This gourd-inspired birdhouse is intended for wrens, but it may be a bit snug -- it scaled down slightly for "max build size" on the Rep 2.It was designed using Sketchup. As I am still new to CAD-- it is still much easier for me to grow a gourds than it is to design and print them!

Made on a Replicator 2.
Makerware "medium quality"
.27mm layer height, 2 shells, 20% infill.
Choose colors and switch filament to your liking during the print to make your own multi-color-gourd-birdhouse.