020091 Ramakrishnan B;Ramkumar K;Kumaraguru A; Saravanamuthu R;Ashok Upreti (Zoology & Wildlife Biology Dep, Government Arts College, Udhagamandalam, The Nilgiris-643 002, Email: bio.bramki@gmail.com) : Impact of exotic weeds proliferation on the distribution of tiger (Panthera tigris) and its prey species in the Mudumalai Wildlife Sanctuary, Tamil Nadu, South India. Scient Trans Envir Technovation 2013, 6(3), 125-34.
The tiger (Panthera tigris), a "Flagship Species" in the forest ecosystem, faces several perils in all its ranges. Apart from poaching, habitat loss is also a reason for the declining of tigers. This study was undertaken during the period of November 2002 to April 2003 to understand the effect of exotic weed invasion in the tiger habitats in Mudumalai Tiger Reserve, South India. We estimated the extent of the influence of different ecological variables on the prey species of tiger and to ascertain the extent of usage pattern of tiger in Severe Weed Infested Areas (SWIA), Moderate (MWIA) and Less Weed Infested Areas (LWIA). Line transect method was applied on roads which were bisecting in these three sampling areas, and assessments were made by walking along the roads in the morning (0700 hrs-1100 hrs) and evening (1500 hrs-1830 hrs). Among the prey species, the relative density of Chital was high (38.77%) in LWIA. On the contrary, high density of Sambar was recorded in SWIA (8.34%). The mean group size of chital (Axis axis), Sambar (Cervus unicolor) and Common langur (Prespytes johini) did not significantly differ between weed-infested areas. The maximum individuals in the group of Chital (50.3-93.6 sqkm) and Sambar (9.6-17.6 sqkm) were found in LWIA. The adult male and female sex ratio of Chital was 1:0.7,1:2.4 and 1:3.3 in MWIA, LWIA and SWIA, respectively. In the case of Sambar, the adult male and female sex ratios were 1:1.5, 1:1.7 arid 1:3.1 in SWIA, MWIA and LWIA, respectively. The biomass density of major prey species of tiger such as Chital, Sambar, Wild Boar and Common Langur were available more in LWIA than other weed infested areas of this study. Apart from two direct sightings of tigers more indirect evidences such as pug marks (n=35), scats (n=12) and scrape and scent markings (n=5) were frequently encountered in the order of LWIA <60> MWIA <60> SWIA. In conclusion, since the prey population is more in LWIA the tiger population also more in this area. Even though the forest cover is more(321 sqkm), the exotic weed infestation reduces the home range of the prey populations depending upon the habitat suitability and this could be one of the indirect possible reasons for decline in tiger population in this Mudumalai Tiger Reserve.
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