Assessing the accuracy of population estimation methods for vulture populations: a case study from the Mudumalai Tiger Reserve, Tamil Nadu, India


  • S. Manigandan Department of Zoology and Wildlife Biology, Government Arts College
  • H. Byju Centre of Advanced Study in Marine Biology, Annamalai University
  • P. Kannan Department of Zoology, Thiru.Vi.Ka. Government Arts College



cow dung, carcass monitoring, critically endangered, Moyar Valley, nest count, Nilgiri Biosphere Reserve, road transect survey, vultures


Two resident and two local migratory vulture species are reported in the Mudumalai Tiger Reserve of the Nilgiri Biosphere Reserve. The early population estimates from the region are either scanty or crude. Vulture population estimation was performed using three different methods based on their breeding seasons and regional movements between 2019 and 2021. Road transect counts, nest counts, and carcass monitoring counts were used for population assessments. The road transect survey and nest site counting during the breeding season were conducted in all three years, while carcass monitoring was done in 2019 – 2020. For population estimation, three nest site colony counts were conducted for the resident Gyps bengalensis and for Gyps indicus. The other two methods, carcass monitoring and the road transect survey, were used for all four focal vulture species of the Mudumalai Tiger Reserve – Gyps bengalensisGyps indicusNeophron percnopterus and Sarcogyps calvus. Significant variation in vulture population count was observed with different assessment methods.


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How to Cite

Manigandan, S., Byju, H., & Kannan, P. (2023). Assessing the accuracy of population estimation methods for vulture populations: a case study from the Mudumalai Tiger Reserve, Tamil Nadu, India. Environmental and Experimental Biology, 21(2), 45–52.