* A "laugh" of kookaburras - This is a playful option that refers to their distinctive loud calls.
* A "mob" of kookaburras - This is a more general term that could be used for any group of birds.
* A "parliament" of kookaburras - This refers to their tendency to gather in large groups, similar to a parliament of owls.
Ultimately, the choice of collective noun is up to you and depends on the context.