Could maturation of forest habitat be leading to dispersal? Or is a reduction of suitable habitat north of HK leading to more movement south plausible? I am surprised that red-billed leothrix is not recorded more on HK island as an established breeding bird. I know silver-eared mesia was on Braemar Hill in the 1990s- obviously another release bird. I can't recall ever seeing leothrix there though. Anecdotally, I would say leothrix is more common in the bird trade.
I have always found red-billed leothrix very hard to actually see, I often suspect they are scrabbling away in the undergrowth out of sight and normally get no more than a glimpse of them through foliage so they are probably under-reported (at least by me!).
Dylan
