Guwahati: Climate change could steadily shrink the already fragile habitat of Jerdon’s Babbler, one of the Brahmaputra Valley’s rarest grassland birds, with rising temperatures and changing floodplain conditions threatening to push the species into deeper ecological isolation, a new study has warned.
Researchers found that only small pockets of Assam and Arunachal Pradesh currently remain highly suitable for the Vulnerable bird, which depends almost entirely on the tall riverine grasslands shaped by the Brahmaputra’s flood cycles.
Published in The Science of Nature, the study used climate and habitat modelling to predict how the bird’s range could change by the 2060s under different warming scenarios.
The research was conducted by Chiranjib Bora, Vivek Chetry, Nilutpal Mahanta, Prasanta Kumar Saikia and Malabika Kakati Saikia, using field data from Kaziranga National Park, Manas National Park, Dibru-Saikhowa National Park and the Maguri-Motapung Important Bird Area.
The findings paint a worrying picture for a species already surviving within a narrow ecological range.
According to the study, only around 6,498 square kilometres currently qualify as “Excellent” habitat for the bird, while 8,362 square kilometres are considered “Highly Suitable.” After accounting for land-use change, habitat alteration and human disturbance, the area of prime habitat declines further to just 4,837 square kilometres.
In contrast, more than 121,000 square kilometres of the broader landscape is already considered unsuitable for the species.
Researchers initially compiled over 300 occurrence records gathered through field surveys, published literature and the eBird database. However, after removing duplicate and overlapping data, only 65 reliable occurrence points remained for modelling, highlighting how rarely the bird is encountered even within its known range.
The study identified annual mean temperature, rainfall and elevation as the most important factors influencing the bird’s survival. Researchers also found that rising maximum temperatures during the warmest months are likely to become increasingly critical in future decades, raising concerns about heat stress during breeding and feeding periods.
Unlike more adaptable bird species, Jerdon’s Babbler relies on dense alluvial grasslands constantly reshaped by flooding, erosion and sediment movement across the Brahmaputra basin.
The researchers warned that climate change could further destabilise these already fragile ecosystems by altering rainfall patterns, drying out vegetation and intensifying habitat fragmentation. Reduced rainfall and rising temperatures could lower grass productivity, affecting both nesting cover and insect prey availability.
Under a high-emission climate scenario projected for the 2060s, the area classified as “Excellent” habitat declines further, suggesting that warming could steadily erode the bird’s remaining strongholds.
The authors said the findings reflect a wider conservation crisis unfolding across the Brahmaputra floodplains, one of South Asia’s least protected yet biologically unique ecosystems.
While forests in Northeast India often receive greater conservation focus, the study noted that floodplain grasslands remain overlooked despite supporting highly specialised and range-restricted wildlife.
The researchers called for urgent habitat restoration, ecological corridors linking fragmented grasslands, expansion of protected areas in climatically stable zones, and long-term monitoring of both the species and its habitat.
The study adds to growing evidence that climate change is becoming a major threat not only to Himalayan forests but also to the dynamic grassland ecosystems of the Brahmaputra Valley.
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