Question to Ponder #1

Can anyone derive a function that best determines the bird-spacing for flocks of birds sitting on over-head telephone lines?

The spacing seems amazingly uniform and must be determined by each individual birds "personal space"; or are other factors at play here?

- wingspan?
- Some sort of fluid dynamics anomaly that occurs as air flows between each bird?
- the frequency (Hz) of the current traveling through the wires?

The next time you are traveling and see a multitude of birds sitting on the lines, notice how far apart they are and consider why.