Young House Martins Delichon urbica (Fr. Hirondelle de fenêtre) begin to gather into flocks after they have fledged. They are bonding in preparation for flying off to Africa for the winter. Dozens of them will perch on the electricity wires in our street at this time of year, and for a few days they took to perching on the string course just under the eaves of the house across the road. I wonder how many of them will make it back in the spring?