, based on Jon Dunn’s assessment.”

 

New photographs from Juan Freile: “I only sent what we published in the first annual report of CERO committee. Attached is all supporting material (two additional photographs + the record form). The record form provides additional details on the observation, as well as a description of what the observer considered key ID features. Space constraints and editorial decisions obliged us to publish a single photograph and not comparative descriptions in the species accounts.  We will take this into account for future controversial cases.”

 

 

 

 

 

 

Additional comments from Jon Dunn: “OK, I'll change my opinion.  The new photos from Juan are certainly more informative than the single one I reviewed before.  This bird is really bright.  More over the gold spots above look really large.  Some juvenile American Golden-Plovers are bright above but the spots are smaller, and by mid-winter they would look dull.  An additional feature worth looking at is the face pattern.  Pacific tends to have a postocular spot whereas American has dark auriculars.  We (with C.P. Wilds and Joseph Morlan) published this in a note in a special Israeli publication some 32 years ago.  I have a copy of that publication somewhere.  I'm not sure if the character is diagnostic, but it is certainly indicative.  The face pattern I see on the Ecuador bird fits Pacific in my opinion.  As for other jizzy features proposed by Jaramillo, I always uneasy about those, but don't disagree with his analysis.  I'll stick to the firmer things that catch my eye.  I presume that if I were on the SACC I would now be supporting the record, but I haven't yet read the written details, which say might include something about call [no notes on voice in the report -JVR].”

 

Additional comments from Zimmer: “I wanted to change my NO vote on the Pacific Golden-Plover from Ecuador to a YES vote.  In my original vote, which was based upon a single photograph, I offered that the photo was not inconsistent with an identification of fulva, and that the overall brightness of the bird, and, particularly, what I could see of the shape (long legs, short primary projection) suggested fulva rather than dominica.  But, I also felt that the single photo did not adequately show any of those characters well enough to accept what would be a first continental record.  However, with the addition of two more photos, the second of which shows the structural characters much better, I believe there is now enough photographic evidence to be certain that this was, indeed, a Pacific Golden.”