Power supply lines in Thar 'pushing' Great Indian Bustard to extinction: Researchers

By Rosamma Thomas* 
Electricity supply lines pose a huge risk to birds and affect biodiversity, but there is little research about the numbers of birds dying of such collision in the tropical nations. In August 2021, academic journal Biological Conservation carried the results of a survey conducted in 2017-18 on 4,200 sq km of the Thar Desert in Jaisalmer district of Rajasthan. This was the first comprehensive survey of this nature in the region.
Researchers marked out the area they would survey and walked along the power lines to record all findings of bird carcasses. If they found 10 or less feathers, they did not count it as a carcass since it could be blown by wind or deposited during roosting or preening. 

In the course of the study, they observed over 6,700 bird crossings over power lines and found 289 bird carcasses – the highest single species of the carcasses (15) belonged to the Egyptian Vulture.  Two carcasses of the Great Indian Bustard, a species considered critically endangered, were also found. Based on their small sample size, the researchers estimate a 16% annual mortality rate among the GIB to power lines.

“The population viability analysis revealed that the Great Indian Bustard is at imminent risk of extinction due to power line mortality,” the researchers, from the Wildlife Institute of India at Dehradun, concluded, recommending that overhead power lines in high risk areas be taken underground. This is a recommendation the Supreme Court too has endorsed in a ruling of April 2021. Bustards also lose chicks to predation and starvation, and the scientists suggested that breeding habitats be fenced off to prevent disturbance.
“The critically endangered Great Indian Bustard (Ardeotis nigriceps) has declined catastrophically because the species’ slow life history traits cannot maintain a viable population in the face of human induced mortality and habitat loss. The only viable population exists in the Thar Desert, which is a new hub for renewable energy production,” the researchers found, adding that such a situation calls for factoring in biodiversity too into plans for land use.

With increased demand for electricity and the push away from fossil fuels, renewable sources of energy are being promoted as the great solution. Power line networks are expanding, and reaching landscapes where wildlife is affected. 

“Overhead wires are causing avian mortalities through collision,” the study found. Annually, approximately 50 birds die per kilometer of power line in the Thar Desert. Overhead wires are a global conservation problem, and bird mortalities are high in the US and Canada too, where such research is of longer vintage. Some resident birds like Corvids appeared to have adapted to the human intervention.

Overhead wires are a global conservation problem, and bird mortalities are high in the US and Canada too

Research on bird mortality in India has largely concentrated on single taxa, and so these researchers were keener on assembling data for all birds in the area. Arid ecosystems like the Thar are classified as “wastelands” in India, and put to use for renewable energy projects, which are considered good for the environment. Renewable energy projects are thus supported through subsidies and granted more lenient environment clearances, since they are considered ecologically benevolent.

The arid Thar Desert is part of the Central Asian flyway, and rich in avifaunal diversity, at over 250 species. The high mortality of birds can disrupt ecosystems, affecting seed dispersal, pollination and pest control and predation. The power lines in the Thar pose a global problem on account of the many migratory species that visit the area in winter.
The authors of the study, Mohib Uddin, Sutirtha Dutta, Vishnupriya Kolipakam, Hrishika Sharma, Farha Usmani and Yadevendradev Jhala are part of the Bustard Recovery Programme of the Wildlife Institute of India, Dehradun.
A group of German researchers a few years ago questioned the whole narrative built around renewable energy, showing that billions of euros had been spent on expanding renewable energy capacity, even as carbon dioxide emissions were rising. 

They noted that wildlife protection had been subordinated to climate change mitigation, but the measures taken were not having the desired effects. That report should ideally inform policy debates in other parts of the world, where renewables are being pushed without a consideration for whether the goals initially aimed at were indeed being achieved.

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*Freelance journalist based in Pune