One of the prominent kingfisher found in the mangrove forest is brown -winged kingfisher in addition to Black capped, collared, white throated, common and pied.
They are highly territorial and does not hesitate in chasing big predators such as eagles. I observed them during my recent visit to Sundarbans Tiger Reserve in the State of West Bengal.
Image taken on 22nd February 2020 at Sundarbans Tiger Reserve.