Tweeters,

The recent bickerings on Tweeters over the ethical questions of leaving the
injured Kumlien's Iceland Gull now present in The Port of Tacoma alone
(rather than attempt rehabilitation of its broken wing) for the benefit of
some birdwatchers " Life Lists" reminds me there is an equally strident
(and perhaps just as interesting) debate going on in the scientific
community regarding this species status between this and the Thayer's Gull.
Briefly, it goes like this: in the arctic, there is a variation in
pigmentation from east to west in the Iceland Gull (Larus glaucoides
glaucoides), a small 4-year gull. It is palest in northern Europe (the
nominate subspecies glaucoides), where all plumage sequences resemble that
of a 2/3rd-sized Glaucous Gull. Greenland and southern Baffin Island birds
have more pigmentation (especially in the primaries) and are known as
Kumlien's Iceland Gull (Larus glaucoides kumlieni). West and north from
southern Baffin Island in the Canadian arctic, pigmentation increases (from
gray to black in the primaries). These were descibed initially as a new
species, Thayer's Gull (Larus thayeri) in 1917, then subsequently as
another subspecies of the Herring Gull (Larus argentatus thayeri) by the
AOU 1957.

Then from 1959 to 1961, biologist N. Smith undertook an indepth set of
experiments in southern Baffin Island in attempts to shed light on the
isolating mechanisms in the various gulls nesting in that region. He
ascertained the four species nesting there were "sympatric," that is,
apparently closely related (sibling species) were coexisting without
interbreeding. This study, in part, involved capturing hundreds of gulls
of four species nesting in that area (Glaucous, Herring, Thayer's, and
Kumlien's Iceland), then altering their appearance by hand painting their
orbital rings and wingtips the colors of the "wrong" species and then
watched their behavior. He concluded the gulls used eye color and contrast
of their eye (varying degrees of pigmentation) and wingtip pattern (again
variation in pigment) as recognition marks. Results of thiese outstanding
model experiments led him to conclude color and pigmentation of these gulls
soft parts (iris ring and eyes) and wingtip pattern were crucial in
"correct" pair formation" and were, therefore, isolating mechanisms between
these species. In other words, if pigmentation was altered (painted a
different pattern and color by the researcher), the gulls got confused and
pairs were "broken," or they paired with the "wrong" mate, resulting in
sterile offspring. Smith then concluded Thayer's was a distinct species and
not just another subspecies of Iceland Gull.

The conclusions of these elegant, bold, and original experiments were to
become textbook examples in evolutionary biology as in: Futuyma, D.J.
1986. Evolutionary Biology, 2nd ed. Sunderland, MA: Sinauer; and Liley,
N.R. 1981. Isolating Mechanisms. Pp. 302-325 in The Oxford Companion to
animal Behavior (McFarland, D. Ed. Oxford, U.K.: Oxford Univ). These
conclusions were also the basis for the AOU in separating THAYER'S from
ICELAND GULL, resulting in the "extra" species now gracing the bird field
guides.

However, shortly after Smith's results were published (Smith, N.G. 1966.
Evolution of some arctic gulls (Larus): an Experimental study of Isolating
Mechanisms. Ornithological Monographs No. 4:1-99. American Ornithologists
Union), other biologists began to question Smith's ability to perform these
experiments given the challenges of the terrain, the complexity of the
experiments, and time limitations Snell, in particular, published an
8-point refutation of Smith's work (Snell, R. R. 1991. Conflation of the
Observed and the Hypothesized: Smith's 1961 Research in Home Bay, Baffin
Island. Colonial Waterbirds 14 (2):196-202), asserts Smith would have been
physically unable to perform all the work he claimed, given ice conditions
and ruggedness of the fiord landscape in southern Baffin Island, etc. and
also because Smith was concurrently studying similar mechanisms in the
Semipalmated and Common Ringed Plovers (which also breed synpatrically in
southern Baffin Island). Snell advises that all conclusions of Smith's work
should be questioned.

Other researchers have gone to Home Inlet on southeastern Baffin Island and
elsewhere in the arctic to replicate Smith's experiments, without success
leading W.E. Godfrey (1986. The Birds of Canada, 2nd edition. National
Museum of Natural Sciences, Ottawa) and others to reassign Thayer's as a
subspecies of the Iceland Gull. Perhaps most importantly, others have noted
Thayer's and Iceland freely interbreeding in the very area where Smith
studied gulls (Gaston, A.J. and R. Decker. 1985. Interbreeding of Thayer's
Gulls (Larus thayeri), and Kumlien's Gulls (Larus kumlieni) on Southhampton
Island, Northwest Territories. Canadian Field-Naturalist 99:257-259).

Smith, not remaining silent, refutes Snell's paper (Smith, N.G. 1991.
Arctic Gulls 32 Years Later: a reply to Snell.[I have a copy of the paper
but the journal isn't cited!!! Anybody in Tweeterland know what it is?])
with varying comments (such as "Yeah Snell your right on this or that
point, but only because the chart is mislabelled, however, the data is
correct" but at other times Smith responds with reasoned responses).

More recently, it is recommended that the AOU follow Canadian biologists in
treating Thayer's Gull as a subspecies of the Iceland Gull (DeBenedictus,
P.A. 1987. Thayer's Gull: gleanings from the technical literature. Birding
19:29-32), however the most recent AOU (7th edition, 1998 AOU Checklist of
North American Birds. Allen Press, Lawrence KS) continues to treat Thayer's
as a separate species.However, the AOU states "the relationships of these
populations requite further study."

