photo by Chris
GentesThayer's Gull
Feb 17-25, 2004. Burt's Pit Road, Northampton, MA
photo by Chris
Gentes
Photos of Northampton Gulls of Feb 2004 including Thayer's by Mark Faherty
http://www.people.umass.edu/mfaherty/noho_gulls.html
Massbird Posts and other reports
FEB 17 - Tuesday
NORTHAMPTON (report from Larry Therrien) At the Burts Pit Rd compost area, a
large group of gulls (rough guess 500). The usual suspects plus 7 Iceland Gulls
including one 2nd year, six 1st year one of which had some dark coloration.
NOTE: Gull was seen by Andy Magee on this date as well.
FEB 18 - Wednesday
FEB 19 - Thursday
NORTHAMPTON (reported on Massbird by Hector Galbraith PhD) Today at the Northampton
compost station I had 6 Iceland Gulls (1 adult and 5 immatures) - this
may be an undercount since the birds were not behaving themselves and constantly
flying up and swirling about. I also had a 1st winter Glaucous Gull and
a bird that I am fairly sure was a 1st winter Thayer's
Gull. When I first saw this latter bird it was on the ground with
a 1st winter Iceland and a bunch of mixed age Herrings and Great Black-backs.
Its overall body color was a sort of cafe au lait - much paler than the Herrings
that were milling around but somewhat darker than the Icelands. What was noticeable,
however was its primaries (extending way beyond the tail) which were a darker
shade than the body (more cafe than lait!), but way less dark than a Herring's.
They contrasted somewhat with the mantle, back, and wing coverts. So far as
I could see the tertials were a solid beige and not notched. Its bill was a
solid black and its legs dull pink and its head shape was rounded and Iceland-like.
The bird then flew up and over my head and I could see that its generally pail
tail had a broad beige-colored subterminal band with an inconspicuous paler
terminal band. In flight from below it looked almost as pale as the Iceland
juveniles and had the same translucent look to the primaries and secondaries.
My guess is that this bird might be a 1st winter Thayer's Gull. However, these
birds are notoriously difficult to separate from darker Icelands and also from
pale Herrings. Also, I did not get a long enough look to be entirely confident
in my ID. However, if anyone is visiting these gulls over the next day or so
it would be worth watching out for.
FEB 20 - Friday
NORTHAMPTON (reported on Massbird by Mark Faherty) God only knows how many white-winged
gulls are in Northampton right now. Based on three hours careful accounting
of ages and individuals, I can say with certainty that there were a minimum
of 10 Iceland Gulls at the compost piles on Burt's Pit Rd. Also there
was a 3rd winter Lesser Black-backed Gull and the possible Thayer's,
which was easy to pick out when it was around. A 1st winter Glaucous
was down river of the Coolidge Bridge, as previously reported. I digiscoped
some blurry shots of the Thayer-esque gull (possibly the same one reported by
Hector Galbraith), which I don't know what to do with, since I can't seem to
get access to my web space here at UMass. A very wide range of flavors of 1st
year Iceland Gulls were around for comparison, and the Thayer's was similar
in overall color to the darkest of these, which I think would put it at the
pale end of the Thayer's spectrum. It differed from the Icelands in that the
primaries were much darker than the rest of the body as mentioned in the previous
decription by Hector. Structurally, it was intermediate between Herring and
Iceland. The problem was that the tertials were busily patterned with dark and
light markings on the bird I was studying today, which is wrong for Thayer's
but right for Kumlien's Iceland. If individuals in this species complex can
be best represented as points along a continuum, I would put this bird mostly
towards Thayer's end of the Iceland- Thayer's gradient. Maybe it's a hybrid.
Frankly I'm a bit out of my league with these guys. An immature White-crowned
Sparrow turned up serendipitously as a blur in the background of my scope view
behind an Iceland Gull. It was in the thicket behind the left-most large compost
piles. And finally, a Fish Crow carried on nasally at the compost piles for
about an hour. Final tally: Iceland Gull (10+), Glaucous Gull (1, CT River),
Lesser Black-backed Gull (1 3w), Ring-billed Gull (1), Herring and Great
Black-backed Gulls - lots, Fish Crow (1), White-crowned Sparrow (1). Iceland
Gull breakdown - I had 1 adult, 2 very different looking 2nd year birds, and
various shades of 1st year ranging from ghostly pale to quite brownish.
