The Paradox of Shorebird Diversity and Abundance in the West Coast and East Coast of India: A Comparative Analysis

Abstract

Migratory shorebirds that move across continents along their flyways are undergoing a drastic decline globally. A greater proportion of them that regularly winter along the Indian coasts within the Central Asian Flyway (CAF) are also undergoing severe declines. However, the mechanisms underlying the population trends in these areas remain little understood. This study investigated the diversity, abundance, population dynamics and distribution patterns of shorebirds along the Indian coasts based on the available literature. The west coast of India is relatively less studied than the east coast in the CAF. Further, we observed that the diversity, abundance, population dynamics and distribution pattern of the shorebirds follow different trends on the west coast compared to the east coast. These variations are in accordance with the differences in topography and biotic and abiotic factors between the coasts. Anthropogenic activities have far-reaching effects on the survival and persistence of shorebirds along the coasts. The west coast is evidently more productive than the east coast at every trophic level and thus the west coast is expected to account for more abundance and diversity of shorebirds. Paradoxically, we found that the east coast supports a greater abundance and diversity of shorebirds than the west coast. The west coast, therefore, requires further investigations to obtain a better understanding of the causes of apparent differences in abundance and diversity as well as the observed declines in shorebirds, compared to the east coast of India.

From the Arabian Peninsula to Indian shores: Crab Plover Dromas ardeola Paykull, 1805 (Aves: Charadriiformes: Dromadidae) breeding at Point Calimere, India

“…Last, as only the eastern tip of the GVS is protected by the Point Calimere Wildlife Sanctuary, the largest part of the insular and intertidal ecosystems of the GVS is threatened by hunting, by the development of salt pans and prawn farms, and by the spread of invasive species like Prosopis juliflora. The result is a significant decrease in avian species diversity and abundance compared to historical records (Rashiba et al 2022).…”

Temporal variations of shorebird (Charadriiformes) community and its diversity at Muttukadu backwaters - a wintering site in the southeast coast of India

“…The abundance, diversity, population dynamics of shorebirds are higher in east coast than west coast of India (Rashiba et al 2022). But earlier studies by Balachandran (2006) and Sandilyan et al…”

Avifaunal Diversity and Abundance in the Proposed Sarasalai Mangrove Reserve, Jaffna, Sri Lanka

“…Hence, it is obvious that these sensitive ecological conditions are playing a critical factor in the continuation of migrant birds in the proposed Sarasalai mangrove. However, the winter migrant population in the traditional wetlands in the last three decades is dwindling [42,47]. Among the major threats attributed to the sustainability of these wetlands is human disturbances [42].…”