Orange to move and win in 5 half-moves.
First move. Note that all marked cells (among others) are not available for blue enter moves, yet open for orange moves.
First Attempt by Blue
Blue tries to invade the center (marked cells) to divide an orange flock there.
Orange can close the open path…
… and Blue cannot prevent the winning move by Orange.
Another Attempt by Blue
Blue now tries to stop the orange bird on the top right by attempting to close the path on the marked spot.
Now Orange must break through there first…
… and Blue, again, cannot prevent the winning move by Orange.