The transfer of data from the mutual birdwatchings was done with the cooperation of the Bulgarian Ornithologist Center at the Institute of Biodiversity and Studies of Ecosystems at the Bulgarian Academy of Sciences.
This is a great success for the researchers of the species because until this moment very little was known about the migration of these birds. The data about second sightings of birds with rings, marked here in Bulgaria or abroad is very useful in the clarification of the migration roads of the birds, of their places for rest and feeding and of a large number of their biological and ecological peculiarities.
We would like to remind that the marking of young Sandwich terns was done for the first time in Bulgaria at the Pomorie Lake in 2010 and continued in 2011 and 2012. A total of 280 birds were marked for the whole period of the bird ringing and radio transmitters were attached to seven of them.
