Procedural Birds Flocks is used to fly your 3D scenes in seconds. Its comes with different flocks types to fly your environments. You can choose any type according to your scene. Many parameters are given in each type to control flocks.

Procedural Birds Flocks addon comes with 10 birds containing 3 different collections 

• Birds Flying 1
• Birds Flying 2
• Birds Gliding

or you can pick any birds from collections by using eyedropper in Bird 1 and Bird 2 slots.

Watch video for more detail Here