The Incredible Evros Delta




Guidelines to follow during your visit

Bewick’s Swans leaving their roost in the Evros Delta, 02/02/2016 (photo Didier Vangeluwe).
The Incredible Evros Delta
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5100, 5300, maybe even 6000! That is the number of Bewick’s swans counted the last days by ornithologists working for the Evros Delta National Park. The previous record was set around 4500 individuals seen during the previous winter. The number of Bewick’s swans hibernating in Greece is therefore still growing, while at the same time the flocks observed in the area of the North Sea are at their lowest. For this reason, scientists of the RBINS are there to help with the counting.

It is not an easy task to count the swans in the Evros region. Indeed, the Delta is shared between Greece and Turkey, making it difficult to carry out coordinated counts; there is also no local team of ornithologists on the Turkish side of the border region. Part of the delta is also under military control and can therefore only be visited occasionally and under strictly controlled conditions. In addition, the area where swans are present is very large, about 350 square kilometers. Moreover, a part of it is inaccessible when the river flow is so strong that areas adjacent to the main branch are flooded. Furthermore, Bewick’s swans are not the only representatives of their genus to hibernate in the Evros Delta. It is also the case for thousands of mute swans (from the steppe – or ancient steppes – of Ukraine and Southern Russia) and whooper swans (most likely originating from the taiga of Siberia). The counts are therefore often slow and difficult as it is essential to carefully make the distinction between the three species. But the Greek team is particularly experienced.

Tagged swan

Starting today, and for 10 days, the Greek and Belgian teams are joining forces to study the behaviour of swans in the Evros, their distribution between the different lagoons, and their demographics by determining the proportion of young and brood size. The aim is also to go and see each site where the Bewick 854X, equipped with a GPS transmitter on 14/07/2015 in the tundra of Yamal (Siberia), has been located since its arrival in the Evros Delta on December 12th, 2015. That will create the opportunity to accurately determine the habitats used by this ”sentinel swan” and their relative importance. Such data are very useful for the conservation of the species which provides  the possibility, if necessary, to propose appropriate management measures. The GPS localization of the transmitter was set at 1 hour intervals. This will engender even more accurate data in the coming days. The procedure will be limited in time because it obviously demands a lot of energy and it could drain the solar battery.


Today, the sun is shining in the Evros. Daytime temperatures range between 10 to 15 °C. It turns out that almost all Bewick’s swans left Greece to forage in Turkey. Moreover it turned out that they did not come back on the Greek roosting places before sunset. We have counted barely 150 individuals arriving at the roost before dusk. But the evening was not lost! At 16:48 and then again at 17:11 it is in a deafening roar when two compact waves of 4500 ruddy shelducks in total arrived at the same marsh just south of Drana lagoon. In the case of Europe, this only happens in the Evros Delta! We will get up tomorrow at 6:30, before sunrise, to see if the swans were indeed coming to sleep in Greece so we could try to count them. And perhaps also to observe 854X!

Follow the adventures of our scientist Didier Vangeluwe.

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