The birds represent 1's. The spaces represent 0's.
The arrangement of birds on the wires (with the flying bird) is:
01001101 01001111
01010110 01000101
Which means MOVE in binary (note for nerds: actually it translates to four numbers which represent those letters in the two most common text encodings [ASCII and UTF-8]).
If the flying bird flies away, it changes to:
01001100 01001111
01010110 01000101
Which translates to LOVE.