We offer bird cages from several manufacturers in different styles and different sizes.
Some styles have bar spacing that wil accommodate every bird from Cockatiels to Macaws. Others are made specifically for one species or birds of similar sizes.
Parakeets, Finches, Canaries require the closest bar spacing at 1/2" between bars.
Cockatiels and cockatiel-sized birds require wire spacing no more than 5/8" between bars. That includes Conures, Lovebirds, Quakers and other Parrotlets.
Macaws can have bars spaced up to 1" apart. Most Cockatoos can also use 1" spacing, although cockatoos are so strong, that the quality of the cage wire is very important.
Amazons are right in the middle. They can utilize cages with bar spacing from 5/8" up to 3/4".