The foraging sites of 854X

09/02/2016, the objective of the day: to identify the characteristics of the foraging sites of 854X, the Bewick’s Swan “sentinel” equipped with a GPS transmitter in Siberia.

The data transmitted from the arrival of the swan in the Delta of Evros indicate that it forage exclusively in the Turkish part of the Delta. The reason is simple: this area is covered by 99% of rice fields. Natural habitats, which contribute to the exceptional biodiversity of the Greek part of the Delta, were completely destroyed on the Turkish side. It is striking to observe a satellite map: east of the river, everything is a deep green: it is the rice fields. While to the west, a patchwork of colors of various shapes and sizes can be observed. There are obviously areas that are cultivated on the Greek part but not intensely while in coastal areas, salt marshes and lagoons stretch out of sight.

Satellite vieuw of the Evros Delta. The border between the Greece and Turkey follow the stream.
Satellite view of the Evros Delta. The border between Greece and Turkey follows the course of the stream. Monoculture of rice fields is widesread on the Turkish part of the Delta.

Let’s go to Turkey. A part of the rice fields is completely dry, the stubbles left after harvest line up in endless furrows. Another part is partially flooded, the bottom of the grooves being filled with water probably consecutively to the rains of the past week. A third part is completely under water, forming lakes of several km². It is on these flooded fields that gathers the majority of swans. Part of the area cannot yet be surveyed because it is under military control.

Most swans are found together in 4 huge flocks of 1500 to 4000 individuals. Small groups with a few dozen to a few hundred swans are scattered here and there. The large flocks are composed of three species of swans: Mute, Bewick’s and Whooper. All are feeding on the roots of the rice plants that were planted last spring. All sites where 854X has been located, and that could be visited, are indeed flooded rice fields.

Rice stubbles in Turkey: the essential feeding grounds of Bewick's Swan wintering in the Evros Delta, 09/02/2016 (photo Didier Vangeluwe).
Rice stubbles in Turkey: the essential feeding grounds of Bewick’s Swan wintering in the Evros Delta, 09/02/2016 (photo Didier Vangeluwe).

Apart from swans, there is almost no other birds in this part of the Delta. This is probably the consequence of the disappearance of natural habitats and the development of rice monoculture. A very important hunting pressure is another explanation: at regular intervals in each rice field one may see hunting huts when gun cartridges litter the ground by the hundreds. At 14:45 in the middle of a group of 2,700 swans feeding in a flooded rice field near the village of Enes, there he is. 854X is carefully preening.

854X in sight in Turkey, 09/02/2016 (photo Didier Vangeluwe).
854X observed in feeding grounds in Turkey 09/02/2016 (photo Didier Vangeluwe).

It’s a chance because yesterday it was located 26 km north, near the village of Ipsala. There are exactly 179 days we were together at the mouth of the river Yuribey on the shores of the Arctic Ocean.