Terms most people know:

- A flock of seaguls
- A gaggle of geese
- A ballet of swans

Terms some people know:

- A flamboyance of flamingos
- A murder of crows
- A peep of chickens

Terms no one knows:

- A brace of grouse
- A trembling of finches
- A piteousness of doves

Terms I completely made up a yesterday (but could probably fool some people):

- A handbag of hummingbirds
- A carafe of sparrows
- A mailbox of quail
- A sit-com of owls