Habitat shift and time budget of the Tibetan argali: the influence of livestock grazing

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 sub-optimal 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.