Anyone figured why Mai Po is closed due to bird flu - other than as birds make convenient scapegoats and closure politically easy while seems to be taking action?
Anyway, I've made recent trips to Tsim Bei Tsui, on Deep Bay west of Mai Po. Don't need a permit (unlike Mai Po even when open), many of same birds, tho viewing less convenient.
Get out past Lau Fau Shan, to end of Mong Tseng Peninsula: probably the most convenient way by public transport is by taxi from Yuen Long (ask for Lau Fau Shan, turn right at roundabout there, along narrow road to ne).
From here, you can then look out over Deep Bay (loads of ducks; peering hard thro scope, even seen Dalmatian Pelican on mud in front of Mai Po, also osprey, great crested grebes).
Then, walk down and along road by mangroves. Can peer thro border fence at one place, see some birds of mudflats; can also check ponds on right - maybe best with fairly high tide (check via observatory website).
Birds here lately inc 4 species kingfisher, plenty of egrets, kites, a pretty close black-faced spoonbill (others further away in the bay), even an eagle owl late one afternoon.
Ideally, need binoculars and telescope to see birds well; if you lack, can still wander around, see egrets etc, and see the area.
Just before car park at tip of peninsula is a turning circle (mini roundabout); minibuses come here - you can catch one back to Yuen Long. (ask if you want to take West Rail from there to Mei Foo in Kowloon - I think the best station for this is before Yuen Long [I wound up at minibus end stop in YL, had to walk a v few hundred metres to a station])
On Sundays, can get a bit busy with local "eco-tours", which have nothing to do with eco-tours as rest of world knows them (folk on buses like sardines, wander around with little or no guidance)