A study led by Dr Sayam Chowdhury of our Conservation Science Group, draws on more than 14 years of shorebird monitoring in Bangladesh, combined with satellite tracking across Asia, to offer important insights into the decline of migratory shorebird species.
This research began with a simple but urgent question – why are some species collapsing while others remain stable?
Migration is a vital survival strategy for many species, but human-driven disruption of their routes and stopovers has placed migratory shorebirds at high risk of extinction, particularly in Asia.
Bangladesh is a critical region for shorebird migration, because of its position at the crossroads of the Central Asian and East Asian-Australasian Flyways. For more than 14 years, researchers in Bangladesh have carried out one of Asia’s longest continuous shorebird monitoring programmes at Sonadia Island – a globally important wintering site for the Critically Endangered Spoon-billed Sandpiper.
By combining this rare long-term dataset with satellite tracking across Asia, the new study reveals that not all migratory shorebirds are declining equally: species that rely heavily on coastal stopover habitats are disappearing much faster than those using inland wetlands.
12 out of 20 shorebird species studied experienced population declines in 2009–2023. Birds that rely on coastal habitats (e.g. Spoon-billed Sandpiper) showed the largest decreases. In contrast, those use inland stopover habitats (e.g. Tibetan Sand Plover) exhibited stable or increasing trends.
The study’s findings emphasise the critical importance of previously overlooked inland stopover sites, particularly in the Qinghai-Tibet plateau, where 64% of sites used by tracked birds are unprotected.
In examining why some species decline more than others, this research reveals that, if we are to prevent further declines of migratory shorebirds, we must protect both Asia’s vanishing tidal flats and poorly monitored inland stopover sites.
Read more: Sayam U. Chowdhury, Mohammod Foysal, Nazim Uddin Khan, Chi-Yeung Choi, Wangwang Qiu, Daniel J. Field, Nigel Clark, Rhys E. Green, Andrew Balmford; Interspecific variation in shorebird population trends in relation to migration stopover habitat. Proc Biol Sci 1 May 2026; 293 (2071): 20260161. https://doi.org/10.1098/rspb.2026.0161
Find out more about Sayam's work.
Image: Indian skimmers fly past cattle in wetland in Bangladesh. Photo by Sayam Chowdhury.