Okhla Bird sanctuary (OBS) is located in National Capital Reason, Delhi (NCR) on the river Yamuna and Okhla Barrage at the entrance of Noida in Gautam Budha Nagar district of U.P. and Eastern boundary in Noida and Western boundary in NCT of Delhi. It is one of the 466 IBAs (Important Bird Areas) in India. It is roughly 4 square kilometres in size and is one among 15 bird sanctuaries in the state. Location 28035'56.3" N Latitude and 77018'56.6" E Longitude in U.P. 28032'43.5" N Latitude and 77018'41.7" E Longitude in Delhi More than 324 bird species are reported from Okhla out of this about 50% are migratory birds and a 36% are resident birds and others are vagrant sightings or of unknown category. Forty percent of the total birds are common locally and the rest are uncommon or rare. The total bird list includes two Critically Endangered, nine vulnerable, seven Near Threatened and one Conservation Dependent species. At a closer look it can be seen that 50% of the birds reported are migratory.