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Suryawanshi, K. R., Bhatnagar, Y., & Mishra, C. (2009). Why should a grazer browse? Livestock impact on winter resource use by bharal Pseudois nayaur
. Oecologia, , 1–10.
Abstract: Many mammalian herbivores show a temporal diet variation between graminoid-dominated and browse dominated diets. We determined the causes of such a diet shift and its implications for conservation of a medium sized ungulate-the bharal Pseudois nayaur. Past studies show that the bharal diet is dominated by graminoids (>80%) during summer, but the contribution of graminoids declines to about 50% in winter. We tested the predictions generated by two alternative hypotheses explaining the decline: low graminoid availability during winter causes bharal to include browse in their diet; bharal include browse, with relatively higher nutritional quality, in their diet to compensate for the poor quality of graminoids during winter. We measured winter graminoid availability in areas with no livestock grazing, areas with relatively moderate livestock grazing, and those with intense livestock grazing pressures. The chemical composition of plants contributing to the bharal diet was analysed. The bharal diet was quantiWed through signs of feeding on vegetation at feeding locations. Population structures of bharal populations were recorded using a total count method. Graminoid availability was highest in areas without livestock grazing, followed by areas with moderate and intense livestock grazing. The bharal diet was dominated by graminoids (73%) in areas with highest graminoid availability. Graminoid contribution to the bharal diet declined monotonically (50, 36%) with a decline in graminoid availability. Bharal young to female ratio was 3 times higher in areas with high graminoid availability than areas with low graminoid availability. The composition of the bharal winter diet was governed predominantly by the availability of graminoids in the rangelands. Our results suggest that bharal include more browse in their diet during winter due to competition from livestock for graminoids. Since livestock grazing reduces graminoid availability, creation of livestock-free areas is necessary for the conservation of grazing species such as the bharal and its predators including the endangered snow leopard in the Trans-Himalaya.
Suryawanshi, K. R., Bhatnagar, Y. V. B., Redpath, S., Mishra, C. (2013). People, predators and perceptions: patterns of livestock depredation by snow leopards and wolves. Journal of Applied Ecology, 50, 550–560.
Abstract: 1. Livestock depredation by large carnivores is an important conservation and economic concern
and conservation management would benefit from a better understanding of spatial variation
and underlying causes of depredation events. Focusing on the endangered snow leopard
Panthera uncia and the wolf Canis lupus, we identify the ecological factors that predispose
areas within a landscape to livestock depredation. We also examine the potential mismatch
between reality and human perceptions of livestock depredation by these carnivores whose
survival is threatened due to persecution by pastoralists.
2. We assessed the distribution of the snow leopard, wolf and wild ungulate prey through field
surveys in the 4000 km2 Upper Spiti Landscape of trans-Himalayan India. We interviewed local
people in all 25 villages to assess the distribution of livestock and peoples’ perceptions of the risk
to livestock from these carnivores. We monitored village-level livestock mortality over a 2-year
period to assess the actual level of livestock depredation. We quantified several possibly influential
independent variables that together captured variation in topography, carnivore abundance
and abundance and other attributes of livestock. We identified the key variables influencing livestock
depredation using multiple logistic regressions and hierarchical partitioning.
3. Our results revealed notable differences in livestock selectivity and ecological correlates of
livestock depredation – both perceived and actual – by snow leopards and wolves. Stocking
density of large-bodied free-ranging livestock (yaks and horses) best explained people’s threat
perception of livestock depredation by snow leopards, while actual livestock depredation was
explained by the relative abundance of snow leopards and wild prey. In the case of wolves,
peoples’ perception was best explained by abundance of wolves, while actual depredation by
wolves was explained by habitat structure.
4. Synthesis and applications. Our results show that (i) human perceptions can be at odds
with actual patterns of livestock depredation, (ii) increases in wild prey populations will intensify
livestock depredation by snow leopards, and prey recovery programmes must be accompanied
by measures to protect livestock, (iii) compensation or insurance programmes should
target large-bodied livestock in snow leopard habitats and (iv) sustained awareness
programmes are much needed, especially for the wolf.
Suryawanshi, K. R. (2009). Towards snow leopard prey recovery: understanding the resource use strategies and demographic responses of bharal Pseudois nayaur to livestock grazing and removal; Final project report.
Abstract: Decline of wild prey populations in the Himalayan region, largely due to competition with livestock, has been identified as one of the main threats to the snow leopard Uncia uncia. Studies show that bharal Pseudois nayaur diet is dominated by graminoids during summer, but the proportion of graminoids declines in winter. We explore the causes for the decline of graminoids from bharal winter diet and resulting implications for bharal conservation. We test the predictions generated by two alternative hypotheses, (H1) low graminoid availability caused by livestock grazing during winter causes bharal to include browse in their diet, and, (H2) bharal include browse, with relatively higher nutrition, to compensate for the poor quality of graminoids during winter. Graminoid availability was highest in areas without livestock grazing, followed by areas with moderate and intense livestock grazing. Graminoid quality in winter was relatively lower than that of browse, but the difference was not statistically significant. Bharal diet was dominated by graminoids in areas with highest graminoid availability. Graminoid contribution to bharal diet declined monotonically with a decline in graminoid availability. Bharal young to female ratio was three times higher in areas with high graminoid availability than areas with low graminoid availability. No starvation-related adult mortalities were observed in any of the areas. Composition of bharal winter diet was governed predominantly by the availability of graminoids in the rangelands. Since livestock grazing reduces graminoid availability, creation of livestock free areas is necessary for conservation of grazing species such as the bharal and its predators such as the endangered snow leopard in the Trans-Himalaya.