Keep watch for signs that a bird is being hassled and picked by its cage mates. The lower back is a common picking site. Move any picked ones to a new cage, either separate or with other picked chicks.
Carefully examine the space between the last gray wire (far left) and the brown side of the cage (far right). Note how not only is the air space narrow but the width of the air space decreases on its way down until it is more narrow than the width of a bird band. Birds can get their band caught in the upper wider region and struggle toward the bottom where they are totally stuck.
Insert packing in the air space to protect the birds from getting trapped. I cut strips of padded foam and lodge it in the space between the last wire and cage side. Even cardboard would work. The packing shown is "griprite", a non-slip liner purchased in a roll for $2 at the Dollar General Store!
Providing a Safe and Hassle-Free Cage
Take a critical look at your young birds especially their lower backs for any signs of picking. If so, decrease the animal protein in their diet and move any picked birds to their own separate cage. Also be sure and move any thin birds away from the others as they are high risk for picking and going light. Likewise separate female birds from the more aggressive male birds.
In addition, free your cages from any potential unsafe conditions. It is a terrible tragedy when a bird is accidentally trapped in its cage and breaks it leg. Sometimes this can be a wire sticking out that somehow that manages to slip under the bird's band, trapping the bird. The bird will fight for freedom and in the process breaks or severs its leg.
Or like the example above, the space between the side wire and solid cage side is narrow but not so narrow that a bird's band can't get lodged in the air space. To make matters worse the air space decreases as you look toward the bottom of the cage so that as the bird struggles and moves toward the cage bottom, the narrowing space will more firmly secure the lodged band. And just like the wire accident, the caught bird struggles to get free and in the process will break and sever its leg. Unless seen before the break, the bird will unfortunately loose its leg.
A few years ago, I bought a large expensive name brand four tier floor to ceiling cage. Yesterday, as I was taking care of my birds, I noticed a flutter at the door area of the bottom cage. To my shock, a bird had its nail caught where the wire met the cage door. Luckily, I was able to free this bird without a dislocation or break but what if I had not seen the bird in time?