Have species adapted to wind turbines?
During a visit to Tirunelveli, Thoothukudi and Kanniyakumari districts, when Mongabay-India asked residents if they had seen any bird/bat collisions, some said they had seen collisions, but most of them they said the birds have adapted to the wind turbines. , as wind turbines in the landscape have been around for more than two decades now.
They point out the brightly painted blade tips in newly installed wind turbines (as mandated by the Department of the Environment) and say the paint makes the wind turbines more visible to birds, thereby reducing collisions.
So, have certain species in the landscape adapted to the presence of wind turbines? And have wind company interventions, such as painting the blades bright orange and installing bird deflectors, helped reduce collisions? Stating that many birds fly at the altitude of the wind turbines present in the Tirunelveli belt, Hopeland said that although some birds have adapted to the wind turbines, they use their energy much more for their daily activities.
Citing the example of a sparrow lark, he said: “The sparrow lark (Eremopterix griseus) males usually perform their mating or courtship dance at a certain height. Now, with the presence of the windmill, the males use the top of the turbine as a landmark to perform this dance, thus using many times the energy required for this activity.
He said the cheapest path for birds, i.e. the energy needed to move from point A to point B, increases with obstacles such as wind turbines in their path.
Same assessment for different species?
While carcass surveys at wind farms may be an appropriate method to study the impact of wind turbines on birds, what is the methodology for conducting assessments for other species?
Some residents of Tirunelveli have seen peacocks collide with transformers and die. Although the peacocks do not fly at the altitude of the blades of wind turbines, locals note that they have seen them collide with transformers. It is a “clumsy bird”, they point out.
“I have seen several birds get hit by the blades of the wind turbines including owls, mammals such as fruit bats, ibises, etc. I feel happy when a bird that has difficulty navigating through the wind farm manages to escape the blades of the turbine,” said Maria Antony, a nature educator and ecologist from Panakudi, a village near Radhapuram. Panakudi has many wind turbines and there is a resting site for bald people. -fruit bats at Panakudi Police Station where hundreds of fruit bats roost during the day.
Jeremiah Rajanesan from the Dohnavur Fellowship in Radhapuram says the Fellowship land in Muppandal is a very important scrub jungle which they are trying to conserve. They have leased nine plots of land to a wind company and support wind power, but are also concerned about the area’s biodiversity.
“The ancient Tamils classified land into five categories – Kurinji (mountains), mullai (forests), marutham (cultivated land), neithal (seaside) and palace (dry land). We try to promote the conservation of mullai landscapes. The Muppandal scrub jungles are very important to us and they contain many rare species – the sambar deer breed there and there is also the rusty spotted cat. Many insects are endemic to the region. Therefore, conserving biodiversity there and carrying out assessments is important,” shares Rajanesan.
Mathivanan, a senior research associate at ATREE, adds: “In my interaction with some of the ranchers in Tirunelveli, I realized that invasive species lantana camera plant species are spreading in areas with wind turbines. This took over other vegetation and grasses and caused grazing difficulties for animals, which impacted the livelihoods of herders.
Ecologist and researcher Brawin Kumar, studying the Madras hedgehog (Paraechinus nudiventris) in Tamil Nadu emphasizes the need to study the biodiversity of arid landscapes and grasslands due to the drop in the number of hedgehogs in the state. “Hedgehogs were present in this landscape before humans. They are wild animals that face multiple threats such as habitat loss, poaching and trade. Their habitats are not wastelands but important grasslands that need to be regularly assessed,” he told Mongabay-India.
Responding to the question on the methodology for conducting assessments for different species in a landscape, Kumar said, “It is important to conduct longer biodiversity assessments in each landscape during the right season. Assessments would vary across species groups and landscapes, but also across seasons. One type of assessment simply cannot aim to understand different species in a landscape.
Kumar recommends that Environmental Impact Assessments (EIAs) be conducted before and after the establishment of renewable energy projects to better understand the impacts.
Read more: The paradox of wind farms in southern Tamil Nadu
Planning for future wind farms
Land is a finite resource. Studies have shown that land use changes triggers biodiversity decline, especially in grasslands. Before planning future wind farms, ecologists and researchers are urging developers to consider biodiversity assessments as a tool to achieve both climate and biodiversity goals.
To set up renewable energy projects and meet the country’s net zero emissions targets, India needs an area almost the size of Bihar and mostly made up of open natural ecosystems. Renewable energy projects especially wind farms in southern districts of Tamil Nadu are located in these open natural ecosystems which are mostly arid lands and grasslands rich in biodiversity. It therefore becomes essential to understand the sensitive biodiversity present in these landscapes before installing wind turbines.
“We need to plan wind farms that have the least impact on biodiversity. If painting the blades in a bright color works, all companies should be encouraged to do so. Vortex technologies (bladeless turbines) and other inventions can be explored,” Hopeland said.
BNHS in collaboration with Birdlife International is creating a bird susceptibility map for India. Explaining to Mongabay-India the purpose of this map, Selvaraj from BNHS said, “It is an important and dynamic tool.”
“With the help of the map, if we select an area, we can see if the place is very sensitive for birds. It is particularly useful for setting up wind farms and transmission lines. Species prone to collisions with wind turbines will be highlighted on this map. Potential Ramsar sites will also be included. This will be helpful for wind companies to choose areas with the least impact on birds,” Selvaraj told Mongabay-India. The researchers aim to publish this map by the end of 2022.
Mongabay-India contacted the energy department of the Tamil Nadu government to understand the measures taken to assess or conserve biodiversity in landscapes dominated by wind farms, but received no response. The story will be updated if a response is received.
Banner image: Tamil Nadu lacks biodiversity assessments in grasslands dominated by wind farms. Environmentalists recommend more biodiversity studies in the state. Photo by Narayana Swamy Subbaraman/Mongabay.