Tuesday 9 December 2014

Plotting the migration of our Sedge Warblers

Since 2009 we have ringed 2,874  Sedge Warblers either passing through or breeding on the Teifi marsh.
With news this week from the BTO of one of our birds being controlled in France, another dot can be added to our Sedge Warbler movement map.
This latest recovery was down in the South of France at Reserve Naturelle de la Maziere in Lot et Garonne. Ringed on the Teifi on the 16th July 2014 and recaptured on the 4th August, just 19 days later.

Migration across southern Britain can be seen from the map with many recoveries from Icklesham where huge numbers of birds are caught as they migrate through before crossing over to France.

Most recoveries are in the Loire Atlantique and other Sedge Warbler ringers will recognise the locations Donges, Frossay, Tour aux Moutons, Feu de la Calotte, La Tertre Rouge. Presumably a lot of French ringing effort is concentrated in these marshy areas which provide good habitat on migration. Sedge Warblers need to lay down fat reserves before undertaking the rapid long haul flight across North Africa and the Sahara to West Africa so are very dependent on good feeding areas rich in aphids. This emphasises the importance of conserving these wetland areas and slowing down man's interference with the habitat by drainage and development.
There is still a big gap on our map through Spain and North Africa with the next location being their wintering area in Djoudj National Park in Senegal where two of our Teifi ringed Sedge Warblers have been recovered.
This year our total of Sedge Warblers ringed was 571. Seventeen retrapped adults from previous years represent either site faithful breeding birds or migrants passing through on the same route.

Hopefully some ringing news soon if the wind ever eases enough to open some nets. The full moon has slowed down our night time lamping too.

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