The first wintering adult BFS usually arrive in mid-October. Some young BFS could stay in HK over the summer and so their appearance may lead you to think the BFS have returned. But I just haven't seen any young BFS for more than two months (if any member saw it in this summer, please correct me!), any BFS present at Mai Po or other places in Deep Bay from now could be the wintering individuals.
Thank you very much
[ Last edited by yyattung at 27/09/2010 11:59 ]