From south-bay-birds-bounces+south-bay-birds-archive=[[email protected]] Mon Sep 22 06:58:37 2003 Received: from www.plaidworks.com (localhost [127.0.0.1]) by plaidworks.com (8.12.9/8.12.9) with ESMTP id h8MDt7IB022782 for <[[email protected]]>; Mon, 22 Sep 2003 06:55:07 -0700 (PDT) Received: from smtp9.Stanford.EDU (smtp9.stanford.edu [171.67.16.36]) by plaidworks.com (8.12.9/8.12.9) with ESMTP id h8MDsGZP022741 for <[[email protected]]>; Mon, 22 Sep 2003 06:54:16 -0700 (PDT) Received: from lawmail1.stanford.edu (lawmail1.Stanford.EDU [171.64.212.80]) by smtp9.Stanford.EDU (8.12.10/8.12.10) with ESMTP id h8MDsAn2015340; Mon, 22 Sep 2003 06:54:10 -0700 (PDT) In-Reply-To: <[[email protected]]> Subject: Re: [SBB] Golden Plover To: [[email protected]] X-Mailer: Lotus Notes Release 6.0 September 26, 2002 Message-ID: <[[email protected]]> From: "Tom Grey" <[[email protected]]> Date: Mon, 22 Sep 2003 06:55:46 -0700 X-MIMETrack: Serialize by Router on lawmail1/stanford(Release 5.0.12 |February 13, 2003) at 09/22/2003 06:55:48 AM MIME-Version: 1.0 Content-type: text/plain; charset=us-ascii Cc: X-BeenThere: [[email protected]] X-Mailman-Version: 2.1.2+ Precedence: list List-Id: South Bay Birding List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: south-bay-birds-bounces+south-bay-birds-archive=[[email protected]] Errors-To: south-bay-birds-bounces+south-bay-birds-archive=[[email protected]] As the title of my original post indicated, I had doubts about the i.d. of the GOLDEN PLOVER near the track intersection in New Chicago Marsh. This was after looking at my pictures and reading in Paulson and Hayman et al. But, hey, I'm no expert! I'm interested to see from Alvaro's post that some doubt may be warranted. I've uploaded two additional photos, 3 and 5, that show further features to 2 and 4, the ones already posted. One thing - the bird is definitely an adult. As Bill Bousman pointed out in his initial post on this bird, there are still a few black feathers from the breeding plumage on the underparts. These are barely visible in my photos. On the yellow or gold appearing in the upperparts, it was 7.30 am, so has the warming effect of early morning light, and my scope/camera combo tends toward the warm side. However my very blurry photo of the bird preening, 3 below, seems to shows even more yellow or gold. Paulson writes of adult nonbreeding plumage that "the most brightly marked AMERICAN show yellow fringed mantle feathers and black-dotted scapulars and tertials, while the most brightly marked PACIFIC have yellow dots on the mantle and yellow notches or fringes on the tertials." Notice the yellow-fringed tertials on this bird. On wingtip extension past the tailtip, the distinguishing feature most emphasized by Paulson, my other pictures of the bird in profile are consistent with photo 2. Paulson says Pacific is either equal or with primaries a little past tail. American show an extension "at least equal to the distance from eye to base of bill," and this bird looks to just hit that minimum. Hayman et al describe American and Pacific as BOTH having wingtips well past tailtip, distinguishing them from Eurasian, which has them about equal. On primary extension (past the tertials) -- I have posted another picture, 5, with a different angle, bearing on this feature. Paulson says that on Pacific it should be just longer than the bill length, shorter in American. As Alvaro says, in this molting bird the tertials aren't exactly neatly aligned, so the feature is a little hard to pin down, but 5 seems to show a borderline length of extension. http://www.geocities.com/tgrey41/GoldenPlover2.jpg http://www.geocities.com/tgrey41/GoldenPlover3.jpg http://www.geocities.com/tgrey41/GoldenPlover4.jpg http://www.geocities.com/tgrey41/GoldenPlover5.jpg Tom Grey [[email protected]] http://www.geocities.com/tgrey41/index.html Alvaro Jaramillo , et> [[email protected]] cc: 09/21/2003 09:18 Subject: Re: [SBB] Golden Plover PM At 12:18 PM 9/21/2003 -0700, Tom Grey wrote: >This morning, the GOLDEN PLOVER in New Chicago Marsh was on the same island >near the track intersection reported yesterday by Kris Olson. Here are a >couple of digiscoped pictures. The primary tips go well beyond the tail in >2, cutting in favor of AMERICAN. On the other hand, there seemed to be >fringing of the scapular and mantle feathers that looked pretty close to >yellow, see esp 4, which may cast some doubt. > >http://www.geocities.com/tgrey41/GoldenPlover2.jpg >http://www.geocities.com/tgrey41/GoldenPlover4.jpg This is a challenging bird in my opinion. Is this the bird that is being identified as the American Golden Plover?? I think that this may actually be a Pacific Golden Plover. First of all, it is important to figure out its age, while there are some real fresh feathers and no worn (breeding) feathers I think this is an adult. First of all the primaries in the photos look brownish and thus worn, rather than fresh as expected on a juvenile. Juveniles will have all feathers fresh and of an even age, they will not show moult at this time of year. The scapulars have rather reduced golden markings, the coverts look all messed up (not lined up in neat rows) suggesting that they are moulting, and the neck lacks a speckled, streaky look - all of these features point to an adult rather than a juvenile. So if it is an adult, the extensive amount of golden on the upperparts pretty well eliminates American Golden Plover which is much more grey-brown above as a non-breeding (basic plumage) adult. I would also expect an adult American Golden to be less well advanced in terms of body moult, as that species has a generally later moult timing due to the long migration distance it undergoes, as compared to the Pacific which tends to have a much shorter migration distance. I am unsure what to think of the primary projection (primaries past tertials). Photo 4, seems to show a moderate primary projection rather than a long one. Photo 2 appears to show a long primary extension, but I wonder if this is partially an illusion. It is difficult to see if this is the case in the photo, but looking at the original, or a higher resolution scan may do the trick. In any case, I throw out the idea that this may be a Pacific Golden Plover out for discussion. cheers Al Alvaro Jaramillo Biologist San Francisco Bay Bird Observatory P.O. Box 247 Alviso, CA 95002 (408)-946-6548 http://www.sfbbo.org/ [[email protected]] ***** NOTE NEW E-MAIL ADDRESS**** _______________________________________________ Do not post admin requests to the list. They will be ignored. south-bay-birds mailing list ([[email protected]]) Help/Unsubscribe/Update your Subscription: http://www.plaidworks.com/mailman/options/south-bay-birds/south-bay-birds-archive%40plaidworks.com This email sent to [[email protected]]