Abstract
The 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.
We 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.
During 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.
Contrary 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.
Overall, 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.
Synthesis and application: Our results point out that low-intensity agro-pastoral land-uses can supplement, but not replace, protected areas in conservation of Thar desert’s 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.
Competing Interest Statement
The authors have declared no competing interest.
Footnotes
Article impact statement: Rangelands and crop fallows can supplement protected grasslands in conserving avifauna of an arid Indian dryland
Data availability: Upon acceptance, the data would be stored in an open-source online repository (either Dryad or Figshare). All the codes would be archived on Github repository.