- Of the 160-odd great Indian bustards remaining in the wild, about 140 occur in the Thar desert in Rajasthan, India.
- The bird’s prime habitat in Thar, however, is being taken over by a dense, growing network of wind turbines and electric power lines that have become a death trap for the birds.
- Even a few accidental deaths due to collisions could lead to extinction of the species, according to experts.
- Conservationists and forest department officials have recommended mitigation measures, but nothing has been implemented on ground.
On Dec. 9, researchers discovered the remains of an extremely rare bird in India’s Thar Desert, in the northwestern state of Rajasthan. All that remained was a pile of bones, and large, brown feathers, fluttering beneath a power line.
The dead bird, one of the last remaining wild individuals of the critically endangered great Indian bustard (Ardeotis nigriceps), had collided with a power line, said Sutirtha Dutta, a bustard expert at the Wildlife Institute of India (WII) in Dehradun.
“This year alone, we have observed two such power line-related deaths of great Indian bustards in the area,” he said, both casualties occurring near Rajasthan’s Desert National Park. There might have been more such deaths that went unnoticed, he added. [A third Indian bustard in the region was killed due to collision with a power line on Dec. 28, after this story was published.]
“Collisions with power lines are currently one of the biggest threats to the Indian bustards,” said Anoop K.R., the deputy conservator of forests at the Desert National Park near Jaisalmer.
Video by Vikas Verma/Wildlife Institute of India.
Once widespread across India’s grasslands and dry rural landscapes, the ostrich-like Great Indian Bustard has disappeared from across 90 percent of its former range. The Thar Desert is the last stronghold of this species: of the 160-odd birds remaining in the wild, about 140 occur in the desert. The bustard’s prime habitat in the region, however, is being rapidly taken over by agricultural fields and a growing, dense network of renewable energy power projects. These crisscrossing wind turbines and electric power lines have become a death trap for birds.
Dutta’s team, which has monitored bird collisions along power lines in the Thar Desert, has found that about five birds of various species die per kilometre of power line every month, either due to electrocution or because of the impact of collision. The most common collision victims include the endangered Egyptian vulture (Neophron percnopterus), the griffon vulture (Gyps fulvus) and the common pigeon (Columba livia). “Given that there are about 6,000 kilometres [3,730 square miles] of power line in that landscape, if we extrapolate, about 18,000 birds possibly die each month due to power lines there,” Dutta said. “This is what our preliminary results show.”
The great Indian Bustard is one of the victims.
It is a heavy bird — males can weigh up to 15 kilograms (33 pounds) — that flies at low heights. The bird also has poor frontal vision, and this smaller vertical extent to which it can see means it often does not spot the electric lines until it is too late. “The bustards only see the wires when they are already very close, and because of their heavy flight and slow movement they are unable to manoeuvre in the nick of time,” Dutta said.
This is a common problem across bustard species. The endangered Ludwig’s bustard (Neotis ludwigii) and the near-threatened kori bustard (Ardeotis kori) are two of the most commonly reported power line-collision victims in South Africa, according to a study published in 2010. Deaths due to collisions also seem to be altering the migration patterns of the great bustard (Otis tarda) in Spain.
For the Indian bustard, which is already extremely threatened, even a few such accidental deaths could lead to extinction, according to experts.
These deaths can be prevented, Dutta says. His team has recommended installing brightly coloured markings known as bird flight diverters on the transmission lines, for instance, which will make the power lines more conspicuous to the birds. While not a foolproof system, studies have shown that bird diverters can reduce collision-related deaths.
In May this year, Dutta’s team handed out over 27 bird diverters to power companies like Suzlon Energy for testing in Thar.
“But nothing has happened on ground yet,” Anoop said. “Windmill companies are not very interested in doing this because they say that this is a costly affair.”
Suzlon’s spokesperson told Mongabay in an email statement: “We, in consultation with our customers, that is, the owners of the wind project in the region, are working with Rajasthan Renewable Energy Corporation Ltd (RRECL) and the Forest Department to identify spots to install the bird diverters. Suzlon believes in proactively investing in environmental conservation in our area of operations in collaboration with the Forest Department, state power department and NGOs, for conservation of all wildlife in the region.”
The forest department and conservationists from WII have also recommended running some transmission lines underground, especially those in the high-risk zones. This is not unprecedented. The neighbouring state of Gujarat, for example, took some of its high-tension power lines underground after some 400 flamingos were killed on the lines over a span of 10 days.
In Thar, though, the power companies have not been very responsive.
“In one of the meetings I attended with the power companies and the government in Jaipur, this issue was raised and the engineers of the companies said that there is no technology for laying high-voltage lines underground,” Anoop said. “If the technology becomes available for under-grounding, we can compel the companies to do it.”
The lower-voltage power lines can, however, be taken underground, Dutta said, but time is running out. “At the current rate, this will probably be done in the next four to five years, but that will be too late. The whole point is that they have to do it right now.”
Power lines are not the only threats. As a bird that nests on the ground, the Indian bustard’s eggs are threatened by predators like dogs and crows, said Gobind Sagar Bhardwaj, the former chief conservator of forests in Rajasthan, who is now director of the state’s Sariska Tiger Reserve. “Which is why the government has created breeding closures for the birds with predator-proof fencing,” he said. “And we have had encouraging results. From 2014 onwards, we have been receiving reports of not less than half-a-dozen chicks, which is very encouraging.”
There is still hope for the bird, Bhardwaj added. “We should keep fighting for the species. And one way to do that is to start captive breeding of the birds.”
Dutta agreed. “That is one thing that can buy us some time,” he said. “Ultimately you have to reintroduce the birds to the wild, but what it can do is buy us time while we continue our conservation efforts on the ground. But captive breeding can help only if it happens soon.”
Editor’s note 31-Dec-2017: The story was updated to include a comment from Suzlon Energy Limited. We have also included a sentence noting the death of a third Indian bustard due to collision with a power line in Thar desert.