Wetlands birds in the transboundary floodplains of north-western Bangladesh and their conservation urgency

Abstract

In perspective of the conservation of biodiversity in Bangladesh, transboundary river floodplains are ecologically important but those are beyond protected landscapes particularly in the western part of Bangladesh. The present study was conducted on bird community structure, habitat associations, seasonal dynamics, and conservation issues during July 2020 to June 2022 using direct field observations methods at urban, rural and beel ecosystems of the Chapainawabganj district- a transboundary floodplain of northwestern Bangladesh. Within a comparatively small floodplain landscape, 5,243 individuals representing 172 bird species, 57 families, and 17 orders were recorded, making up nearly 25% of the country's avifauna. Estimators of species richness predicted that the sampling for data collection was about more than 90%. Beel habitats had the highest species diversity and abundance, according to habitat-based analyses (H = 4.154, Ds = 0.975). This habitat comprises mudflats, shallow water bodies, and surrounding vegetation where 93.6% of the documented species appeared during the winter, including 66 migratory species. The conservation value of the area was highlighted by the documentation of nationally threatened species, including Clanga hastata (EN) and Mycteria leucocephala (CR). Anthropogenic pressures, such as hunting, agricultural netting, wetland conversion, pollution, and growing urbanization have been increased on the floodplain ecosystem, despite its high biodiversity value. The present study shows that unprotected transboundary wetlands significantly contribute to regional ecological connectivity and serve as vital refugia for migratory and resident birds.

Dhaka Univ. J. Biol. Sci. 35(2), 19-38, 2026 (July)