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Great Knot id

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  • n_lethaby
    All: After hearing some were questioning the id of this bird, I took a look at Matt S s much better photos and compared them against my collection of Japanese
    Message 1 of 3 , Aug 29, 2009
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      All:

      After hearing some were questioning the id of this bird, I took a look at Matt S's much better photos and compared them against my collection of Japanese photo guides and also against the photos on www.orientalbirdimages.org

      I was probably able to look at something like 70 birds. My conclusions were:

      1. The bird's bill is clearly too short for a Great Knot. This was also my impression from personal experience of a few thousand or more of this species.

      2. The bird also looks rather short-legged.

      3. I don't think the pale at the base of the bill is a problem for the bird being a Great Knot. I found quite a number of photos showing a paler greenish tone to the base of the lower mandible.

      4. Although there were insufficient bird photos from late summer to fully evaluate the feature, in general there was a average difference between the underpart patterns of this bird and most Great Knots. The Great Knot photos I looked at generally showed birds with more solid dark triangles on the underparts and more narrow dark points and streaks. The SD bird shows a much hihger proportion of wide dark 'V's, that is more typical of Surfbird. It should be stressed that Great Knots certainly show wide dark 'V's too, but these form a lower proportion of the dark markings on the underside.

      Without finding more photographs of adults in worn-breeding plumage, it's hard to do a lot more analysis. However, I didn't see anything else that seemed a major strike against a Great Knot. However, Surfbirds are similar enough in many respects that it might be hard to find differences from a hybird.

      Nick Lethaby
      nlethaby@...
    • Joseph Morlan
      ... For additional comparison, I photographed a small flock of molting adult Great Knots in mid-August 2005 at Cairns, Australia. The photo is at:
      Message 2 of 3 , Sep 1, 2009
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        On Sat, 29 Aug 2009 23:36:11 -0000, "n_lethaby" <nlethaby@...> wrote:

        >Without finding more photographs of adults in worn-breeding plumage, it's hard to do a lot more analysis. However, I didn't see anything else that seemed a major strike against a Great Knot. However, Surfbirds are similar enough in many respects that it might be hard to find differences from a hybird.

        For additional comparison, I photographed a small flock of molting adult
        Great Knots in mid-August 2005 at Cairns, Australia.

        The photo is at:

        http://outdoors.webshots.com/photo/2704377490040004820FFvnaj

        Full size:

        http://image48.webshots.com/48/3/77/49/2704377490040004820FFvnaj_ph.jpg

        Also I checked the text of the following book and can find no mention of
        hybrids between the Surfbird and any other species:

        McCarthy, E. 2006. Handbook of Avian Hybrids of the World. Oxford Univ.
        Press.

        --
        Joseph Morlan, Pacifica, CA jmorlan (at) ccsf.edu
        SF Birding Classes start Sept. 15 http://fog.ccsf.edu/~jmorlan/
        California Bird Records Committee http://www.californiabirds.org/
        Western Field Ornithologists http://www.westernfieldornithologists.org/
      • Lethaby, Nick
        Joe: I would be wary about using pictures from Australia in mid-August since these might be first summer birds that spend the whole austral winter there rather
        Message 3 of 3 , Sep 1, 2009
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          Joe:

          I would be wary about using pictures from Australia in mid-August since these might be first summer birds that spend the whole austral winter there rather than birds that had come back from Siberia. Is there anyone in Cairns who could comment on this? I would be pretty surprised if migrant Great Knots from Siberia make it back to Aus by mid-August. They generally don't get to Korea or Japan until late July/early August.

          Obviously none of the birds here are as heavily marked as the SD bird, but if they are first-summers it wouldn't be a fair comparison.

          Nick

          -----Original Message-----
          From: Joseph Morlan [mailto:jmorlan@...]
          Sent: Tuesday, September 01, 2009 11:24 AM
          To: Lethaby, Nick
          Cc: CALBIRDS@yahoogroups.com; SDBIRDS@yahoogroups.com
          Subject: Re: [CALBIRDS] Great Knot id

          On Sat, 29 Aug 2009 23:36:11 -0000, "n_lethaby" <nlethaby@...> wrote:

          >Without finding more photographs of adults in worn-breeding plumage, it's hard to do a lot more analysis. However, I didn't see anything else that seemed a major strike against a Great Knot. However, Surfbirds are similar enough in many respects that it might be hard to find differences from a hybird.

          For additional comparison, I photographed a small flock of molting adult
          Great Knots in mid-August 2005 at Cairns, Australia.

          The photo is at:

          http://outdoors.webshots.com/photo/2704377490040004820FFvnaj

          Full size:

          http://image48.webshots.com/48/3/77/49/2704377490040004820FFvnaj_ph.jpg

          Also I checked the text of the following book and can find no mention of
          hybrids between the Surfbird and any other species:

          McCarthy, E. 2006. Handbook of Avian Hybrids of the World. Oxford Univ.
          Press.

          --
          Joseph Morlan, Pacifica, CA jmorlan (at) ccsf.edu
          SF Birding Classes start Sept. 15 http://fog.ccsf.edu/~jmorlan/
          California Bird Records Committee http://www.californiabirds.org/
          Western Field Ornithologists http://www.westernfieldornithologists.org/
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