The Thar Desert doesn’t look like it could host wildlife. It consists of cracked earth, khejri trees that are far from one another and bent by hot wind, and dunes that shift overnight. But one look up, and the sky tells a different story. Desert National Park in Jaisalmer, Rajasthan hosts over 100 bird species, and among them, some of India’s most impressive predators: vultures and eagles. For decades, these birds have been watched with binoculars and admiration. Now, researchers are finally tracking them with GPS.
The Egyptian vulture is one of the Thar’s most important scavengers that feeds on carcasses, and is among the first raptors to be fitted with GPS transmitters for a landmark study. [Photo © Wildlife SOS/ Atharva Pacharne]
A study by the Wildlife Institute of India has been launched in the Thar, and is being described as its first major tagging operation in the region. The study involves fitting Global Positioning System or GPS transmitters to track the movements, ecology, breeding pattern and conservation threats of six raptor species across this vast desert landscape: red-headed vulture, white-rumped vulture, Egyptian vulture, Indian vulture, tawny eagle, and laggar falcon. Latest reports reveal that so far, four birds have been tagged — two Egyptian vultures and two tawny eagles. .
The Raptors of the Thar
Now that we know that the Thar isn’t a bird-empty desert, let’s find out more about the raptors that exist here. Of the nine vulture species found in India, seven have been recorded in the Great Indian Thar Desert: the white-rumped vulture, Indian vulture, red-headed vulture (all three Critically Endangered as per IUCN Red List of Threatened Species), Egyptian vulture (Endangered), cinereous vulture and Himalayan griffon (both Near Threatened), and Eurasian griffon (Least Concern). Across Rajasthan, over 50 raptor species have been recorded, with 34 found in the desert region, including resident and migratory bird species.
Among the vulture species recorded in the Thar, the Egyptian vulture is classified as Endangered as per IUCN, highlighting the urgent need to protect scavengers that play a vital role in maintaining ecosystem health. [Photo © Wildlife SOS/ Akash Dolas]
The desert is equally important for its eagles. The Thar hosts several eagle species — resident, migratory and passage visitors — including the tawny eagle, steppe eagle, eastern imperial eagle, greater spotted eagle, short-toed snake eagle, and Indian spotted eagle. Being host to a vast number of species sounds remarkable, but a closer look into this picture is worrying: the steppe eagle is listed as Endangered on the IUCN Red List, while the eastern imperial eagle, greater spotted eagle, tawny eagle and Indian spotted eagle are all Vulnerable. These avians aren’t playing the role of background characters in the desert. They are apex hunters whose presence or absence tells us everything about the health of the landscape beneath them.
Eagles traverse enormous distances across the Thar desert, and GPS tracking will help reveal exactly where they go and what they need to survive. In image: short-toed snake eagle. [Photo © Wildlife SOS/ Atharva Pacharne]
Raptors aren’t just spectacular hunters and aesthetic birds. They contribute to their surroundings in remarkable ways. Vultures in particular do the work that no one else will. They clean up carcasses, which keeps a check on the spread of diseases, and makes sure that the ecological cycle keeps moving. Along with the vulture species, tawny eagle and laggar falcon are raptors that feed largely on rodents and lizards and maintain ecological balance in this habitat. However, they face major challenges and threats. In order to maintain their renowned habitat, there is a need to protect these species — and vice versa.
What a GPS Tag Actually Tells Us
Think of a GPS tag as a bird’s personal logbook that it can’t lose. These GPS tags log in detailed data on movement and daily behaviour. It showcases how and where these raptors drink water, their interaction with each other, adaptation to areas, as well as their foraging locations. It can also provide real-time information on pace of flight, habitat use, and diet. The tags begin to transmit information when the birds take flight, collecting location data at regular intervals along with the temperature, elevation, and activity durations. This fine-scale information is what that simple field observation simply cannot gather.
The Himalayan griffon is a carrion-feeding scavenger that migrates to the Thar during winter, showcasing the desert’s importance as a seasonal refuge for these large soaring birds. [Photo © Wildlife SOS/ Mradul Pathak]
For the landscape of the Thar desert, this matters at great volumes. The desert is part of the Central Asian Flyway, which is a major migration corridor for avians, and researchers don’t yet know exactly which routes resident and migratory raptors use across this terrain. They need to gather information about where they feed, or which areas are most critical for their survival. GPS data can answer all of this.
A Landscape Under Pressure
What matters the most is the timing of this study. The Thar — spanning over 2,00,000 sq km across northwest India, making it one of the largest arid ecosystems in Asia — is changing fast, and not always in ways that are good for its birds and its wildlife.
The Thar naturally lacks trees and elevated perches for birds, but introducing transmission line pylons in a prominent grove area near Thar desert began playing this role for raptors across the desert. The result has been a toll of electrocutions and fatality due to collisions with power lines recorded by a study conducted specifically on raptor mortality in this area. Expansion of agriculture land and altering irrigation channels in the desert has dispersed several wildlife species from their natural habitat.
Egyptian vultures are Thar desert’s unsung sanitation workers, and can be easily recognised from a distance due to its white plumage and bare yellow face. [Photo © Wildlife SOS/ Mradul Pathak]
The Thar Desert has been identified as an excellent resource for renewable energy projects. However, planning of rapidly spreading renewable energy infrastructure in-depth knowledge of and consideration for wildlife that is also thriving across the land. The Bombay Natural History Society has therefore already developed a bird sensitivity map for the Thar landscape, specifically to guide energy infrastructure investments and reduce risk to vultures, raptors, and the Critically Endangered great Indian bustard.
Why This Study Provides Hope
Though Science doesn’t save species on its own, it makes saving them possible. Without knowing the route these birds take, where and for how long they reside in this habitat, and their dependence on resources within the Thar desert, conservation efforts by researchers, forest departments, and policymakers to protect avians would essentially be aiming blindly. GPS tagging will also provide significant avian data as disclaimers for stakeholders involved in projects taking place on the Thar desert.
The Thar desert is an excellent habitat for resident raptors like this crested serpent eagle, but challenges such as over-irrigation and construction activities are threatening their very home. [Photo © Wildlife SOS/ Mradul Pathak]
The Desert National Park is currently witnessing an unusually longer stay-back of steppe eagles and migratory vultures’, raising urgent questions about shifting migration patterns. Whether it is a reaction to extended cool weather, or the ongoing Middle East conflict, the axis of the ongoing GPS studies may perhaps point to the reason that is disrupting their migration this year.
Globally, raptors are considered one of the most threatened groups of birds. Studies suggest that over half of raptor species worldwide show declining population trends, highlighting the urgency of conservation efforts. Researchers studying raptor migration have noted that conservation is often hampered by the lack of understanding of bird migration routes and movement at a precise scale. It is integral to track more species to identify networks of movement and work toward conserving at least some of them.
The skies over the Thar desert carry stories and knowledge that we haven’t been able to explore yet. These GPS tags are finally beginning the chapters of raptor conservation. At Wildlife SOS, we believe that Science and sensitivity together are what make lasting conservation possible. We have employed the use of the latest technology to mitigate human-elephant conflict situations, to understand the adaptation of leopards in human-dominated landscapes, and to track movements and behaviour of sloth bears and Himalayan brown bears, among many more conservation projects.
Studies like these serve as constant reminders of why field research matters for species dependent on the rich landscapes of India. If you’d like to stay close to these remarkable stories and Wildlife SOS’s conservation efforts, subscribe to our newsletter, and we’ll bring them straight to your inbox.
