It's a normal feature that millions of birds migrate towards tropical countries like India, during winter seasons for various reasons, and they return back to their native habitats when temperature rises at desired levels. There are documents that birds fly through specific migratory paths, as monitored by learned ornithologists. In the context of growing number of high-rise building constructions in metropolis and the tendency of raising stag heights to reduce the impacts of air pollutants by the industries. Can ornithologists comment on the height / distance from the ground or msl of different regions of the migratory paths of the birds.