Survey underway for ‘Delhi Bird Atlas’

Roughly 10% of Delhi’s geographical area will be covered this month by 37 teams, each headed by an experienced birder

The first set of surveys to create a “Delhi Bird Atlas” is underway, with teams of birders setting out different hot spots across the Capital to prepare a comprehensive database, officials aware of the matter said on Thursday. The exercise comprises two sets of surveys and the atlas is likely to be released by December 2025, they said.

Migratory birds spotted at the Okhla Bird Sanctuary in December 2024. (Sunil Ghosh/HT Photo)

Throughout the month, teams of birders and volunteers of the Delhi Bird Foundation and Bird Count India will map different species, under the state forest department’s initiative to prepare a guide on species, their geographical distribution and habitats, officials said.

Pankaj Gupta, a birder and one of the organisers involved in conducting the census, said roughly 10% of Delhi’s geographical area will be covered this month by 37 teams, each headed by an experienced birder. On Wednesday and Thursday, two teams covered the Yamuna floodplains in north Delhi and Najafgarh.

“The team in north Delhi was headed by birder Rajesh Kalra, while the team in Najafgarh had birders Kavi Nanda and Mohit Mehta mapping the species. With the festive season coming to an end, more teams will now be able to start their own surveys on the ground,” Gupta said.

The second set of surveys will be undertaken in July. For the exercise, Delhi is geographically split into grids of 6.6 sq km each—each grid has a quadrant of size 3.3 sq km, which is further divided into sub-cells of 1.1 sq km—and 145 sub-cells of 1.1 sq km each will be covered by birders.

Gupta said each sub-cell will be covered four times, with an average of 15 minutes being spent per assessment. In all, 580 checklists will be prepared, with a total of 145 hours spent birding.

“One need not cover the entire 1 sq km stretch too. The team will simply have to identify a good birding habitat and 15 minutes is enough to identify the species there. Since each area will be covered four times, it is unlikely that species will be missed,” Gupta said, adding that each team will cover eight locations.

“These checklists will be uploaded on the eBird portal, which will help collate a detailed list,” he said.

Over 200 to 250 people, including students, birders, photographers and other volunteers, are likely to be involved in preparing the atlas.