OSAI

Tamil Nadu, India (May 2004)

Principal Investigator: Mr. A. Durairasu, I.F.S., Dr. B. Ramakrishnan

Funded by: Coimbatore Forest Department, Tamilnadu Forest Department

The influx of elephant population in to the Coimbatore Forest Division occurs mainly during the post-monsoon and dry season periods. Elephant population from Bandipur Tiger Reserve, Mudumalai Wildlife Sanctuary, Nilgiri North and South Forest Division intensifies for a period of 3-4 months at a density of 1.5 elephants per sq km. However, this ecological density exists only for a short period. Although elephants migrate to this division only for spatio-temporal use including part of its annual home range, any threat to this reserve forest would affect the elephant population in the Nilgiri Biosphere Reserve.

The contiguous large forest area has shrunk, giving rise to narrow forest corridors, which are crucial to the survival of many wild animals, especially the large ones that need a bigger habitat such as elephants, gaurs and large carnivore communities.  The major objectives of the project were to assess habitat quality of these corridors, their use by elephants, extent of man-elephant conflict and the impact of developmental activities on elephant movement.

The study was carried out between January and April 2004.  The field studies included food vegetation plots, (17) questionnaire based surveys, and interviews with local people and officials.

Five corridors that are critical to contiguity of habitat within the division were identified.  Two corridors, namely, Kallar-Jaccanare and Kallar-Gandhapallam were extensively studied by Sivaganesan, et al., (2000).  The other three corridors, namely, Anaikatti-Anuvavi, Maruthamalai-Thanikandy, and Kalkothi-Walayar were also studied during this project period.  Even though there was no wide variation among the tree species (32 to 34), very few species were found to be dominant in all corridors.

Thus, Albizzia amara, Bamboosa auridinaceae, Euphorbia antequorum, and Tectona grandis accounted for about 30% of the tree species in all three corridors.  It is interesting to note that, elephant food species formed a high proportion of the tree species except Euphorbia antequorum.
   
The other important factors such as water and natural saltlicks were more in number in the Kalkothi-Walayar corridor (Perennial water sources 9, natural saltlicks 5). Resting sites 19 were more in Maruthamalai-Thanikandi corridor). 

Direct sightings of elephants were very few due to the short duration of the project period. Kallar-Jaccanare corridor had the highest number of sightings (25 elephants in 3 herds) followed by Anaikatti-Anuvavi corridor (22 elephants in 5 herds).

Agriculture crop damage by elephants was high in Manglapalayam, Karadimadai, and Perumalkoilpathy with the maximum gross loss of Rs.2,81,000, Rs.1,87,000, and Rs.1,57,000 respectively among the three corridors.  No significant variation between family herds and bulls was observed in crop depredation among the corridors.  Although family herds and bulls raided the crops frequently, the post-pubertal (males of 15-25 years) recorded a high mortality by electrocution. 

The agricultural crops such as ragi, sorghum, sugarcane, and avarai were the most raided crops. Chilly, Grapes, and Marigold were the least raided crops by elephants in all corridors.     

Indiscriminate growth of various developmental activities all along the corridor fringe areas severely hampered the elephants’ daily and seasonal use pattern in Coimbatore Forest Division. In many areas these developmental activities blocked the corridors.