Avian Species Diversity and Population Dynamics in the Aravalli Region of Rewari, Haryana, India

Abstract

The Aravalli Range, one of the oldest mountain systems in the world, supports diverse ecosystems that remain inadequately studied with respect to avian biodiversity. This study presents the first comprehensive systematic assessment of avian species diversity and population dynamics in the Aravalli Region of Rewari district, Haryana, India. Line transect distance sampling was conducted across 12 permanent transects spanning five habitat types (dry deciduous forest, scrubland, agricultural land, grassland, and human settlement) during four seasons over a 12-month period, yielding a total of 192 surveys. A total of 156 bird species belonging to 18 orders and 52 families were documented, with Passeriformes constituting the dominant order at 37.2% of all species recorded. The Shannon-Wiener diversity index reached its maximum value of 3.91 during the post monsoon season, reflecting the influence of seasonal climatic cycles on avian community structure. Dry deciduous forest emerged as the most species-rich habitat, supporting 78 species during the post-monsoon period. Population density estimates generated through distance sampling revealed House Crow (Corvus splendens) as the most abundant species at 22.0 individuals/kmZ. The study also recorded 12 species of conservation concern, including four vulture species classified as Critically Endangered or Endangered by the IUCN. Insectivorous species represented the most diverse feeding guild. These findings establish the Aravalli Region of Rewari as a significant avian diversity hotspot in the semi-arid landscape of northwestern India and underscore the urgent need for targeted conservation strategies to protect its threatened bird populations and fragile habitats.