Tuesday, 4 October 2011

The (Dark Phase) Long-tailed Skua Saga

With this evenings dinner party rapidly approaching there was little time for gallivanting, with the first part of the morning given over to peeling and the second collecting a few last minute items. The day had started off rather dull but with frequent patches of sunshine not at all a bad day, I was lucky to catch one of the more prolonged spells of the warm stuff.

Some might say (Oasis) that we don't appreciate what we have close at hand, but I for one do not subscribe to the theory. Even a chore as mundane as shopping has a massive up-side when you live in Weymouth - just look at this. Exactly 8 minutes walk from my house we reach the Inner Harbour with its congregation of various small watercraft.

Looking towards the Town Bridge from the west, is where the Charter Sea Fishing Boys moor their boats,

while looking from the opposite direction the Outer Harbour caters for

larger craft such as this Weymouth registered (WY) Scallop Dredger probably the largest local fishing boat to berth here.

Looking towards the Harbour Entrance and seaward other vessels are secured such as

Pelican of London a regular visitor to the town

and the Sail Training Vessel Royalist.

(Dark Phase) Long-tailed Skua - The Story So Far

It's coming up 3 months since I was on St Paul one of the 2 Pribilof Islands in the Bearing Sea, off the coast of Alaska. Being skillfully guided by Forrest Rowland, then working for St Paul's Tours,

on the afternoon of the 14 July we had been delighted by the sight of what Forrest described as the largest 'day count' of this sleek seabird on the islands.

Unfortunately never at point blank range we had observed many both in flight and at perch over a couple of hours period,

and breaking my personal day total of 7 into the bargain.

That's when this flew over the ridge and into view........

A form of Long-tailed Skua that most, if not all, authorities don't accept as existing! There has been much excitement and debate, especially on the other side of the Atlantic, since the photographs of this bird were published not only on this Blog but on a number of other websites worldwide. From those, many eminent, who have ventured an opinion it looks quite good that this could well be as claimed. If you would like to add your voice to the debate please do not hesitate to do so through these pages, or via the links below.

From Forrest Rowland
To Paul Guris
  • Date: Thu, 29 Sep 2011 13:49:24 -0600
  • Subject: Re: Forrest's Dark Jaeger (Summarized Info)
I've CC'ed Bagsy on this. He was the client with me who also observed the bird, took some photos and kicked up quite a conversation on his side of the "pond" as well! He'll be interested to read some of the commentary running through the mill.
Fun stuff!!!

On Thu, Sep 29, 2011 at 1:44 PM, Paul Guris <paulagics.com@gmail.com> wrote:

We've been having a side conversation on this so I decided to summarize everything in one place. I also added Louis Bevier (since he's been in on the side chat), Todd McGrath,and Mary Gustafson.

Forrest's photos that kicked this all off:

Surfbirds discussion of the exact same bird photographed independently Jan. 14 (5 days after Forrest):

The blog post by the original Jan. 14 photography mentioned in Surfbirds:

Comment in Surbirds thread by Alex Lees:
from Kjellen (1997)

No dark-phase bird was recorded among the 600 Long-tailed Skuas observed during the expedition*. Apparently, only two dark birds have ever been described. Both originated from western Greenland and are now in the collection at the Zoological Museum in Copenhagen. According to Boertmann (1994). both showed subadult characters, although the central tail feathers were fully grown. It is doubtful if these two skins really merit the claim of a dark phase in adult Long-tailed Skua but dark birds are not uncommon among juveniles (Cramp & Simmons 1983, N. Kjellen. pers. obs.).

*from the Kola Peninsula in the west to Wrangel Island in the east __________________
Dept. of Zoology, MCT/Museu Paraense Emílio Goeldi, Brazil.

Dutch Birds article linked to by Brian S in Surfbirds thread which claims the Greenland birds are adults:

And a follow-up from Louis:
I have Boertmann (1994) right here:

pg. 35, right column, under "Remarks" for longicaudus: "A dark morph seems to be very rare (e.g. Furness 1987). Recent reports from Greenland have been non-breeders (Kampp 1982; Dändliker 1988). The two dark morph skins in ZMUC (both from West Greenland) both show some immature plumage characters, although both have fully elongated tail streamers."

I can download the Kjellen paper from the Ibis later and send that to anyone who wants.

I think this is fascinating that you have a bird that fits these earlier descriptions. The barring may not be indicative of age in this case. It would be good, though maybe impossible now, to get as much on the bird as possible. Bill morphology would help, but maybe you need a bigger oar!

That should be enough to digest for now.

Paul A. Guris
See Life Paulagics
PO Box 161
Green Lane, PA 18054

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