Place a bird trap near (but far enough away from) the pool (I'm assuming the pool is already full of shit). Vulture goes in; cage shuts; somehow the cage ends up at the bottom of the pool. Must have been the other birds. You now have a dead vulture.

Nice try PBP writer, but Hitchcock was a master of suspense, not horror. Trying to equate the anxiety of The Birds and thinking it was about horror just shows they have little literary discernment.