Lachstern

Vandaag trof ik vijf ongeringde jongen terwijl men alles zou ringen dit jaar.

Hieronder wat uitleg;

Hello Fred

there are no breeding pairs in Denmark this year (same as last year). The former breeding spot at Filsø (Esbjerg region) has been abandoned due to habitat change (succession). According to data from DOFbasen.dk no new spots are claimed yet.

This year we had difficulties finding chicks because of extremely high and dense vegetation cover (mainly thistles). It was a kind of “hide and seek”. We got hold of 10 chicks that have been ringed, 1 of those died, so there might be still 9 ringed alive and kicking yet. Unfortunately there is a substantial number of chicks we didn’t get hold of, thus no rings on them. We saw them feeding in the tidal zone after they had left the fenced area. They did that one by one, not at once, so we could never be sure how many they were. Most of those moved out of the fence not before they were fledged, perhaps a consequence of the dense plant cover. As a lucky coincidence, this way they might not have met the 3 raccoon dogs which mainly fed on common tern eggs and chicks outside the fenced area.

I am hoping for more observations from Holland and other places along the migration route so that I can get a better impression of the actual chick number fe by the ringed/unringed ratio. As for today the estimated (minimum) number of fledged chicks is 15.

During ringing we missed particularly the older chicks. So the next days I expect you to see a few more unringed chicks before the first ones with rings might come along.

Best Regards