Parakeet mutations ahoy!
To quote
Wiki:
The Budgerigar (Melopsittacus undulatus, nicknamed budgie), the only species in the Australian genus Melopsittacus, is a small parrot belonging to the tribe of the broad-tailed parrots (Platycercini); these are sometimes considered a subfamily (Platycercinae). In the latter case, the Budgerigar is sometimes isolated in a tribe of its own, the Melopsittacini, although it is probably quite closely related to Pezoporus and Neophema. Though Budgerigars are often called Parakeets, especially in American English, this term refers to any of a number of small Parrots with long flat tails. The Budgerigar is found throughout the drier parts of Australia and has survived in the inlands of that continent for over 5 million years.
The little guys usually look like this healthy young male:
Wild budgies are blue or green. As they were domesticated and bred for the pet trade, some interesting feather combinations began to happen. Pet-bred budgies are often inbred, with rather sad results. Inbred pet budgies have extremely high rates of tumors between the ages 5-7. I don't know if these mutated budgies were inbred, but I can promise you that most of this never happens in the wild.
Feater Duster mutation:
Albino variety:
Lutino variety: (The eyes look weird, but I think it's just the camera)
There's a million different
colour combinations that I won't get into...
Oh, and there's these guys, a mutation that is now it's own class of budgies: English budgies (or Standard-Type). They look rather serious.
Very serious:
You can find more pictures of mutated parakeets and parrots
here, although the pictures are of low quality.