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Kachel, S. M., Karimov, K., Wirsing, A. J. (2022). Predator niche overlap and partitioning and potential interactions in the mountains of Central Asia. Journal of Mammalogy, XX(X), 1–11.
Abstract: Direct and indirect interactions among predators affect predator fitness, distribution, and overall community structure. Yet, outside of experimental settings, such interactions are difficult to observe and thus poorly understood. Patterns of niche overlap among predators reflect and shape community interactions and may therefore help elucidate the nature and intensity of intraguild interactions. To better understand the coexistence of two apex predators, snow leopards (Panthera uncia) and wolves (Canis lupus), we investigated their spatial, temporal, and dietary niche overlap in summer in the Pamir Mountains of Tajikistan. We estimated population- level space use via spatial capture–recapture models based on noninvasive genetics and camera traps, diel activity patterns based on camera trap detections, and diet composition from prey remains in carnivore scats, from which we estimated coefficients between 0 and 1 for overlap in space, time, and diet, respectively. Snow leopards and wolves displayed moderate spatial partitioning (0.26, 95% confidence interval [CI]: 0.17–37), but overlapping temporal (0.77, 95% CI: 0.64–0.90) and dietary (0.97, 95% CI: 0.80–0.99) niches. Both predators relied on seasonally abundant marmots (Marmota caudata) rather than wild ungulates, their typical primary prey, suggesting that despite patterns of overlap that were superficially conducive to exploitation competition and predator facilitation, prey were likely not a limiting factor. Therefore, prey-mediated interactions, if present, were unlikely to be a major structuring force in the ecosystem. By implication, carnivore conservation planning and monitoring in the mountains of Central Asia should more fully account for the seasonal importance of marmots in the ecosystem.
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Salvatori, M., Oberosler, V., Augugliaro, C., Krofel, M., Rovero, F. (2022). Effects of free-ranging livestock on occurrence and interspecific interactions of a mammalian community. Ecological-Applications., (e2644), 1–13.
Abstract: Mammalian communities inhabiting temperate grasslands are of conservation concern globally, especially in Central Asia, where livestock numbers have dramatically increased in recent decades, leading to overgrazing and land-use change. Yet, how this pervasive presence of livestock herds affects the community of wild mammals remains largely unstudied. We used systematic camera trapping at 216 sites across remote, mountainous areas of the Mongolian Altai Mountains to assess the spatial and temporal patterns of occurrence and the interspecific relationships within a mammalian community that includes different categories of livestock. By adopting a recently proposed multispecies occupancy model that incorporates interspecific correlation in occupancy, we found several statistically strong correlations in occupancy among species pairs, with the majority involving livestock. The sign of such associations was markedly species-dependent, with larger wild species of conservation concern, namely, snow leopard and Siberian ibex, avoiding livestock presence. As predicted, we found evidence of a positive correlation in occupancy between predators and their respective main prey. Contrary to our expectations, a number of intraguild species pairs also showed positive co-occurrence, with no evidence of spatiotemporal niche partitioning. Overall, our study suggests that livestock encroaching into protected areas influences the whole local community of wild mammals. Though pastoralism has coexisted with wildlife for millennia in central Asian grasslands, our findings suggest that policies and practices to decrease the pressure of livestock husbandry on wildlife are needed, with special attention on large species, such as the snow leopard and its wild prey, which seem to be particularly sensitive to this pervasive livestock presence.
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Pal, R., Panwar, A., Goyal, S. P., Sathyakumar, S. (2022). Changes in ecological conditions may influence intraguild competition: inferring interaction patterns of snow leopard with co-predators. PeerJ, 10(e14277), 1–26.
Abstract: Background: Large-scale changes in habitat conditions due to human modifications and climate change require management practices to consider how species communities can alter amidst these changes. Understanding species interactions across the gradient of space, anthropogenic pressure, and season provide the opportunity to anticipate possible dynamics in the changing scenarios. We studied the interspecific interactions of carnivore species in a high-altitude ecosystem over seasonal (summer and winter) and resource gradients (livestock grazing) to assess the impact of changing abiotic and biotic settings on coexistence.
Methods: The study was conducted in the Upper Bhagirathi basin, Western Himalaya, India. We analyzed around 4 years of camera trap monitoring data to understand seasonal spatial and temporal interactions of the snow leopard with common leopard and woolly wolf were assessed in the greater and trans-Himalayan habitats, respectively. We used two species occupancy models to assess spatial interactions, and circadian activity patterns were used to assess seasonal temporal overlap amongst carnivores. In addition, we examined scats to understand the commonalities in prey selection.
Results: The result showed that although snow leopard and wolves depend on the same limited prey species and show high temporal overlap, habitat heterogeneity and differential habitat use facilitate co-occurrence between these two predators. Snow leopard and common leopard were spatially independent in the summer. Conversely, the common leopard negatively influences the space use of snow leopard in the winter. Limited prey resources (lack of livestock), restricted space (due to snow cover), and similar activity patterns in winter might result in strong competition, causing these species to avoid each other on a spatial scale. The study showed that in addition to species traits and size, ecological settings also play a significant role in deciding the intensity of competition between large carnivores. Climate change and habitat shifts are predicted to increase the spatial overlap between snow leopard and co-predators in the future. In such scenarios, wolves and snow leopards may coexist in a topographically diverse environment, provided sufficient prey are available. However, shifts in tree line might lead to severe competition between common leopards and snow leopards, which could be detrimental to the latter. Further monitoring of resource use across abiotic and biotic environments may improve our understanding of how changing ecological conditions can affect resource partitioning between snow leopards and predators.
