I was birding at Ho Chung today and this bird flew over at 10.25am. I took two or three grab shots. I am assuming it is a) a pratincole - very tern like in flight and for size comparison there were 3 Crested goshawks flying very close by and b) Oriental [pratincole] but I'd appreciate others views. The silhouettes don't show a lot. It was a good day at Ho Chung and I'll post a tick list later.