January 22nd, 2006. East Providence, RI.
| Mew Gull Larus (canus) - form uncertain. (Adult winter).
| On Sunday, January 22nd, Dan
Finizia captured an excellent shot showing both the upperwing and the
underwing of the unidentified 'Mew' Gull. This shot
potentially reveals a few more useful clues as to the bird's identity.
To offer an interesting comparison, Clay Taylor has provided a great upperwing shot of a Mew Gull (brachyrynchus)
taken in California in mid-winter. I've added a few captions to copies of
each image to highlight some areas of interest in the wing patterns.
Comments to date (January 23rd):
The level of interest in this bird continues to be high and I've been
receiving some excellent feedback privately by email. Here's a few
excerpts from a few of these emails with particular reference to the
especially dark appearance of the upperparts of the Rhode Island bird in relation to Common Gull (Larus canus canus) in Europe;
From Ireland - "I
am quite sure I have never seen a Common Gull anywhere in Europe that
has had as dark upperparts as the Rhode Island bird, which I judge
to be a shade lighter than typical graellsii (Lesser Black-backed Gull), though of course this is difficult to determine accurately from on-web photos."
From Finland
(Opinion 1) - " My first impression is very similar to your opinion
(above): I don't think I see such birds in Finland. But let's see what
the others think. One problem is to interpret the exact tone in
photographs, but in this case this may be easier than usual because the
exposure and circumstances look very good, and there is a possibility
to a direct comparison."
From Finland (Opinion 2) - " Personally, I do not remember seeing ever a Common Gull with upperparts tone even near to that of graellsii Lesser Black-backed Gull.
I also noted the primary pattern of the American (Rhode Island) bird:
it seems like at least four (maybe 5) outer primaries are all-black
(except the mirror). I think this feature is not shared by Common Gulls
seen in Finland. Finnish birds have in 1-2 outermost primaries black to
the base and from third primary onwards bases of the primaries are grey
(whitish in under-wing), thus NOT creating similar black triangle to
the wing as shown by the American bird.
From Finland
(Opinion 3) - " In Finland, during winter we see some slightly darker
Common Gulls. But they are not very dark, surely lighter than graellsii and not very obvious even in flocks. In addition, they are quite scarce, and I am far from sure to claim that they are heinei and most of the birds in winter flocks are canus. Status of heinei
in Finland is not as well known as in southern Sweden, northern Germany
or Netherlands. Of course it has to occur, but we don't know how large
numbers.
To my eyes, the bird photographed by James Smith is either
brachyrhynchus or kamtschatschensis.
Bill without subterminal black, and type of head streaking are strange
for Common Gulls from this part of world. There is more black on wing
tip than typical brachyrhynchus, but I don't know whether it is enough to exclude that form (this is surely for north American birdwatchers to study).
I'm
especially grateful to all of the above who spent thier time reviewing
the images and offering thier opinions. In addition, I'm equally
grateful to Dan Finizia and Clay Taylor for offering the use of thier
images featured below.
More updates will follow in due course.
| Images appear courtesy of Dan Finizia and Clay Taylor
| | Page 1 of 2 (Go straight to Page 2) |
|
