Avifaunal Community Assemblages in Transforming Non-Protected Ecosystems: Evidence from Citizen Science Data in Southern West Bengal

Anthropogenic land-use change and habitat fragmentation are primary drivers of global avifaunal declines. In rapidly developing regions like West Bengal, understanding bird community responses in semi-urban and rural mosaics is critical for conservation, yet systematic studies in non-protected landscapes remain limited. This study integrated long-term citizen science data from eBird (2017–2023) with Sentinel-2 satellite imagery to analyse avian diversity, community structure, and habitat associations across the Paschim Medinipur and Jhargram districts. We employed ecological metrics including Shannon-Wiener diversity, NMDS ordination, and PERMANOVA to quantify spatial and seasonal variation in assemblages across seven land-use/land-cover (LULC) classes A total of 344 bird species from 20 orders and 72 families were recorded. Croplands and rangelands emerged as primary biodiversity reservoirs, supporting the highest species richness. Winter was identified as the peak period for diversity, driven by a significant migratory influx. NMDS and ANOSIM analyses revealed pronounced environmental filtering; while generalists increasingly dominated human-modified landscapes, habitat specialists—particularly forest and wetland birds—exhibited high sensitivity and steep turnover rates in response to LULC transitions (R2 ~ 0.76 and 0.67, respectively). Conversely, grassland and scrub specialists showed abundance gains associated with open-habitat expansion. The study underscores a progressive biotic homogenization driven by the conversion of ecologically sensitive ecotones into simplified, human-dominated land covers. While agricultural mosaics currently function as critical refuges, their conservation value is threatened by industrialization and unsustainable practices. We advocate for integrated landscape-scale management that prioritizes forest-cropland ecotones and restores hydrological connectivity to sustain regional biodiversity in transforming peri-urban ecosystems.