Was the little guy weaned at just 6 weeks? I’m a bit concerned about his development, when you say he is still clumsy. If he was just clumsy being in the cage for the first time, that is pretty normal. Usually the green cheeks wean closer to 12 weeks, and that’s mainly because they get force-weaned. In the wild they would still get fed longer by the parents while they learn to forage. So I just want to make sure your little guy received the extra nutrition that he needed during this time.
As for sleeping in a box, it’s OK for another couple of weeks or so. If you bought him a large cage, you might want to buy a smaller starter cage. This can later be used for transport, such as to the Vet. Young birds are generally not ready for their large cage yet. But if you can’t get a starter cage, the first thing to do is put something on the metal grate in his cage – paper towels or brown paper works well. A towel isn’t the best choice since he can get his nails caught. Put his box in the cage and let him explore from there. You might cover half of the cage to make it feel smaller at first. When he is used to the cage, and more confident, then you can wean him off sleeping in the box. He would soon be driven from the nest area or the family would move. Once he is self feeding and able to forage on his own, he will no longer be allowed in the nest, and will soon be made to leave his parents. This prevents in-breeding in the wild. You can have a gentler approach, but don’t let him be dependent on the box for too long. I know they sell bird tents and huts and little houses, but these are not good items for weaned birds. And actually the huts, tents and anything made from a soft fiber are not recommended for the green cheek conures. While a study has not been done, some Avian Vets have seen a lot of this species that have ingested the fibers for some reason. Most have not survived. It isn’t understood why this particular species does this more than others, or possibly just because they are so popular and love getting in things, there are more diagnosed because there are more of this species. But meanwhile, you don’t want your little guy to be added to the statistics. So back to his box – the cardboard and Aspen are fine – aspen is the only safe type of shaving for birds. But as he gets older, the box can trigger his hormones and can lead to behavior and health issues. So it’s best to have a goal for him to learn to sleep on a perch when he is steady enough. He won’t be excited to see his box go, but we have to do a lot of things they don’t like, for their own good. You can hang some toys by a high perch, and this can mimic the cover the leaves on a tree would give him. He will do fine – just take it slow and be consistent with him.
Thank you for asking Lafeber,