Abstract: An inverse relationship between individual vigilance level and group size is widely reported in many behavioral studies on animals across several taxa. It is generally held that such a relationship is due to a reduced probability of an individual being killed in larger groups. in the present investigation, I studied the vigilance behavior of the endangered Tibetan argali Ovis ammon hodgsoni in relation to group size and escape terrain. I hypothesized that an individual argali has a higher vigilance level in smaller groups and in habitats closer to cliffs than individuals living in larger groups and open areas (escape terrain). The results show that the vigilance of argali decreased with increasing group size, but there was no effect of escape terrain on its vigilance behavior. There were significant differences between age-sex groups: male, female and yearling in their time budgets. Females, compared to males and yearlings, spent more time being vigilant. They also foraged more and moved less than males. It is suggested that vigilance is an important anti-predator behavior amongst argali sheep.

Abstract: Livestock production is the primary source of livelihood and income in most of the high steppe and alpine regions of the Indian Trans-Himalaya. In some areas, especially those established or proposed for biodiversity conservation, recent increases in populations of domestic livestock, primarily sheep and goats, have raised concern about domestic animals competitively excluding wild herbivores from the rangelands. We
evaluated the influence of domestic sheep and goat grazing on the habitat use and time budget of the endangered Tibetan argali Ovis ammon hodgsoni in the proposed Gya-Miru Wildlife Sanctuary, Ladakh, India. We asked if the domestic sheep and goat grazing and collateral human activities relegate the argali to suboptimal habitats, and alter their foraging time budgets. Data were collected on habitat use and time budget of a population of c. 50 argalis before and after c. 2,000 sheep and goats moved onto their winter pasture in the Tsabra catchment of the aforementioned reserve. Following the introduction of domestic sheep and goats, argalis continued to use the same catchment but shifted to steeper habitats, closer to cliffs, with lower vegetation cover, thus abandoning previously used plant communities with denser cover. Argalis' active time spent foraging also decreased by 10% in response to the presence of livestock. These results suggest a clear disturbance effect of livestock on argalis, and indicate a potential for competition, conceivably a significant disadvantage for argalis in winter when forage availability is minimal.

Abstract: The Ladakh urial (Ovis vignei vignei) is a highly endangered animal (IUCN Red List 2000) listed in the Appendix 1 of CITES and Schedule 1 of the Indian Wildlife Protection Act 1972. Its numbers had been reduced to a few hundred individuals in the 1960s and 70s through hunting for trophies and meat (Fox et al. 1991, Mallon 1983, Chundawat and Qureshi 1999, IUCN Red List 2000). However, with the protection bestowed by the IWPA 1972, and resultant decrease in hunting, the population seems to have shown a marginal increase to about 1000-1500 individuals in its range in Ladakh (Chundawat and Qureshi 1999, IUCN Red List 2000). Although the species had in the past, been able to coexist with the predominantly Buddhist society of Ladakh, the recent increase in the population of both humans and their livestock has placed immense pressures on its habitat (Shackleton 1997, Chundawat and Qureshi 1999, Raghavan and Bhatnagar 2003). This is especially important considering that the Ladakh urial habitat coincides with the areas of maximum human activity in terms of settlements, agriculture, pastoralism and development, in Ladakh (Fox et al. 1991, Chundawat and Qureshi 1999, Raghavan and Bhatnagar 2003). Increased developmental activities such as construction of roads, dams, and military bases in these areas have also increased the access to their habitat. This has consequently made the species more vulnerable to the threats of poaching and habitat destruction (Fox et al. 1991, Chundawat and Qureshi 1999, Raghavan and Bhatnagar 2002). Pressure from increased livestock grazing is one of the major threats faced by the species today (Shackleton 1997, Fox et al. 1991, Mallon 1983, IUCN Red List 2000 Chundawat and Qureshi 1999, Raghavan and Bhatnagar 2003). In the impoverished habitat provided by the Trans-Himalayas, there is great competition for the scarce resources between various animal species surviving here (Fox 1996, Mishra 2001). The presence of livestock intensifies this competition and can either force the species out of its niche (competitive exclusion) by displacing it from that area or resource, or lead to partitioning of resources between the species, spatially or temporally, for coexistence (Begon et al. 1986, Gause 1934).