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Saturday, 12 March 2016

Wintering Dunlin in Kerry - where do they come from?

The ringing and satellite-tagging of birds has thrown up some astonishing findings in recent years. Simply putting a metal ring on a bird is one thing, but usually relies on that bird being re-captured or, more often, found dead and then reported by a member of the public sufficiently interested or motivated enough to report it.

Colour-rings, or leg rings with highly visible serial numbers, or unique colour combinations, adds another level of visibility to the process, and increases the chances of a ringed or tagged bird being reported alive, and usually by birders. The amazing advances in digital photography in particular has been another factor, where such ring numbers or colour combinations can be more easily read from a photo, something virtually impossible with a 'live' image of a bird through a telescope. Try working out the four-colour combinations of rings on both legs on even a closely observed but fast-moving Sanderling, as it sprints into and then away from breaking waves on a shoreline, and you'll understand. One half decent photo will usually clinch it. And reporting such a sighting on the internet is now usually straightforward, and usually - not always - gets a prompt response from those that ringed it.

We've seen examples of this recently in Kerry with Glossy Ibis (see HERE) (France), with Dunlin (HERE)(Poland), with Common Gull (see HERE and HERE)(Iceland and Lough Mask), and many others, and the findings from each are remarkable.

Ringed Dunlin, Black Rock, February 2016 (David O'Connor).

David O'Connor photographed this Dunlin at Black Rock in February, and just got word back that it was ringed in Poland, the third such ringed Dunlin from Black Rock this winter AND from the exact same ringing scheme in Poland. 

They were all ringed at the mouth of the Vistula River east of Gdansk. This particular bird was ringed as an adult bird in July 2013 and, in a straight-line distance, travelled 1.909 km to spend at least part of the winter on a Kerry beach. It would be great to know, did it breed in that part of Poland (the species does breed there, so it's likely), or was it already on an epic migration from elsewhere? 

Surely our wintering Dunlins come from... well, from 'north' of here? Scotland? Scandinavia? Russia? Well, these three have seemingly come to our Kerry winter from nearly 2000 km directly EAST of us.

We have so much yet to learn about the movements of even the commonest of our migratory birds.