For generations across India, sparrows were a common sight. Their nests, especially those of house sparrows, could be found tucked into the nooks of buildings or nestled in roof hollows and ventilators. But in recent years, these once-familiar birds have been disappearing from our surroundings.

Recent surveys and studies now echo what many have observed anecdotally — a steep decline in sparrow populations. In March, a survey by the Travancore Nature History Society, a leading Indian non-governmental organisation, revealed a noticeable drop in the sparrow population across Thiruvananthapuram and its suburbs. 

In Nedumangad, for example, only around 10 sparrows were recorded in 2024. Similarly, another study conducted in 2023 by Environmental Warriors found that nearly 41% of residents in the Patna municipal area had not seen sparrows in their neighbourhoods.

One individual who has been observing this drop in the sparrow population in urban areas over the years is Chennai-based engineer Ganeshan D.

While pursuing his postgraduate studies, Ganeshan first became aware of the urgent need for sparrow conservation. He learned that most sparrows don’t mate until they have a nest — a critical insight that would shape his conservation efforts. 

He was inspired when one of his professors, T. Murugavel, walked into class one day carrying a nest box. “He spoke about how installing these boxes in homes could help provide spaces for sparrows to nest, mate, and in turn, increase their numbers,” Ganeshan recalls.

The thought was cemented in Ganeshan’s mind. As a student, along with his peers, he would go around homes in Chennai to talk about sparrow conservation, what people could do to help, and install nest boxes.

Image credit: Ganeshan D and Shanthini, founders of Koodugal Nest. Photo by Koodugal Nest, provided to Greenauve.

“There are more sparrows in north Chennai because there are still traditional homes in the area. When high-rise buildings with glass windows take over cities, the birds are unable to fly in and build their nests,” he explains.

It was in mid-2020, as the pandemic took over the world, that Ganeshan and his wife, Shanthini, registered Koodugal Nest, an initiative focused on sparrow conservation and raising public awareness about the bird’s vanishing presence.

Ganeshan points out that sparrows play a vital role in controlling disease as they feed on cockroaches, mosquitoes, and other small insects. “They help maintain ecological balance. Without them, there would be more breeding grounds for disease-carrying insects,” he explains.

About two years before launching Koodugal Nest, the duo had started working with schools and were pleasantly surprised by how welcoming the headmasters were to the initiative. “We realised this could be a way of educating the next generation about sparrow conservation,” he says.

Today, students remain central to the project. Koodugal Nest provides students with six components to make the boxes and short training sessions to help them assemble the nests. This hands-on process not only teaches them about ecology but also gives them a sense of ownership in conservation. The students often install these boxes at their homes.

“By involving students in making the nest boxes, we are also nudging them to learn new skills. They also keep an eye on sparrow activity in the nests, which brings them closer to understanding the bird,” Ganeshan adds.

To date, Koodugal Nest has distributed about 10,000 nests in Chennai, engaged with students from 50 schools and more than five colleges. According to Ganeshan, around 60% of these nests are occupied. They have also created sparrow sanctuaries in some schools and gated communities.

“About 20% of the sparrow population has increased in North Chennai. Now we are also focusing on other parts such as Coimbatore and Velachery,” Ganeshan says.