This is the same species as Madcat's bird - Black-faced Bunting as lchunfai noted. Female/immature Black-faced Buntings tend to be rather dull buntings. The most conspicuous feature (as shown in both photographs) is the whitish submoustachal stripe. This seems to be the only bunting species on Po Toi right now.
It's still a little early for Yellow-breasted and Chestnut Bunting and I believe that Yellow-breasted Bunting is pretty rare on Po Toi, especially in spring.
david
