Attempts to find out the number of rhinoceroses in Kaziranga were made in 1957,1961 and 1963. But the method used was very crude and were aimed at finding out the number of rhinoceroses only. During these estimates the number of rhinoceroses in Kaziranga varied from 250-300. Systematic and detail censuses of the larger mammals in Kaziranga were carried out only in 1966, 1972, 1978,1984, 1991,1993,1999,2005,2009, 2012. A special population estimation of rhinos was conducted in 2013.
These figures reveal an overall increase of population of all the species of animals, over a period of thirty-three years from 1966-1999. It is heartening to note that there is an increase in the population of rhino, the prime animal towards which our conservation efforts are oriented along with other species like Buffalo, Tiger etc. in Kaziranga.
Special population estimation beside above for Tiger in 2000, Swampdeer in 1999,2000 and 2007,Buffalo in 2008,Non human primate were done in 2009.
Direct Total Count method has been applied for all the species except Tiger, for which Pugmark and camera capture and recapture method has been applied.