Recently participated in the English language Mangrove Boardwalk Adventure tour run by the WWF at the Mai Po Nature Reserve and had another very good experience birdwatching and spending time out in nature.
This tour was rescheduled a couple times due to the 5th wave which shut down pretty much all events throughout the city over the past few months. There were only 4 participants this time around, the tour leader, Walter, did a very good job of explaining some of the history of the area, the role of the WWF and the founding of the Mai Po Nature Reserve, an important year round ecosystem and migration stopping ground for tens of thousands of birds during the cooler winter months.
Visiting during May meant seeing far fewer numbers of birds and some species that are around earlier in the year having cleared out, returning home. We did see a few groups of black-faced spoonbills and other interesting birds including wagtails, turns, avocets, sandpipers, whimbrel, curlew, common redshank (one on a nest which is supposedly very rare at Mai Po), grebe, heron, loads of egrets (several cattle egrets only seen here now that they have two resident buffalo), coucals, magpies and others. There were quite a few butterflies, moths and loads of dragonflies on this occasion.
One of the neat features of the Mangrove Boardwalk adventure is that they take you into the restricted Deep Bay mangrove area, where you walk across floating boardwalk for around 10 minutes until reaching hides deep into the bay. The birdwatching was excellent here while the tide was low. Many of the birds flew back into the gei wei ponds closer inshore as the tide began to rise. Walter took us back to a couple hides closer inland where we saw many more birds.
The tour is around 5 hours in length from pick-up to drop-ff in Yuen Long and you have around 4 hours of actual birdwatching. Most tours are in Cantonese but you can join them as well, even if you don't speak the language. The guide will explain things to you on the side after addressing the rest of the group in Cantonese. We've done this before, it is just fine. Otherwise, they run several English language tours which are better suited to English speaking visitors. You can book these tours rather simply through the WWF Hong Kong website. For winter tours when the migratory birds are in the area, best to book the English language tours a month or more in advance as they are popular.
Note: You can rent binoculars from the WWF (presently HK$20 per person). If you have a quality pair, bring them. The birds are expediently at great distances away much of the time, you'll need them to see the birds well.