Riverine Waterbirds and Sites

Riverine Waterbirds & Sites

Key species

Riverine birds

Location

Large Rivers of Bangladesh

Status

Completed

Duration

2011–2015

Target community

Policy | Science

About the project

Bangladesh’s major river systems, particularly the Padma and Jamuna, support highly dynamic sandbars (chars), mid-channel islands, floodplain wetlands and riverine grasslands that together form one of the country’s most important yet under-recognised ecosystems. These shifting landscapes provide breeding, roosting and foraging habitat for migratory and resident waterbirds, including globally threatened species such as the Endangered Black-bellied Tern and Indian Skimmer. At the same time, tall floodplain grasslands dominated by Saccharum support grassland-dependent species such as the Vulnerable Bristled Grassbird, highlighting the ecological connectivity between river channels and adjacent grassland habitats. Despite their high biodiversity value, riverine ecosystems have historically received limited formal protection. Conservation efforts in Bangladesh have largely focused on forests, mangroves and wetlands, while dynamic river channels, sandbars and associated grasslands remain underrepresented in the protected area network. As a result, critical breeding sites and riverine grasslands continue to face increasing pressure from land conversion, disturbance and habitat alteration, underscoring the need for systematic identification and site-based protection.

The problem

– key riverine waterbird breeding sites and floodplain grasslands remain unprotected

– globally threatened waterbirds and grassland species depend on highly vulnerable, dynamic habitats

– increasing human disturbance, land conversion and habitat degradation threaten riverine biodiversity

The cause

– lack of systematic surveys identifying priority riverine and grassland sites

– limited integration of dynamic river ecosystems into protected area planning

– insufficient recognition of sandbars and floodplain grasslands as conservation priorities

The solution

– survey major river systems to locate breeding colonies, congregation sites and priority grasslands

– assess ecological characteristics and site-level threats

– provide scientific justification for protected area designation

Project Goal

To identify, document and promote the protection of nationally and globally important riverine waterbird and grassland habitats in Bangladesh.

Project Objectives

– survey major river systems to locate breeding colonies, congregation sites and priority grasslands

– assess ecological characteristics and site-level threats

– provide scientific justification for protected area designation

Riverine bird survey – Padma River | Kushtia | Bangladesh 2013

Activities

Systematic surveys are conducted along major river channels and adjacent floodplain grasslands to document breeding colonies, roosting sites and grassland-dependent species. Standardised counts and distance sampling methods are used to estimate population size, particularly for grassland specialists such as Bristled Grassbird. Habitat variables, including vegetation structure and disturbance intensity, are recorded to understand species – habitat associations.

Remote sensing and spatial analysis are used to map sandbars, river channels and Saccharum-dominated grasslands, identify newly emerged habitats, and delineate ecologically significant landscapes. Site-specific threats such as grazing, sand extraction, cultivation and human disturbance are assessed. Scientific findings and maps are then compiled into formal proposals for submission to relevant authorities to support protected area designation.

Projected potential distribution (black areas) of Bristled Grassbird in the Padma and Jamuna river systems in Bangladesh based on habitat suitability model (ISO Cluster classification), study sites (red squares) and point count stations of site 1 (white circles).

Outcomes

The project has identified previously under-recognised riverine breeding sites and grassland strongholds supporting globally threatened species. It has generated the scientific evidence necessary to advocate for legal protection of priority riverine landscapes. The work strengthens national recognition of river channels, sandbars and floodplain grasslands as critical ecosystems and contributes to expanding Bangladesh’s protected area network to include dynamic river systems.

Proposed protected area (2522 ha) boundary along Padma River

The proposed riverine landscapes meet key criteria for protected area recognition due to their concentration of priority species and their ecological uniqueness. Surveys have documented breeding populations of resident waterbirds and substantial grassland-dependent bird populations within spatially definable riverine units. These habitats are seasonally predictable and ecologically connected, allowing for feasible boundary demarcation and site-based management. Incorporating these dynamic riverine ecosystems into the protected area framework would address an important ecological gap in Bangladesh’s conservation network and ensure long-term protection of both aquatic and grassland biodiversity.