Imported all parts into FreeCAD and converted the meshes of head and tail to solids, so that they can be edited again.
The head got holes for the leds, the tail got a slot for sliding in the solar cell.
When printed at 43% size, the eyes fit for 5mm leds and the tail accommodates a solar cell 22mm x 56mm x 3mm. The crow is then 20cm from head to tail.
The cut parts are best printed without top and bottom layers and with concentric infill.
The infill can be removed with a pair of sharp pliers to make room for electronics and cables. The switch and charger socked are located behind the legs. I did not prepare holes in the body part for that, I cut them afterwards. Well....
Ehe electronics was taken from an inexpensive lamp, featuring a solar cell, battery, switch, and usb charger. The original white led was substituted for two ultrabright red leds. The original led resistor was 50 ohms, changed to 150 ohm for longer life.
All credits for the superb model go to http://whttp://www.thingiverse.com/danman/designs
-- thank you!
If it were not already cut in the 4 body parts, I'd have used https://github.com/fablabnbg/tinyboy/blob/master/stlcut.py for this.