My favourite build of the four: an arcade machine, which requires the hack of using dispensers to place armour stands, and using pistons to push those armour.
Make one in the image lol imo though its a bit too clustered together to really have that bird flock feel though, theres always a couple stragglers as well.
To begin, place your chest wherever you'd like your collection point to be and attach a hopper to the back of it. To do this, crouch, and face the back of the.