Monitoring observations of the southernmost breeding population of Long-billed Vultures Gyps indicus (Scopoli, 1786) (Aves: Acciptriformes: Accipitridae) in the Nilgiri Biosphere Reserve, India

Abstract

The Long-billed Vulture (LBV) population was systematically monitored across four nesting colonies in the Nilgiri Biosphere Reserve (NBR) throughout three extended breeding seasons. Breeding success rates between years ranged from 83.33% in 2018–2019 and 62.5% in 2020–2021. Nesting was monitored at the cliff sites, consistent with prior research. Overall population fluctuations were minimal, varying between 21 individuals in 2020–2021, 17 individuals in 2018–2019, and 16 individuals in 2019–2020. There was an apparent impact of forest fires and other human disturbance activities, and certain proactive conservation measures are proposed to help address these. There was indirect evidence of other threats including poison baits targeting wild carnivores and non-steroidal anti-inflammatory drugs (NSAIDs) being widely available for use in domestic livestock. The study endorses the approach of establishing vulture-safe zones, which focus on addressing the local threats. This includes raising awareness about wildfire management, controlling toxic NSAIDs availability that are harmful to vultures, discouraging the illegal use of poison-baits, and highlighting the necessity of monitoring threats posed by power infrastructure. Due to the high mobility of LBVs, all these threats need addressing through large-scale vulture safe zone work (up to 100 km radius) surrounding the breeding colonies to secure the LBV’s long-term survival. These conservation actions are urgently needed.