Take a milk jug and cut holes on two sides. Poke holes in bottom for rain drainage, one below each large hole and one on each side of top. Put wire through top holes for hanger and a skewer through side holes for perches.
I've got tons of milk jugs! I imagine you could use this idea and add a strap type of handle. Reusable gift bag if you did that. Change up what you cover it with for the purpose, Christmas fabric, Valentines Fabrics, etc.
A beautiful DIY with plastic bottles. Tip: Use a medium hot iron and place it on the mouth of the bottle to connect the finish! Use baking paper between the Iron and the bottle, so you don't ruin the iron!
25 Fantastiche Idee Su Come Riciclare Le Bottiglie Di Plastica + Video tutorial su Bottiglie Forate