Understanding land-use responses of bird communities in an arid ecosystem of India

O_LIThe Indian Thar desert has lost much of its grasslands over the last few decades, mainly due to land-use change from pastoralism to agriculture. Expanding croplands and intensifying grazing pressures are popularly hypothesized to be major drivers of biodiversity loss in the region. Our study aims to investigate the effects of contemporary land-use change on bird communities of the Western Thar Desert. C_LIO_LIWe surveyed 58 randomly laid line transects in a c2000 sq.km study area, to quantify parameters of bird community structure in three predominant land-use types viz. protected grasslands, rangelands, and non-irrigated croplands. Fieldwork for the study was conducted in the dry season (winter and summer) between December 2018 and April 2019. C_LIO_LIDuring winter, overall bird richness and abundance were highest in protected grasslands followed by non-irrigated croplands and rangelands. Protected grasslands also had a higher abundance of diet and habitat specialists. Compared to protected grasslands, density was lower in non-irrigated croplands and rangelands for 35% and 10% of species, respectively. A majority of the negatively affected species were insectivorous grassland specialists. C_LIO_LIContrary to the pattern in winter, overall bird richness, abundance, community composition, and guild structure in summer were similar across three land-use types. Only one of the 17 analysed species had lower density in modified land-use types. C_LIO_LIOverall, protected grassland was the best habitat for birds and was specifically important for specialists, particularly during the winter. Rangelands and fallow croplands sustained most generalists at comparable densities but had severe negative impacts on specialists. C_LIO_LISynthesis and application: Our results point out that low-intensity agro-pastoral land-uses can supplement, but not replace, protected areas in conservation of Thar deserts avifaunal diversity. Our results are consistent with the idea of managing dryland habitats as agro-grassland mosaics with embedded protected areas, in order to reconcile human needs and biodiversity conservation at a landscape scale. C_LI