Thursday, August 30, 2007

Banded skua follow-up

In my posting about the CRESLI whale-watching trip I mentioned that we observed a banded South Polar Skua, which was photographed by Angus Wilson and other individuals. After cropping his images and sharpening the band detail, Angus was able to read the letters and contacted Markus Ritz & Hans-Ulrich Peter of Friederich Schiller University, Institute of Ecology, Polar and Bird Ecology Group. The information in their response is truely amazing. The short version is that the bird was banded in 2005 on King George Island in the Antarctic. Below are two of Angus' photos and an excerpt from his communications with Drs. Ritz and Peter:

Both photos copyright Angus Wilson
Markus Ritz & Hans-Ulrich Peter, Friederich SchillerUniversity, Institute of Ecology, Polar and Bird Ecology Group,
Dornburger Str. 159,
D-07743 Jena, Germany.

Dear Drs. Ritz and Peter,

On a recent whale watching/pelagic birding trip to the Great South Channel off Cape Cod, Massachusetts, USA organized by the Coastal Research and Education Society of Long Island, my colleagues and I observed a Catharacta skua (likely South Polar) wearing a legible ring (band). The position was N 41° 18.225', W 69° 17.968'. The bird passed over the boat once but was close enough for a few photographs to be taken that show the lettering of the ring (see attached images). We think the numbers are GC8 (or possibly, 83S). Is this likely to be one of the birds from your project? If not could you suggest other skua researches I could approach?

Kind regards,
Angus Wilson, Ph.D.



From: Markus Ritz
CC: Hans-Ulrich Peter

Subject: RE: Ringed Catharacta skua

Date: Thu, 30 Aug 2007 10:05:50 +0200


Dear Angus,


Great news! I am pretty much sure that the ring is ours and reads GC8. I remember the bird and it was indeed a relatively dark and large (most likely female) South Polar Skua. I ringed it at the 9.2.2005 and it bred successfully in the last seasons. Our investigated populations are at King-George Island / Antarctica (62° 12’ S, 58° 58’ W) were South Polar Skuas breed
sympatrically with Brown Skuas and also form mixed pairs (see pdfs). However, the bird you observed is most likely a “pure” South Polar Skua. Although it is believed that South Polar Skuas winter off the (east and west) coast of North America, your recovery is one of the first ring recoveries and therefore very valuable. We got another recovery in the north Atlantic from a hybrid skua and we have some satellite tracking information. We will most likely summarize these data in a small manuscript soon. I want to ask you to submit your ring recovery (via email) to our ringing centre:

"Beringungszentrale Hiddensee" am Landesamt für Umwelt, Natur & Geologie

Badenstr. 18

18439 Stralsund

Homepage: http://www.lung.mv-regierung.de/beringung


Because they may have problems finding the code of the plastic ring (it is encoded in a text field) it will be of help if you include the number of the steel ring: EA 139572.

Many thanks again for this nice recovery. It is always a great feeling to know that the bird I had in my hands is cruising the oceans and fascinates other birders. I am looking forward to getting more ring sightings from your team :-)


All the best!

Markus

Institute of Ecology at Friedrich Schiller University Polar and Bird Ecology Group

Dornburger Str. 159
D - 07743 Jena, Germany

http://www.uni-jena.de/Skua_hybridisation.html


Here is a link to more information on King George Island and ongoing research. Below are satellite images of the skua's banding location (credit - Google Earth). Click the images to enlarge. The distance between where the bird was banded and where it was photographed on the CRESLI trip, if it were to have flown in a straight line, is 7,146.24 miles!



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