ECOLOGICAL SEPARATION BETWEEN LIVESTOCK
AND THE LADAKH URIAL (Ovis Vignei Vignei)
- Bindu Raghavan, Yash Veer Bhatnagar & Qamar Qureshi
Abstract
The Ladakh urial is an endangered subspecies of wild sheep endemic to the Indian Trans-Himalayan region of Ladakh. Its total population is estimated to be around 1000-1500 individuals scattered in small, isolated pockets along the valleys of the Indus and Shyok rivers. Hunting for sport and meat, especially during the wars in the 1960’s decimated their numbers to a great extent. More recently, however, they are increasingly threatened by human activities and livestock grazing.
To investigate the effect of potential competition with livestock on urial populations, the interactions between the two groups was studied in the resource-limiting period of winter, in 2002-03. Ecological separation between livestock and urial was studied in terms of habitat use, diet and spatial separation.
Information on use of habitat variables, by both urial and livestock, was obtained through direct observations from four monitoring trails walked ten times each. Data on availability of habitat variables was obtained from the map and through a Non-mapping technique of habitat sampling. Information on diet availability and use was obtained through sampling of ten 1x1m quadrats within 5m radius plots laid at the respective feeding sites of urial and livestock. The locations of both urial and livestock were plotted on a 1:50,000 toposheet of the area.
Both urial and livestock primarily used mid-elevations with gentle to moderate inclination (<30
o). However, the spatial overlap between them was low (Sorenson’s index of overlap Cs= 0.3), indicating avoidance of usage of the same area at the same time. This was also evidenced by the relatively substantial use of high-elevations by urial (44%), while livestock generally avoided this zone. The high-elevations were also found to be relatively sparsely vegetated, indicating higher foraging costs than in the mid-elevations. The diets of urial and sheep-goat, the most numerous livestock, overlapped substantially (Morista-Horn overlap index Cl= 0.6). Also, of the five plant species that formed bulk (81%) of the urial diet, 3 species (45.6% of urial diet) occurred primarily in the mid- and low- elevations.Thus, our results show overlap in the habitat use and diet of urial and livestock. However, urial continued to use high-elevations to a substantial degree. This was despite the fact that the high-elevations were more sparsely vegetated, had higher foraging costs, and lower availability of bulk of the urial diet species. Therefore, we suggest that urial were possibly excluded from the relatively resource-rich mid- and low- elevations by livestock, forcing them to use possibly sub-optimal resources in the high-elevations.
| Project Title | : | Interactions between livestock and Ladakh urial (Ovis vignei vignei). |
| PIs & Co-PIs | : | Sh. Qamar Qureshi & Dr. Yashveer Bhatnagar |
| Researchers | : | Bindu Raghavan, M.Sc. |
| Funding Agency | : | WII |
| Date of Initiation & Completion | : | November, 2002 to April, 2003 |