A black-bellied dipper has been on the River Aire at Shipley in West Yorkshire for the past few days. It has been seen on the weir and under the railway bridge. In Britain, dippers are birds of the north and west that fly fast along streams and rivers, or bob up and down on rocks in the water. The black-bellied dipper is a continental subspecies with a dark stomach instead of the rufous stomach of our dippers. There was one on the Aire last October, which was probably the same one. So this March the black-bellied dipper may actually have been living here, having wandered across the sea to Yorkshire some time ago. Dippers are remarkable birds that regularly walk under water to find food. At present they are nesting in holes and on ledges beside the water. Because they have short, turned-up tails they were once thought, rather naively, to be related to the wren. Now it seems they may be connected to thrushes.