The proposed site for the Navi Mumbai International Airport is home to 266 species of birds, according to a survey conducted by experts of the Bombay Natural History Society, reported The Times of India. The study conducted in 2014-'15 has led to speculation regarding the impact of the airport on the winged population within a 10-km radius of the site, as well as on flight safety.

The area where the proposed airport will be developed has high bird diversity because there is a mixture of habitats there, such as creeks, seashore, paddy fields, forest, inland wetlands and mangroves, according to the survey. "The BNHS has concerns over human life, and we want to avoid bird strikes at the airport site. Therefore, attempts should be made to make the site and adjoining areas non-attractive to birds," the study said, adding that this would necessitate conservation measures such as establishing bird sanctuaries on coasts and mangroves, away from the influence of air traffic.

Environmentalists and activists have criticised the government's plan. "We have thousands of birds flying across and around the proposed airport site. This is completely unacceptable from the safety point of view. The proposed airport needs to be relocated to an alternative site near Kalyan," said Conservation Action Trust member Debi Goenka. An activist of NGO Awaaz Foundation, Sumaira Abdulali, pointed out that the Karnala Bird Sanctuary also fell within a 10-km radius of the location.

However, naturalist and author Sunjoy Monga contended the concerns. "There is no danger to flights as a majority of the bird species seen here are the grassland variety. Only a few high-flying species like raptors are seen here, but that is the case at most airports in the country," he said.