The right cage size depends on your bird's species, wingspan, and activity level. A universal rule is that the cage should be wide enough for the bird to fully extend both wings without touching the sides, and long enough to allow short flights or at least vigorous flapping. Longer horizontal cages are generally better than tall narrow ones, since birds fly horizontally rather than vertically.

For small birds like budgies and finches, a minimum cage size of 18 by 18 by 18 inches is recommended for a single bird, though larger is always better. Cockatiels do well in cages at least 24 by 18 by 24 inches. Medium parrots such as conures and Senegal parrots need at least 24 by 24 by 30 inches. Large parrots like African greys and Amazons require a minimum of 36 by 24 by 48 inches, and macaws or cockatoos need the largest enclosures available, ideally walk-in aviaries or cages at least 48 by 36 by 60 inches.

Bar spacing is equally important and often overlooked. Small birds need bars spaced no more than half an inch apart to prevent head entrapment. Medium birds do well with five-eighths to three-quarter inch spacing. Large parrots need bars spaced three-quarters to one and a half inches apart, with thicker gauge wire to withstand their beak strength.

Choose a cage made from powder-coated steel or stainless steel. Avoid zinc-coated, lead-soldered, or brass cages, as these metals are toxic when chewed. The cage should have a secure latch that your bird cannot open, a removable grate and tray for easy cleaning, and multiple door openings for perch and dish placement.

Remember that even a spacious cage needs daily supervised out-of-cage time for exercise and socialization.