The critically endangered White-bellied Heron (Ardea insignis) is a piscivorous visual forager that prefers to forage in fast-flowing freshwater rivers. This study highlights White-bellied Heron foraging behavior in the fast-flowing rivers of Namdapha Tiger Reserve during 2013–2017. The herons spent significantly more time and also made more foraging attempts while foraging in shallow water (foraging time: 61.45 ± 15.55%; strike rate: 1.70 strikes/hr). Herons were more successful in catching fishes when they foraged facing upstream (capture rate: 0.62 fishes caught/hr) with increased capture efficiency (44.62%). White-bellied Herons caught the majority (60.98%) of small sized fishes (≤ 9 cm) while facing upstream and the majority (60.92%) of large sized fishes (> 18 cm) while facing downstream. These findings shed light on the manner in which this rare and critically endangered bird is adapted to life on fast-flowing rivers and the importance of these unique places for its conservation.