It is interesting how different birds fly in different formations. The Black-Headed Ibis on their evening flights to roost seem to always fly in a single file formation – as opposed to Egrets that fly in crowded clumps or cranes that fly in a more traditional formation like geese.
Taken with EOS 10D against the setting sun at a lake south of the Wasgomuwa Strict Natural Reserve with the 100-400 @400mm, f/7.1, ISO400 at 1/400.