Here in NE Sichuan - at the moment were on a low mountain range, at the very east of the province, that BOP's seem to use as a thermal catapult on their passage south thus avoiding the flat Sichuan basin and the High Mountains to the West - we're getting the same species as you guys are getting in the NE, Black-eared Kite, Oriental Buzzard (the most common raptor at the moment), Eurasian Sparrowhawk, Kestrel, Hobby and Pied Harrier.
We watched the same area exactly one year ago and got a different set of species - Common Buzzard, Eurasian Sparrowhawk, Grey-faced Buzzard, Black Baza, Kestrel and just one Oriental Honey Buzzard.
Of course we're not getting the numbers that Tom has seen - but it's interesting that just now our most common raptor is also OBH, while a year ago we only saw one bird over a week of being in the area.
It would interesting to learn more about the raptor flight paths over China - and whether any of our birds are those which you guys have been observing in the NE.