NORTHAMPTON (report from Chris Gentes) I got to see the possible Thayer's Gull this afternoon and the thing about it that struck me was the pale edged primaries. It looked somewhat like the "paler juvenile" in Sibley to me. I never got to see the tail. I was fortunate to be on a trip with Wayne Petersen a few years ago when a Thayer's Gull was discoverd. He gave a great impromptu lecture about the bird. The field marks he was looking for were 1) "J Hooks" on the end of the primaries - ie pale edged. 2) solid dark across tail -i.e. 'banded'. He also talked about whether 'Thayer's Gull' is even a species since there is some interbreeding with Iceland/Herring in spots. He ended his lecture with 'if there is a 'Thayer's Gull' then what we are looking at is what is considered one.'
FEB 21 - Saurday
NORTHAMPTON (report from Tom Gagnon) The Thayer's Gull was observed
today at the dump on Burt's Pit Road. Also at least 10 Iceland Gulls were observed
as well as a "Kumlien's" Iceland Gull. Also seen was a Lesser Black-backed
Gull.
FEB 22 - Sunday
FEB 23 - Monday
FEB 24 - Tuesday
NORTHAMPTON (reported on Massbird by Andrew Spenser) I went down
to the dump on Burts Pitt Rd. in Northampton today to look at the gull being
reported as a possible Thayer’s. I saw this bird on Sunday, and came back today
to study it some more and get better pictures. While there today I also saw
a first basic Lesser Black-backed and somewhere around 10 or so first basic
Icelands and 1 second basic Iceland. I saw the possible Thayer’s today quite
well at about 45 feet, and I was able to get decent shots that I can send to
anyone who wants to see them. While the bird has been reported by many as a
probable or definite Thayer’s Gull, I disagree with this ID\, and tthink hat
the bird is either a very dark Kumlien’s Gull, or, more likely, an intergrade
Kumlien’s x Thayer’s (though closer to Kumlien's), for the following reasons:
First, and foremost, the feathers on the back are the wrong pattern; they are
white with a brown bar through the center instead of brown with white edges,
overall giving the back of the bird a really pale look at most angles. When
seen from behind, the back looks almost entirely white. The back feathers matched
the back feathers of the darker Kumlien’s present perfectly. The tertials are
very marked internally, with only one or two of the tertials having any significant
amount of solid brown in the center of the feathers, unlike the mainly solid
brown tertials of a pure Thayer’s. The tail, while banded, is not very much
darker than the underside brown color on the bird, and the outer feathers are
barred. I have not seen the tail closely enough to tell if the inner feathers
are barred to any significant amount, but I suspect they have at least some
barring in them. The bar on the upper side of the secondary feathers is quite
pale, and certainly not as obvious as on Thayer’s I have seen in Colorado. The
primaries show a little more than just the pale frosting around the edges when
folded; instead the pale edges seem to “bleed” into the inner part of the primary
tips. And, the overall bird is on the extreme pale end for Thayer’s. Marks against
Kumlien’s are that the primaries are significantly darker than the body, though
still on the extreme pale end of Thayer’s, in my opinion. This mark, and the
presence of a pale but noticeable secondary bar, as well as the large Herring
Gull like bill and sloping forehead more like Herring Gull, lead me to believe
it is an intergrade. Any other opinions on this bird’s ID would be welcomed,
and any comments on my notes on the bird would be as well
FEB 25 -Wednesday
NORTHAMPTON (reported on Massbird by Mark Faherty) I have posted
a page of gull pictures from Northampton, with some new photos and plumages.
There is no text (because I created the page by writing actual html code like
some sort of cyber- caveman), so you have to look at the file names (in the
last part of the url) to confirm what bird you are looking at. So it's like
a blurry quiz page, I suppose. http://www.people.umass.edu/mfaherty/noho_gulls.html
I added photos of the 2nd winter Iceland Gull I had mentioned in a previous
post since it is a relatively uncommon plumage in MA. The other 2nd winter bird
from 2/20 had a completely gray mantle, and very worn, very white coverts and
wing feathers, so it was probably more advanced than the bird in the photo -
maybe "2nd summer" plumage. I can't find a photo of that plumage anywhere in
books or online. Finally, I got a few photos of the 1st winter Lesser Black-backed
Gull first reported by Bob Bieda, I think. That's another plumage you don't
see too often in MA. Thanks to Andrew Spencer for expanding upon and better
articulating the reasons why the Thayer's/Kumlien's Gull is not a pure Thayer's
Gull. However, despite Andrew's comment, I'm not aware of any people reporting
or discussing this bird on massbird as if it were a "probable or definite Thayer's",
let alone "many people", so I'm not sure who he is strongly disagreeing with.
