Regardless you are a Salim Ali fan or not, bird watching during winter in Sundarban is a pleasure for your eyes. The area attracts lots of fish catcher birds, but some migratory birds are available to watch and enjoy during winter. Some of the most popular bird species are available here are Lesser Whistling Duck, Black-Capped Kingfisher, White Breasted Kingfisher, Collared Kingfisher, Black Hooded Oriole, etc.
There are some more attractions in the list of beautiful birds you can watch here. The names are Common Kingfisher, Small Minivet, Pariah Kites, Herring Gulls, Brahminy Kites, Marsh Harriers, Swamp Partridges, Cotton Teals, Caspian Terns, Gray Herons, Brahminy Ducks, Spotted Billed Pelicans, Night Herons, Common Snipes, Wood Sandpipers, Green Pigeons, Open Billed Storks, Paradise Flycatchers, Fishing Eagles, White Bellied Sea Eagles, Seagulls, Peregrine falcons, etc.
Also, you may find Woodpeckers (multiple varieties), Whimbrels, Black-Tailed Godwits, Little Stints, Eastern Knots, Curlews, Golden Plovers, Pintails, White-Eyed Pochards, and Whistling Teals, which are a few beautiful birds you can watch during the trip.