Look what I discovered this afternoon! Both flew in, and by the time I got there, the female was sitting sedately above the hollow, and I could hear chipping noises from within hollow - I assume male chewing inside hollow. Male came out, female went in immediately, stayed around mouth of hollow, then into hollow. I don't know whether I heard feeding, or whether it was the superbs close by . . . I think this 'crest-challenged' male, with a battered face, is the same male as sighting #4418003. (and comes after this hollow being disturbed by cockatoos some weeks ago).