Perhaps people are being more reckless off-line. Gull expert Martin Reid has
provided comments on Chris Gentes' page that have confirmed my previously expressed
suspicions that the gull people would call this a "Thayer's/Kumlien's intergrade".
http://www.massbird.org/noho/thayers.htm
In the photos I added you can better see what Andrew and Martin are talking
about with the Kumlien's-like scapulars. I agree that the bird is somewhere
intermediate between Kumlien's and Thayer's. I think "dark Kumlien's" would
be a silly way to id this bird since overall "darkness" is not what separates
it from the dark Kumlien's present; it's the structure, the dark folded primaries,
and the Thayer's-like upper wing pattern. This is obviously not one of the normal
Kumlien's we get in MA, and it seems logical that it might be from a more western
population with a higher percentage of "Thayer's genes". Or....who knows. I've
decided to give up gulls for lent.
FEB 26- Thursday
NORTHAMPTON (report from Chris Gentes) No Thayer's. I only saw one
Iceland Gull with the usual gulls at the dump on Burt's Pit Road. On Wednesday
there were 2 Iceland Gulls. Regarding the Northampton possible Thayer's Gull
--- Andrew Spencer commented a few days ago against Thayer's because the "tertials
are very marked internally, with only one or two of the tertials having any
significant amount of solid brown in the center of the feathers, unlike the
mainly solid brown tertials of a pure Thayer’s." I found the following quote
that argues that solid brown in just a few tertials can indicate Thayer's.
"...a minority of Thayer's will have significant internal pale markings in the
tertials but will still show at least a reduced panel of solid brown somewhere
in the bunched feather group." --- Zimmer, K. J. 1991.
Plumage variation in "Kumlien's" Iceland Gull. Birding 23: 254-269
I've added a photo of the Northampton Gull's tertials that clearly show panels
of solid brown. http://www.massbird.org/noho/thayers.htm
THE CASE FOR THAYER'S GULL
NOTE: This section will be completed as time permits to work on it
photo by
Chris Gentes
TERTIALS
"...a minority of Thayer's will have significant internal
pale markings in the tertials but will still show at least a reduced panel of
solid brown somewhere in the bunched feather group."
--- Zimmer, K. J. 1991. Plumage variation in "Kumlien's"
Iceland Gull. Birding 23: 254-269.
Martin Reid, a gull expert from Texas was kind enough to offer his thoughts on this gull:
"Dear Chris,
If I saw this bird here in Texas, I'd call it a thayeri-kumlieni
intergrade. Where it is on that continuum is a matter of personal interpretation.
Reasons why I'd hesitate to call it a thayeri are: The pattern of the scaps
is too kumlieni-like, in that many of them have dark subterminal bars rather
than the thayeri pattern of a dark central "pentagon" - see the couple of feathers
close to where the light burns-out the scaps, for examples of this thayeri pattern.
The wing coverts have much more white in them than is typical of thayeri. The
huge pale tips to the longest rearmost scaps. No doubt you could find pics of
"thayeri" from the West Coast that are even paler than this bird - but are they
really pure thayeri? I suspect that birders in Oregon
or California may call this a light thayeri, while those in Newfie might call
it a dark kumlieni.
Cheers,
Martin Reid"
Martin Reid's Thayer's Gull Page
http://www.martinreid.com/thguinx.html
Martin Reid's Iceland Gull Page
http://www.martinreid.com/icguinx.html
Don Roberson, a bird identification expert, photographer and publisher from Monterey County, California sent this response regarding the gull:
"Chris --
Your Massachusetts bird is much paler than the vast majority of Thayer's out here, and I suspect it is within the range of variation for Kumlien's. I would think that if it were seen out here. I can't see the tail or secondary bar in the photo, though, and knowing what those characters look like would help.
As it happens, I've just posted a new i.d. page on Thayer's Gull.
http://montereybay.com/creagrus/MTYlistTHGU.html
Cheers,
Don"
It is rather ironic that Don discovered a Kumlien's Iceland Gull in California
- a bird much paler than the Northampton Gull, that was rejected as a Kumlien's
Iceland Gull by the California Rare Birds Committee.
http://montereybay.com/creagrus/ORA_kumliens.html
- Don's Comments on California bird
http://fog.ccsf.cc.ca.us/~jmorlan/bob.htm
- Photos of California bird rejected as Iceland
http://fog.ccsf.cc.ca.us/~jmorlan/bob1.htm
- Matt Heindel's Comments on this California bird
The Thayer's Gull in Denmark by Brian Small, and Martin Birch,
http://www.surfbirds.com/mb/Features/thayers-gull.html
Many photos of Thayer's Gull from a Japanese Website
http://larus.hp.infoseek.co.jp/a_Thayeri.html