Yes, both Great Knot. Both flagged in western Australia (yellow flag). These are excellent observations - I have been looking unsuccessfully for colour ringed birds passing through Hong Kong.
A couple of minor comments on the ring combinations:
Bird 1. I think the left leg combination is actually Yellow, Red, Green. I realise the green is not very obvious on this bird, but I think that is due to the light. It is also important to note that this is a yellow flag, not a colour ring (also very important to note that this is on the lower leg). This bird is part of an ongoing study in Australia and China looking into refuelling behaviour by Great Knot, Red Knot and Bar-tailed Godwit.
Bird 2. I think the Australian combinations only use letters, not numbers. I think the combination on this bird is UZD, but it's not too clear due to distance (and possibly also the flag has faded slightly).
It is worth reporting both birds to the Australian Wader Study Group, who will be able to provide more information on when/where these birds were ringed (and resighted).
