There has been a marginal decrease in the population of black buck and spotted deer at the Guindy National Park (GNP) and Raj Bhavan campus.
This was the outcome of the census conducted by the Wildlife wing of the State Forest Department at the two places on Sunday.
Population of the spotted deer was estimated to be around 1,255 and that of black buck 371. During the last census in February last year their numbers were estimated to be 1,280 and 382 respectively, according to Wildlife authorities.
The marginal decrease was due to the presence of predators inside the GNP area, they said. A senior officer said in 2003 about half a dozen jackals from the Children's Park were released into the GNP and their population had reached more than a dozen two years ago.
The jackals, which used to mainly feed on the wild hare and rats, could now be preying on the fawns of spotted deer and black bucks due to which their population has decreased marginally, the officer said.
Apart from ungulates the participants in the census also recorded the sighting of good number of star tortoises, cobra, booted-eagle, palm civet cat and a pangolin during the census.
Around 100 volunteers, including students and professors from various colleges, participated in the programme.
The Wildlife authorities formed 11 teams with nine volunteers each in a team, who walked along 11 transect lines drawn inside the GNP area to enumerate the wildlife population, the authorities added.