One of the most common problems in parrot-keeping today is not providing our feathered friends with the size of cage they need. Housing a bird in an undersized cage can lead to all of the worst behavioral problems found in pet birds: screaming, phobic behavior, biting and aggression, and feather plucking. A common misconception is that a cage is a place of confinement. We do not think of a cage as a place of confinement but as a home and comfort zone, similar to the way we view our own homes. This is where the food is kept and where the familiar water bottle hangs. When a parrot is under stress, you will probably notice that he or she is most relieved when returned to it's cage. Pet birds spend a vast majority of their time housed within these four walls.
Just think, if you just take the amount of time you are not at home (when the bird should not be left out of its cage) and add it to the number of hours the bird needs to rest and sleep (at least 12), the average bird will be in its cage at least twenty hours a day and sometimes more. Leaving the bird's door open or not confining a bird at all is extremely dangerous and totally unacceptable. A person is inviting disaster when ignoring this important rule of thumb.
The reasons a bird needs a cage are many. First of all, they need a wide variety of perches to keep their legs and feet properly exercised. They need different textures as well as diferent diameters. It is very difficult to provide a bird with adequate perches on a playpen. Even if you are able to provide them, the parrot will spend the vast majority of its time on the highest perch. When the bird is in its cage, it is more secure and comfortable and will use all of its perches at some point in the course of a day, not just the highest one. At the very least your bird will play with different toys and venture to its food and water sources. Also, when the bird is on the top perch of a playpen, where are the toys hanging? You could tie one to a rope connected to the high perch but it tends to get pooped on, and even then it is only one toy. They need a variety of toys just like they need a variety of perches.
For the sake of argument, let's assume the parrot had all the proper perches and toys in a playpen setting and actually used them. It's not completely unheard of, but it begs the question: Where is the bird getting its water? All parrots should be drinking from water bottles, not water bowls, and I have yet to see a playpen with an apparatus to support a drinking bottle. If you would like more information on water bottles, Dr. Greg has written an article that can be found here. The point is, it is impossible to provide a pet bird with a proper, safe, and comfortable living environment without a cage. The most obvious consideration when selecting a cage is the size of the bird. Parrots need to be able to flap their wings and stretch them out to full wingspan.
A factor that often gets overlooked when looking at cages is that these cages will be occupied by not only the parrot but also food bowls, three to four perches, at least three toys and with whatever else the owner decides to spoil the bird. These objects, while absolutely necessary, dramatically cut down the amount of open space in the cage. Another important determinant is the bird's activity level. You will notice some discrepancies between birds and the size of the cage required. A good example is a parrotlet. If you have ever spent time around parrotlets, you know that they rarely stop to catch their breath. They are very playful and are rarely in a state of rest. For these reasons, they need a larger sized cage than the slightly larger budgie that has only a moderate activity level.
Round cages cannot be used. They do not give your pet a point of reference and will can lead psychological problems. Also, the vast majority of commercial parrot products are not made to attach to a curved surface. If you are having any problems with your parrot, look closely at its cage size. This is often the root of many different problems. If you currently have a cage that is too small, use the suggestions below as guidelines and you will be on your way to an improved relationship with your pet bird!
Minimum Cage Size and Maximum Bar Spacing:
If your bird was not listed, find one of similar size and use that as a base but be sure to take into account the activity level of the species.