Out of the Box? Crazy? Down right ridiculous? maye not.
I personally think the struture looks alot like the structure of a bird. the skulls are somewhat simular, the arms are almost like wings, and the fact they actuallly communicate using vocal sounds are all small things leading to the possibillity of a bird. plus, we have the fact that Howard Phillips released his birds in the sprawl, free to go anywhere.
of course, we also run into many promblems. one of the most notable ones is the fact that stalkers are much larger than many birds, and it seems unlikley that people aboard the sprawl took to keeping ostriches and flamingos as pets. (but hey, you never know :D) and it seems unlikely, even if the infection was as materialistic as possibel, that a parrot would be bigger than a dog.
Give me an opinion!