I have rosellas (eastern) nesting in a nesting box this morning the male seemed to be calling a lot and there was no sign of the female, I checked the box and there were 3 chicks in it. Just want advise on what to do if she doesn’t return, what to feed the chicks (very young) etc. they nested there last year and disappeared abruptly, I waited a few days before checking and there were 3 dead chicks (more mature) in there