My experiences with Iceland Gulls in Washington have been an exciting. On
25 November 1990, I observed a "possible" 1st-winter Iceland Gull at
Walulla in Walla Walla County, a report later accepted by the Washington
Rare Birds Record Committee. On 7 December, I observed another 1st-winter
bird at Electric City in Grant County, prompting me to head to Newfoundland
in winter on the WINGS trip (a trip which is targets Dovekie, Black
Guillemot, gulls and boreal passerines) to study first-hand this species.
As an aside, Newfoundland is delightful in winter, as improbable as it
might seem, memorable were the spectacular seascapes, wonderful walks
amidst spruce taiga and tundra landscapes, and
with numerous "Irish" pubs for visits during the non-birding hours (which
are long at thisseason).

On this Newfoundland visit, I insert my initial observations of the
numerous Iceland Gulls there at this, the single best site in North America
to observe this species (in winter):

On checking into the Battery Hotel in St. John's, I drew the drapes and
peered down the bold granite escarpments guarding the harbor to the cold
waters below. Noting gulls roosting on a wharf, I set the scope and began
peering through the somewhat warped glass. I noted 1 or 2 1st-year
Glaucous, several Great Black-backed and many Iceland Gulls roosting.
Among them were several smaller gulls; distance prevented me from
identifying them. Excited, I collected my scope, put a jacket on and
bounded down the steep, snowy slope, noting flocks of robins flying about.
>From some weedy areas where snowmelt had been accelerated, a pipit flushed
and flew off, calling loudly. Reaching wharf levels, a bonus was
present...a sewage outfall! There were gulls everywhere, a view hidden
from the hotel window because of the steep slope.

It turned out the small gulls were immature Common Black-headed Gulls, a
new species for me. I observed this species for a long time, struggling to
imprint its structural differences from the Bonaparte's Gull. More
observation would be necessary before I could allow separation of these two
species on jizz alone.

Studies of the many Iceland Gulls pattering above the outfall confirmed in
my mind that my two observations of 1st-winter Iceland Gulls I've reported
in Washington state were bona fide. Now it remains to adequately document
them with photographs. I contend identification of this species should not
be as controversial as it has been on the West Coast of North America.
Zimmer, in his invaluable aid (Zimmer, K.J. 1991. Plumage variation in
"Kumlien's" Iceland Gull. Birding 23:254-269)to field identification of
this species states determination of individuals, particularly at the
endpoints of their clinal variation (between Thayer's and Iceland Gulls),
should be relatively straightforward.

I found the dramatic weather changes about the harbor exciting. In this
one afternoon, there was fog, rain, mist, wind, then calm, then bright
sun!"

....The first moments of our tour were eventful as we motored up Signal Hill
in the pouring rain amidst scrub willows and bouldery terrain and Bruce
called out "Snowy Owl!" The owl shortly flew off as the van halted and
soon perched by a frozen pond, peering at us nervously. Susie said it was
the darkest Snowy Owl she had seen and Stu remarked itwas probably an
immature female, which are large and typically very dark. I thought it
interesting a Snowy Owl was but five minutes walk above the Battery Hotel.

We drove upwards into the fog and rain at Signal Hill's summit and read the
interpretive signs explaining this was the site Marconi received the first
Trans-Atlantic wireless message from Ireland early in this century. Other
directional signs pointing into the open Atlantic gave distances to various
European capitals, the closest only four hours flight away.

Moments later, we began by checking the sewer outlets below the Battery
Hotel. I seemed to be the only participant really excited by the gulls on
this trip, so I offered a challenge to the group, to set as a goal,
identification of every plumage of every species we noted. We were to see
two two-year species (Common Black-headed and Bonaparte's), one three-year
(Ring-billed), and five four-year (Herring, Iceland, Lesser Black-backed,
Glaucous and Great Black-backed) Gulls. If my calculations are correct,
that means 27 identifiable plumages might be possible. I believe we saw
only 1st-year on the Bonaparte's Gull, mostly 1st-year on the Common
Black-headed, only adult on the Ring-billed and only adult on the Lesser
Black-backed Gull. For the 4-year gulls, I believe we observed every
plumage possible, though, as expected, relatively few individuals of
Iceland and Glaucous Gulls in their third winter dress. The sewer outfall
seemed very good for Iceland Gulls, upwards of 200 were present, making
this very possibly the premier location in North America for viewing this
species. Common Black-headed Gulls were present in good numbers here too,
surely making this a prime spot for this mainly European species.

Interestingly, another sewer outfall a short distance south from the
Battery Hill outfall and just below the main business district held a
different assortment of gulls. I visited this other site on four occasions,
twice with the tour. On all occasions, larger gulls such as Herring,
Iceland and Glaucous Gulls were present, but no Common Black-headed. I
observed a sort of pecking order, whereby the Glaucous Gulls always
occupied the center of the roiling waters, right above the outfall.
Herring Gulls were next in line, occupying the space several meters away
from the upwelling. Finally, Iceland Gulls occupied the area farthest from
the outfall, perhaps 3-10 meters from the center.

Mostly frozen Quidi Vidi Lake was host to an impressive number of roosting
gulls, which were probably birds from the nearby dump. On this, our first
visit, we left the van briefly, as the rain continued and noted: Common
Black-headed Gull-25, Bonaparte's Gull-1, Ring-billed Gull-3, Herring
Gull-4,500, Iceland Gull-25,
Lesser Black-backed Gull-1, Glaucous Gull-50 and Great Black-backed
Gull-750.


Andy Stepniewski
Wapato WA
steppie at wolfenet.com