If you're looking for a more traditional hanging style bird feeder please see the other one I created here

This bird feeder uses four (4) suction cups to allow you to mount it to any flat vertical surface like a window or a vinyl fence. 

The suction cups need to have pre-attached screws and be 4.8mm - 5mm width, and at most 11mm length. The design was made for these suction cups with screws, specifically. But you should be able to use any others that are similar. Additionally you will need one (1) 80mm width acrylic (plexiglass) tube. I used this acrylic tube specifically. 

Print the bottom, the top, and the lid. Use epoxy, silicone, or acrylic sealant to glue the acrylic tube into the center of bottom part. Make sure you apply enough to fill the space to avoid water getting in and to ensure a strong hold. You might also be able to get away with using a strong superglue but I personally have not tried it. Then glue the roof part onto the top of the acrylic tube. Screw the lid onto the top and rest something heavy on top for a few hours and wait for the glue/epoxy/sealant to fully dry before trying to use the bird feeder. 

The suction cups screws will thread directly into the four holes on the back of the bird feeder. It is a little tight on purpose so don't be afraid to push them in and turn them with a little force to get them all the way in.

Print using ABS or ASA. Personally I've had the best results with Polymaker's ASA but you should be able to use any other brand. PETG or Nylon is also a valid option. Do not use PLA because it will deform and wither in the sun and rain. Lastly, I recommend you print it in either blue, red, or green. Data seem to indicate that birds are most attracted to those colors: