Feeding is the leading cause of illness among pet parrots. Feeding only seed lack essential vitamins. A balanced diet is built from complete pellets with fresh produce. Certain foods are toxic, including avocado and chocolate.
Companion parrots are a long-term commitment, with larger species living well beyond forty years. The species vary dramatically across their demands. Larger parrots require constant engagement, and compact species are better suited to limited space.
Where you buy matters as much as the bird you pick. Hand-reared Pickin Parrots raised by a good breeder adapt far better to a home. Ask about disease testing as well as the conditions birds are kept in. Legal documentation matters where CITES applies.
Cage and aviary size matters considerably more than most other factors. The bird should be able to stretch fully clear of the bars. Varied perches reduces pressure sores. Toys and foraging opportunities matters as much as space: boredom leads to destructive behaviour.