This watercolour is the sketch of a river bank where the Sand Martin (Riparia riparia) nests, this little swallow breeds colonially and dig your nests in tunnels. In spring they arrive on our rivers from Africa wintering quarter. They need to find vertical river bank to erosion and a layer of silt and sand in which their dig galleries. You could find maybe a few hundred up to 6,000 nests! Unfortunately where I live are becoming fewer because of the river systems that no longer offers available habitats, sometimes nesting in gravel pits or sand, replacing the banks river I'm love this small animal (the subject of my thesis, 15 years ago!!), but is not easy to paint, due to flights acrobatic, better when they looking out the nest!!