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Vipin, G., T. R., Sharma, V., Kumar, B. K., Gaur, A. (2022). Kleptoparasitic interaction between Snow Leopard Panthera uncia and Red Fox Vulpes vulpes suggested by circumstantial evidence in Pin Valley National Park, India. Journal of Threatened Taxa, 14(10), 21928–21935.
Abstract: In the present study, we describe an interspecific kleptoparasitic interaction between two sympatric mammalian carnivores in the high altitudinal Trans-Himalaya region of Himachal Pradesh, India. The study was based on the inferences drawn from the circumstantial evidence (direct and indirect) noticed in the study area in Pin Valley National Park. The inferences from the analysis of the evidence suggested the interaction between a Snow Leopard Panthera uncia, a Red Fox Vulpes vulpes, and a donkey. The arrangement of evidence in a sequential manner suggested that a donkey was killed by a Snow Leopard and a Red Fox stole the food from the carrion of the Snow Leopard’s prey. The Red Fox was killed by the Snow Leopard, which was caught while stealing. The present study represents an example of kleptoparasitic interaction between the Snow Leopard and the Red Fox. This study also proves that such interactions may cost the life of a kleptoparasite and supports the retaliation behaviour of Snow Leopards.
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Roth, T. L., Howard, J. G., Donoghue, A. M., Swanson, W. F., & Wildt, D. E. (1994). Function and culture requirements of snow leopard (Panthera uncia) spermatozoa in vitro. J Reprod Fertil, 101(3), 563–569.
Abstract: Electroejaculates from eight snow leopards were used to determine how the motility of spermatozoa was influenced by (i) type of media (Ham's F10, PBS, human tubal fluid or RPMI-1640); (ii) holding temperature (23 degrees C versus 37 degrees C); (iii) washing of spermatozoa and (iv) a sperm metabolic enhancer, pentoxifylline. The duration of sperm motility was assessed by evaluating samples in each treatment every hour for 6 h and a sperm motility index (a value combining percentage sperm motility and rate of forward progression) calculated. Spermatozoa from the Ham's F10, PBS and PBS plus pentoxifylline treatments were also co-incubated with zona-intact, domestic cat eggs that were fixed and evaluated for spermatozoa bound to the zona pellucida, penetrating the outer and inner layers of the zona pellucida and within the perivitelline space. During the 6 h co-incubation, the sperm motility index in PBS with pentoxifylline was greater (P < 0.05) than in PBS alone which, in turn, was greater (P < 0.05) than in the other three test media. Washing the spermatozoa enhanced (P < 0.05) motility in both PBS and PBS plus pentoxifylline relative to unwashed samples, but there was no effect (P > 0.05) of holding temperature. Pentoxifylline supplementation enhanced (P < 0.05) the proportion of cat eggs with bound, but not penetrated, snow leopard spermatozoa in the inner layer of the zona pellucida, and there were no spermatozoa in the perivitelline space.(ABSTRACT TRUNCATED AT 250 WORDS)
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Raghavan, B., Bhatnagar, Y., & Qureshi, Q. (2003). Interactions between livestock and Ladakh urial (Ovis vignei vignei); final report.
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).
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Ale, S., & Brown, J. (2007). The contingencies of group size and vigilance (Vol. 9).
Abstract: Background: Predation risk declines non-linearly with one's own vigilance and the vigilance of others in the group (the 'many-eyes' effect). Furthermore, as group size increases, the individual's risk of predation may decline through dilution with more potential victims, but may increase if larger groups attract more predators. These are known, respectively, as the dilution effect and the attraction effect.
Assumptions: Feeding animals use vigilance to trade-off food and safety. Net feeding rate declines linearly with vigilance.
Question: How do the many-eyes, dilution, and attraction effects interact to influence the relationship between group size and vigilance behaviour?
Mathematical methods: We use game theory and the fitness-generating function to determine the ESS level of vigilance of an individual within a group.
Predictions: Vigilance decreases with group size as a consequence of the many-eyes and dilution effects but increases with group size as a consequence of the attraction effect, when they act independent of each other. Their synergetic effects on vigilance depend upon the relative strengths of each and their interactions. Regardless, the influence of other factors on vigilance – such as encounter rate with predators, predator lethality, marginal value of energy, and value of vigilance – decline with group size.
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Namgail, T. (2004). Interactions between argali and livestock, Gya-Miru Wildlife Sanctuary, Ladakh, India, Final Project Report.
Abstract: Livestock production is the major land-use in Ladakh region of the Indian Trans-Himalaya, and is a crucial sector that drives the region's economy (Anon, 2002). Animal products like meat and milk provide protein to the diet of people, while products like wool and pashmina (soft fibre of goats) find their way to the international market. Such high utility of livestock and the recent socio-economic changes in the region have caused an increase in livestock population (Rawat and Adhikari, 2002; Anon. 2002), which, if continue apace, may increase grazing pressure and deteriorate pasture conditions. Thus, there is an urgent need to assess the impact of such escalation in livestock population on the regions wildlife. Although, competitive interaction between wildlife and livestock has been studied elsewhere in the Trans-Himalaya (Bhatnagar et al., 2000; Mishra, 2001; Bagchi et al., 2002), knowledge on this aspect in the Ladakh region is very rudimentary. The rangelands of Ladakh are characterised by low primary productivity (Chundawat & Rawat, 1994), and the wild herbivores are likely to compete with the burgeoning livestock on these impoverished rangelands (Mishra et al., 2002). Thus, given that the area supports a diverse wild ungulate assemblage of eight species (Fox et al., 1991b), and an increasing livestock population (Rawat and Adhikari, 2002), the nature of interaction between wildlife and livestock needs to be assessed. During this project, we primarily evaluated the influence of domestic sheep and goat grazing on the habitat use of Tibetan argali Ovis ammon hodgsoni in a prospective wildlife reserve in Ladakh.
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