The still, warm air is dancing with tiny flies. Sand Martins flit and swoop among them, catching their fill. The colony is in the riverbank, a dense, uneven cluster of about 40 holes with about 50 more spread further apart in irregular lines to the east where the bank is lower. Around the colony the air is leaping with birds, pulses of quiet, grating, insistent trilling filling the air as they whizz about. There is no sign of the Hobby I saw yesterday although a colony such as this appears to offer easy pickings. Two of the holes are obviously occupied, their residents sitting in the entrances, but the others seem at first inactive. Constant scanning with the binoculars reveals occasional, discreet visits to other entrances. We map the burrows – a tricky task – and carefully mark each hole with a cross to record visits by their owners. At first, progress is slow, but as darkness gathers, visits become more frequent. After an hour we have recorded 70 occupied burrows, a good increase on last year. These birds are opportunists, often shifting their colonies from year to year as riverbanks collapse or gravel and clay extraction progress.
Schoutenwaard, Lower Rhine valley, The Netherlands, June 2012
8 June 2012 -