one nest box to 40 birds ????? that isn't even right. nor is it healthy
the only thing i can come up with was more then one female used this nest box at the same time, and the "lutino" was NOT this pairs baby, Not all birds will willing take on another birds baby (just like not all cats and dogs will foster other cats/dogs babies)
do you know how old these birds are? They may have already been bred enough for their lifetime,
I didn't know it until I asked on here Tiels aren't supposed to breed past age 11 I think it was, and one of my tiels was 22 (wasn't supposed to live that long either), I didn't set them up at first to breed he picked his female and they went to town with NO nest box ( i have this problem with my tiels and budgies, NO nest box for them Nothing in their cage to resemble "nesting" yet they do their business any where and ever where they do not even care who see's them
my breeding birds are together in the same room but each in their own cage! I do have single budgies out and about all day, who can fit into the tiels cage - but my tiels don't care about them they ignore them or beg them for head scratches
but my tiels and budgies like eachother, they get along they prefer to be together If I remove one (say for instance a budgie) the tiels will call for until the budgie is brought back and Vise versa