Recordings of Black-winged Cuckoo-shrike can be found on xeno-canto Asia
http://www.xeno-canto.org/asia/b ... racina+melaschistos
These fit fairly well with the recording of the Po Toi bird: a descending sequence of three clear notes. It also fits with the descriptions of the call I have seen (including, in my opinion, the Robson description). I have not heard the species in China (or anywhere!) so cannot comment on Richard's recording.
As seems to be general opinion, I think the bird must be Black-winged Cuckooshrike, probably either the SE Asian (
saturata) or Indian (
melaschistos) subspecies, which are apparently both dark. Like the two Mikes, I think there is evidence of feather damage (an obvious missing primary, probably also damage to the tail and body feathers) which must cast doubt on the origin of the bird.
