Colonization pattern, clutch size variations and nest mortalities were studied in a wild population of Painted Stork (Mycteria leucocephala) in Delhi Zoo, India during 2005–2006. Among the seven different colonies in the zoo, colony 3 was the first to be occupied in both years. Nest initiation dates were significantly different across colonies. Initiation dates of satellite colonies were 7–15 days later than the island colonies (16–19 August). Clutch size varied among different colonies (1.41–3.04) with colonies 3 and 4 exhibiting highest values, 3.04 and 2.70 respectively. Birds nesting early (<14 days since nest initiation date) had higher clutch sizes compared to later nesters and those nesting in satellite colonies. House Crow (Corvus splendens) and Black Kite (Milvus migrans) were the major predator on eggs and chicks. The significance of site specific studies in providing conservation insights and setting the foundation for long term population monitoring projects is highlighted.