Redesigned and much improved, with included perch.
This is an updated version of this https://www.thingiverse.com/thing:2181266
Here is a bird feeder to screw on the bottom of an apple juice bottle you buy at Wallmart https://www.walmart.com/ip/Great-Value-100-Apple-Juice-96-oz/10415325. This is big enough for whole (black shell) sunflower seeds to be used. There are holes in the base to allow rain water to escape.
This has no base and the bottle needs to be hung. Punch a hole in the top and put a string or anything to hang it. The bottle will need some air flow on the top sides to stop condensation from forming on the inside and getting the seed wet. There is also a bar on the bottom to hang a weight to keep the bird feeder more stable.
Printed with no support in ABS.
The author hasn't provided the model origin yet.