Is flock a common noun or a collective noun?

The noun 'flock' is a common noun, a general word for any flock of any kind.

The noun 'flock' is also a standard collective noun for:
  • a flock of birds (any kind)
  • a flock of camels
  • a flock of dolphins
  • a flock of ducks
  • a flock of geese
  • a flock of goats
  • a flock of kangaroos
  • a flock of lice
  • a flock of lions
  • a flock of pigeons
  • a flock of pigs
  • a flock of seagulls
  • a flock of sheep
  • a flock of tourists