Several young Black-faced Spoonbills were fitted with transmitter for satellite-tracking of their migration route in 2009 and 2010. Some details are shown in the this link:
https://sites.google.com/a/conservationecology.asia/en/home/tracking-bfsb
Comparing to the previous satellite-tracking study which were made with catching birds from wintering grounds (in both Hong Kong and Taiwan), this is the first study to focus on the Black-faced Spoonbill's southward migration and only young birds could be caught and fitted with the transmitter. It also gives us interesting results. Two of the five young BFS moved to places where the other BFS would not usually go, one going into lower Yangtze River plain and another going to the southern coast of Vietnam (now! just yesterday). Both places have records of the BFS before but not regularly. This result also show that young BFS has a higher tendency to go away from the 'traditional' wintering grounds, perhaps they lack of experience of these traditional wintering grounds.
The bird going to Vietnam actually migrated through the East China coast in 7 days (from 4 to 10 November 2010), an interesting information of how fast they can do the migration. It flied close to HK in the southeast waters but not going to Mai Po. (Geoff: it is possible that one day you can see BFS from Po Toi!) It is also out of my expectation that the bird seems to migrate through the east coast of Hainan Island and then across the western part of South China Sea to southern Vietnam. I expect it would go along the south China coast to Red River Delta and then along the Vietnamese coast to the south. This bird may go further down to Thailand because there are regular winter records of young BFS in the Gulf of Thailand.