Monthly Archives: May 2016

Eastern Swamp Deer Population Estimation 2016

Eastern Swamp Deer Population Estimation May, 2016

As Kaziranga National Park harbours the last viable population of the Eastern Swamp Deer, the monitoring of population status of this sub-species is considered crucial in forming conservation and management strategies. The early record of swamp deer population estimation is found since 1966, when opportunistic records of swamp deer sightings were collected during estimation of other animals such as rhinoceros and elephants. Such records are available for 1966, 1972, 1978, 1984 and 1993. In 1998, dedicated swamp deer estimation was conducted by the Assam Forest Department in Kaziranga National Park for the first time and subsequently estimation was conducted in 2007, 2011, 2012, 2013, 2014 and 2015. The population estimates over the years have provided with information on population trends as well as dynamics of the deer subspecies.

The post-fawning population estimation for the current year was held from 5th May to 9th May, 2016. The first day was kept for training and briefing session where various aspects of the deer biology and ecology were explained to the participating enumerators from the Assam Forest Department, NGOs etc. The actual count was carried out on 6th, 7th and 8th May, followed by data compilation and analysis on 9th May, 2015. The results were declared on 10th May, 2016

The population estimation is conducted following the “Block count” method. This method involves dividing the total area into smaller units or block based on habitat feature or other distinct terrain feature. Twenty such areas /blocks are selected in four different ranges of Kaziranga National Park where the swamp deer are most likely to be found. In each of these blocks, swamp deer are counted from elephant backs, watch towers and vehicles, by multiple observers simultaneously. Only direct observations were considered. Sex and age of each swamp deer are visually assigned based on their body size and antler characteristics (for males only). The swamp deer are grouped into four age-sex classes such as adult males, adult females, yearling and fawns. GPS and binoculars are used during the exercise to locate and record the deer in different parts of the park.

The estimation is carried out for three days. The first day, the deer are counted by 20 enumerators in 20 different block of the park using 20 Departmental elephants and subsequently, the blocks were re-counted in the next two days to detect error by changing the enumerator in each block. This ensures that individual observation bias does not affect the final result.


A total of 1148 individual Eastern Swamp Deer were counted in Kaziranga National Park during the  current population estimation in 2016.  The population size of the Eastern Swamp Deer is gradually rising over the recent years. The current population shows an increase of 19 individuals from the last year’s estimation. The low flood in last two years have reduced the mortality rate of the deer and resulted in the gradual increase of the population.

Adult Male Adult Female Yearling Fawn Total
May, 2016 284 605 83 176 1148


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