I've allready noticed that the breeding birds from India have quite a strong bill and can be of really sandy color, but they are very unlikely to occur in HK. Kentish Plover from Middle East also show such charateristic.
What is expected to occur in HK and in Guangdong, as HK appears to be a "No Swinhoe's Plover land", is :
- what is now named as Eastern Kentish Plover or ssp nihonensis from Korea, Japan and very likely Taiwan
- nominate ssp alexandrinus that I guess is not the commonest one
- and then what is currently named dealbatus or Swinhoe's Plover for wich the repartition is poorly known, appart that it is a bird easily found on the Guangdong and Fujian coast in available habitat. It is said in the litterature that dealbatus should breed up to North China, but up to date it is rather unclear to wich subspecies belong the North China birds.
Well actually, I can be so affirmative, because of the moulting stage of this bird that corroborate my personal observation and that at this time of the year let very few chance this bird belong to nihonensis and less to alexandrinus. The bill structure is something quite difficult to appreciate, and very variable in both subspecies. Actually it is more the addition of all this features together that make me believe this bird to be dealbatus rather than nihonensis, there is presumably a slighty overlap in bill size and shape between this two subspecies, but plumage and moulting time is of very good help at this time of the year.
The bird from Stonechat is very likely an other one as well, and could concern a First Winter bird, but I'm less confident because I have very few data concerning 1st W plumage, so I wont be so affirmative, however the strong tubular bill and strong pink leggs are a very good indicator of dealbatus, as well as the paler mantle just after the postbreeding or post juvenil moult.
More information will be release in due date about the different plumage of Swinhoe's Plover.
I also would like to encourage people to post as many picture as possible of the Hong Kong Kentish Plover. Also few birds has been recently flagged in Mai Po, and it would be of great interest to see pictures of them even a bit distant during the following months if the bird may wintering there.
To conclude, dealbatus should be I'm sure of more regular occurence in Hong Kong, but are actually overlooked because of its not very well known plumage. There is actually quite a few other good candidat has been post in this forum in the past. I will mention them in due date as well.
All the best,
Jonathan