Hundred of Barn Swallows and Sand Martins in the reed bed of Gautegiz Arteaga's marshes

As in every migratory passage, during the prenuptial and postnuptial migrations, the reed beds of the marsh are usually used by several of passerine birds as resting places to spend the night during their long migrations.

They are species like the Barn Swallow and Sand Martin which are diurnal migrants that in the evening approach to roosting places to overnight every day. They use reed beds of wet areas that they find in their flyways, where hundreds or even thousands of these specimens bring together finding protection against predators. They choose above all reed beds that are permanently flooded and surrounded by water in which predators have almost impossible to approach from the land without raising the alarm, as the water and the brittle structure of the reed bed, become their presence more than evident.

During the first days of spring, we have seen that has created the first roosting place in the reed bed of the marsh in Gautegiz Arteaga, and that it is used by a big number of birds. In those first dates of migration, we can highlight that large groups of Sand Martins from up to more than 1000 specimens together with some Swallows that have been using these sleeping places every day.

These groups are the prelude to many groups of Swallows and Sand Martins that are still to come and will also use this marsh as a stopover to rest and to survive to storms in their way to breeding places.

From the Bird Center it is carrying out a monitoring and marking campaign in this roosting place every year during prenuptial and postnuptial migrations. An interesting fact is that among all the birds marked last week, they have been recovered three specimens of Sand Martins ringed in the British Isles. These birds have surely been ringed in their breeding colonies or roosting places in British Islands, and they have probably been marked before starting their journey to spend the winter in Africa; for this reason we can suppose that a lot of British Sand Martin's groups use these marshes of Urdaibai as a resting places in their way to breeding places in England.