A large breeding colony of River Tern Sterna aurantia in Chilika Lake, Orissa (India) P. Sathiyaselvam & S. Balachandran Sathiyaselvam, P. & Balachandran, S. 2007. Largest nesting colony of River Tern Sterna aurantia in Chilika Lake, Orissa, India. Indian Birds 3 (2): 65–66. P. Sathiyaselvam, Bombay Natural History Society, Hornbill House, Shaheed Bhagat Singh Road, Mumbai 400023, Maharashtra, India. Email:
[email protected] S. Balachandran, Bombay Natural History Society, Hornbill House, Shaheed Bhagat Singh Road, Mumbai 400023, Maharashtra, India. Email:
[email protected] Mss received on 31.viii.2006. iver Tern Sterna aurantia distribution is restricted to size and incubation period. The sign strips were numbered to tropical Asia—from Iran east through Pakistan, India identify individual nests and nest locations were marked with Rand Thailand. It inhabits inland river systems, lakes a Global Positioning System (GPS). To minimize disturbance to and rarely, estuaries (Ali & Ripley 1983; Harrison 1983). the nesting / brooding birds, surveys were mostly done early Information on the breeding biology of the species is limited. morning and late evening. Care was taken to minimize the During our waterbird population monitoring study at disturbance while moving into the colony site. Chilika Lake (19º28’–19º54’N 85º05’–85º38’E), Orissa (India), In Chilika especially at Nalabana Island, the River Tern between 2001 and 2005, a breeding colony of three tern species population began to build up from February, as birds arrived namely Gull-billed Gelochelidon nilotica, Little Sterna albifrons to the Island for breeding, and peaked in April (Fig. 1). Though and River terns was recorded on Nalabana Island (19º42’36"N territory marking and mobbing behaviour occurred in late 85º28’48"E) located in Chilika Lake.