I'd like them to fly over in random directions, but the OCD in me suggests to use them as compass.
They could fly left to right in all maps with negative X, and right to left in ones with positive X.
Plus, their direction could be diagonal, with a 15 degrees increase/decrease for each row of maps toward positive/negative Y, having random directions only in starting map, so that looking at them players could desume the map they are in.
And yes, I know there is the general map to show us where we are, as well as /pos command, but looking at birds to know where I am sounds poetical to me
