JODHPUR, June 7 -- A comprehensive ecological assessment by Wildlife Institute of India (WII) has found that wind turbines in Rajasthan's Thar Desert are responsible for an estimated 13,359 bird deaths annually, including 953 raptors, primarily due to collisions with turbine blades and associated infrastructure. Conducted across a 3,000 sq km landscape in the desert containing around 900 turbines, the study estimated an average of 1.24 bird deaths per turbine per month. The adjusted annual mortality rate-4,470 birds per 1,000 sq km-places this region near the upper limit of global estimates of wind turbine-related bird deaths. According to the study - conducted during January 2020 to September 2021, and published in the Scientific Reports journal on June 1, 2025 - carcass surveys conducted at 90 randomly selected turbines showed 124 bird deaths, whereas no carcasses were found at nearby control sites without turbines. After correcting for scavenger removal and detection biases, the researchers concluded that wind turbine-related mortality was substantially higher than natural causes. "This is not just a conservation concern for India but a globally significant issue," senior wildlife scientist Dr Yadvendradev Jhala, one of the authors of the study, said. "We studied bird mortality at wind farms in Thar Desert; a renewable energy hotspot, harbouring 300 bird species, including critically endangered vultures and bustards." According to the study, most of the carcasses were found within a 150-metre radius of the turbines and could be attributed either to direct collisions or electrocution from adjacent power lines. The researchers treated these as a compounded impact of turbines and their infrastructure, while noting the difficulty in distinguishing the specific cause of each death. The study noted that the adjusted annual mortality rate of 14.9 birds per turbine is significantly higher than those reported from other parts of India. According to the findings, raptors and falcons - both birds of prey - are the worst-hit, with 39% of carcasses belonging to Accipitridae and Falconidae families. These included species such as the white-rumped vulture, tawny eagle, and laggar falcon - all of which are near-threatened species. Habitat type also strongly influenced mortality, the study found, adding that collision rates were higher in flat grassland and shrubland and lower in undulating vegetated dunes. Bird deaths were also seasonally variable, with higher mortality from October to February, coinciding with the migratory season along the Central Asian Flyway. The bird mortality rates, the study found, declined between March and September. Although no Great Indian Bustard was found dead during the surveys, the study highlighted that this critically endangered species has increasingly avoided areas where turbines are installed. "Our field observations indicate that Great Indian Bustard usage had reduced in wind turbine areas post installation, but did not reduce in adjoining control areas without wind farms," the study noted. Calling the Thar Desert an important bird area that supports 65 migratory and 20 threatened species, the study stressed the need for ecologically informed planning of wind energy infrastructure. "Our study urges that windfarms be brought under the umbrella of environmental impact assessments," said Jhala. "More specifically, we highlight the need to consider factors such as avoiding critical habitats of raptors, bustards, and other threatened species when planning future installations; undertaking large-scale testing of mitigation measures like painting half of one blade black and exploring other innovations such as bird-detecting camera systems that can trigger turbine shutdowns to prevent collisions; and ultimately mainstreaming the most effective solutions."...