Large crested BIRDS in the family Cacatuidae, found in Australia, New Guinea, and islands adjacent to the Philippines. The cockatiel (species Nymphicus hollandicus) is much smaller.

Diseases of birds not considered poultry, therefore usually found in zoos, parks, and the wild. The concept is differentiated from POULTRY DISEASES which is for birds raised as a source of meat or eggs for human consumption, and usually found in barnyards, hatcheries, etc.

BIRDS of the large family Psittacidae, widely distributed in tropical regions and having a distinctive stout, curved hooked bill. The family includes LOVEBIRDS; AMAZON PARROTS; conures; PARAKEETS; and many other kinds of parrots.

Virus diseases caused by the CIRCOVIRIDAE.