After winter census, Delhi to begin second round of Bird Atlas survey in May

Following the success of a winter bird survey earlier this year, Delhi’s forest and wildlife department is set to launch a month-long summer census in May to document avian species across the capital.

The survey, which will replicate the methodology of the January census, aims to provide a seasonal comparison of bird populations and contribute to the creation of the Delhi Bird Atlas—a first-of-its-kind comprehensive record of bird species, their distribution, and habitats in the city, officials said.

Expected to be released by December, the Delhi Bird Atlas will compile data from both winter and summer surveys to offer insights into resident and migratory bird populations. The January census, covering around 10% of Delhi’s 1,483 sq km area, recorded 200 bird species, including the red-crested pochard, paddyfield warbler, Eurasian kestrel, and oriental darter. The upcoming survey will help assess summer bird activity, particularly during the breeding season, officials and birding experts said.

The first census, carried out from January 1 till the first week of February, documented 200 different bird species after surveying approximately 10% of Delhi’s total geographical area of 1,483 square kilometres (sqkm).

For the census, Delhi was divided into grids of 6.6sqkm, with each grid further split into quadrants of 3.3sqkm and sub-cells of 1.1sqkm. The winter survey covered 145 sub-cells, each surveyed four times by teams from the Delhi Bird Foundation and Bird Count India, in collaboration with NGO volunteers. A total of 580 checklists were compiled.

The forest department said it plans to repeat the same methodology, with the same sub-cells to be covered over a month to assess the summer bird species.

“We plan to start the census in the first or second week of May, and will continue for a month. The same methodology will be followed as the first survey to keep everything uniform and all data will be uploaded on the eBird portal,” a senior forest department official said, adding that a meeting with birders and NGOs was held earlier this month in this regard.

This time, the department intends to involve more volunteers and NGOs, with training sessions scheduled to begin after April 15. “We have approached several organisations, including WWF India, Wildlife SOS, Asian Adventures, and the airport operator DIAL, which has been asked to assist in covering the grids near the airport. The final date for volunteer registration is April 15, after which we will start training sessions on conducting the survey and maintaining checklists,” the official said.

Pankaj Gupta, a birder involved in the census, said while the first survey in January gave an estimate of winter migratory birds, the summer census will provide more data on resident species. “Two different times of the year were chosen to give comprehensive data on the types of species found in Delhi. Birds are more active during this time of year, as it is their breeding season, so there will be more activity for birders as well,” he said.

Among the 200 species recorded in the winter survey, the most commonly spotted was the rock pigeon, with 14,127 individuals. It was followed by the common myna (6,411) and the black kite (6,082). The house sparrow ranked ninth, with 1,364 individuals recorded.

Officials believe the summer survey will further enrich the database, providing a holistic picture of Delhi’s avian biodiversity and contributing to long-term conservation efforts.