Mar 21, 2012

Ringing Mew Gulls pays off

During the autumn one of our goals was ringing at least hundred first winter Mew Gulls (Larus canus). We achieved this and managed to put plastic rings on 173 first winter individuals. The first reading came in Stavanger 150 kilometers south. During autumn and winter six of our birds was seen there. Of these six three have remained in Stavanger and wintered there.

The first international reading came from The Netherlands. In mid November one of our birds was observed in Groningen (read more here). Less than a week after the second was observed further south in The Netherlands in Overijssel. In January we had one in Denmark, but we could not understand why we didn't get any readings from England. Was it the mild winter that made the gulls stay on grassland and fields and therefore make them difficult to read? However, today (20th of March) we got a double reading from River Severn at Newnham near Gloucester thanks to John Sanders. One was ringed here in Bergen 26th of September and never seen here after. The other one was ringed in 16th of August and observed until 4th of September.

This map summarizes reading of the first-winter Mew Gulls ringed in Bergen during autumn 2011:

All readings of first-winter Mew Gulls ringed in Bergen during autumn 2011 (blue). The bold line from Bergen to Stavanger represent 6 individuals. The red line is reading of a breeding adult ringed in a colony north of Bergen.

J4K3 is one of the birds seen in England. Here pictured in the city centre lake in Bergen 4th of September.

In addition we have an observation of one of the breeding Mew Gulls in England. This individual is one of the first records that documents that breeding Mew Gulls in Hordaland county winter in England. This bird was ringed close to a breeding colony north of Bergen in Knarvik. The bird was seen in Rutland Water west for Leicester by Steve Lister the 28th of February 2012.

J7R3 pictured at the breeding site at Knarvik 22nd of July 2011.

Thanks to the gull readers: Alf Tore Mjøs, Henk van Huffelen, Frank Majoor, Flemming Fragtrup, John Sander and Steve Lister.

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