A day-long census of birds that arrived at Otteri Lake in Vandalur was carried out by the Forest Department on Friday.
The census is an annual feature and focusses on the arrival of new birds and the increase in their numbers compared to the previous years, officials said.
A group of department staff and animal keepers at Arignar Anna Zoological Park conducted the survey.
The lake has a water-spread area of 16 acres and is protected with a 635-metre-long bund. The water storage capacity of the lake is about 8.5 crore litres. Due to the rain in November and December last year, the lake was brimming with water and as many as 31 species of 7,256 birds were recorded by the surveyors.
The species spotted include Openbill stork, grey heron, white ibis, little egret, great egret, cattle egret, Indian cormorant, little cormorant, night heron, pond heron, darter, glossy ibis, common moorhen, white-breasted water hen, dabchick or little grebe, spoonbill, spotbill duck, and common coot, officials said.
The Indian cormorant accounted for 3,259 of the birds counted, followed by the little cormorant at 1,756, zoo officials added.
