About the birds and … erosion

This is river Sava near Šentjakob, Slovenia, shot with Nikon 1 J1 on a Rokkaku kite.

In september 2010 it swelled enormously during the torrential rains and its truly exceptional flow – exceeding 1.200 cubic meters per second – of this barely tamed river destroyed almost 600 m of the left bank channel wall, reclaiming and ‘renaturalizling’ the bank.

It was a major disaster – but then something nice happened.

In the early spring of 2011 European sand martins (Riparia riparia, a type of swallow) arrived from Africa and found the new, natural riverbank exremely suitable for their type of nesting: diging deep burrows in the sand of the upper part of the vertical river bank to avoid predators.

(Sand martin, Riparia riparia. Photo courtesy Alan Vernon)

The large notch in the riverbank was growing and destroying more and more of the fertile soil, so a team came with the heavy equipment to restore the river channel. But at the time over 80 pairs of sand martins were already nesting there – and sand martins are a strictly protected species in Slovenia. Ha!

(Sand martins nests in Sava bank near Šentjakob. Photo courtesy of Tomaž Jancar, DOPPS – BirdLife Slovenia,)

So they had to compromise: a retaining wall was build upstream to divert the power of Sava away from the dent and thus prevent further bank erosion – and sand martins got to stay here.

Their burrows are currently waiting for them to fly back home in March – and as the kite is a quiet beast, we will surely try to approach stealthily from above and get some photos of sand martin families 😊.

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