Blue Sheep Research Articles

Wild ungulates employ spatio-temporal niche partitioning to coexist with livestock in resource-limited Trans-Himalayan rangelands, India

Understanding interactions between wild ungulates and livestock is critical for the conservation and management of rangelands. Sympatric animals use a diversity of strategies such as differential use of space or time to avoid interspecific interactions, especially competition and conflict. This study investigated the seasonal (summer and winter) spatial and temporal interaction of three wild ungulates; Tibetan argali, kiang, and blue sheep with livestock (sheep and goat) using camera trap data collected between 2020 and 2022 in different seasons (14,340 camera trap days and 234 locations). Blue sheep and livestock show the highest level of temporal overlap in summer and winter as both are diurnal irrespective of the season. The highest spatial overlap is observed between kiang and livestock in summer and winter. In the summer, kiang shows multiple activity peaks throughout the day as well as night i.e. cathemeral activity, possibly a strategy to avoid competition with livestock by using the same space actively and repetitively but for shorter periods. This allows them to access forage and water as needed. A significant avoidance of livestock by argali in terms of space use was observed. Based on our analysis, we argue that avoidance behavior by argali is a survival strategy in response to anthropogenic pressure and hunting in the past. The spatio-temporal coordination at a finer scale facilitates coexistence in our study area, which allows ungulates and livestock to exploit resources more effectively in the study area. The findings of this multi-scale spatio-temporal analysis provide insights into habitat preferences of wild ungulates and livestock and species-specific behaviour to avoid competition. These insights are critical to develop robust strategies and policies to conserve biodiversity while also supporting the livelihood of local communities in a multi-use landscape.

Factors influencing the distribution, risk, and transport of microplastics and heavy metals for wildlife and habitats in “island” landscapes: From source to sink

Microplastics (MPs) and heavy metals (HMs) are important pollutants in terrestrial ecosystems. In particular, the “island” landscape’s weak resistance makes it vulnerable to pollution. However, there is a lack of research on MPs and HMs in island landscapes. Therefore, we used Helan Mountain as the research area. Assess the concentrations, spatial distribution, ecological risks, sources, and transport of MPs and HMs in the soil and blue sheep (Pseudois nayaur) feces. Variations in geographical distribution showed a connection between human activity and pollutants. Risk assessment indicated soil and wildlife were influenced by long-term pollutant polarization and multi-element inclusion (Igeo, Class I; PHI, Class V; RI (MPs), 33 % Class II, and 17 % Class IV; HI = 452.08). Source apportionment showed that tourism and coal combustion were the primary sources of pollutants. Meanwhile, a new coupling model of PMF/Risk was applied to quantify the source contribution of various risk types indicated transportation roads and tourism sources were the main sources of ecological and health risks, respectively. Improve the traceability of pollution source risks. Furthermore, also developed a novel tracing model for pollutant transportation, revealing a unique “source-sink-source” cycle in pollutant transportation, which provides a new methodological framework for the division of pollution risk areas in nature reserves and the evaluation of spatial transport between sources and sinks. Overall, this study establishes a foundational framework for conducting comprehensive risk assessments and formulating strategies for pollution control and management.

Harnessing Drones for Snow Leopard Conservation

Censusing snow leopard prey species like argali, ibex or blue sheep, is time-consuming, expensive, and challenging. We tested thermal-sensor-equipped drones to census ungulate populations in Mongolia’s Ikh Nart Nature Reserve. In 2019 and 2022 we used drones to detect wild ibex and argali. Here we report on 2022 findings: ~400 km along 5 fixed transects totaling forty-three missions, including several double count surveys. Drones detected 259 prey animals and 265 livestock; on average, 34% of all sightings were in areas obscured by topographic features from ground-based observers. Overall, tests reinforced the utility of drones for counting ungulates, along with highlighting important issues and future advances for supporting largely autonomous prey surveys. We recommend biologists build upon existing technology to attain an inexpensive, easy to use, and field ready set of equipment and procedures that can reliably improve or replace traditional walking or transect count methods for large prey species.

Multi-omics reveal the gut microbiota-mediated severe foraging environment adaption of small wild ruminants in the Three-River-Source National Park, China.

The Tibetan antelope (Pantholops hodgsonii), blue sheep (Pseudois nayaur), and Tibetan sheep (Ovis aries) are the dominant small ruminants in the Three-River-Source National Park (TRSNP). However, knowledge about the association between gut microbiota and host adaptability remains poorly understood. Herein, multi-omics sequencing approaches were employed to investigate the gut microbiota-mediated forage adaption in these ruminants. The results revealed that although wild ruminants (WR) of P. hodgsoni and P. nayaur were faced with severe foraging environments with significantly low vegetation coverage and nutrition, the apparent forage digestibility of dry matter, crude protein, and acid detergent fiber was significantly higher than that of O. aries. The 16s rRNA sequencing showed that the gut microbiota in WR underwent convergent evolution, and alpha diversity in these two groups was significantly higher than that in O. aries. Moreover, indicator species, including Bacteroidetes and Firmicutes, exhibited positive relationships with apparent forage digestibility, and their relative abundances were enriched in the gut of WR. Enterotype analysis further revealed that enterotype 1 belonged to WR, and the abundance of fatty acid synthesis metabolic pathway-related enzyme genes was significantly higher than enterotype 2, represented by O. aries. Besides, the metagenomic analysis identified 14 pathogenic bacterial species, among which 10 potentially pathogenic bacteria were significantly enriched in the gut microbiota of O. aries. Furthermore, the cellulolytic strains and genes encoding cellulase and hemicellulase were significantly enriched in WR. In conclusion, our results provide new evidence of gut microbiota to facilitate wildlife adaption in severe foraging environments of the TRSNP, China.

Can livestock grazing dampen density‐dependent fluctuations in wild herbivore populations?

Abstract Conservation policy for the high mountains of Asia increasingly recognises the need to encompass large multi‐use landscapes beyond the protected area network. Due to limited long‐term research in this region, our understanding of even fundamental processes, such as factors regulating large mammal populations is poor. Understanding the factors that regulate animal populations, especially those generating cyclicity, is a long‐standing problem in ecology. Long‐term research across multiple taxa (mainly from Europe and North America) has focussed on the relative roles of food and predation in generating cyclicity in population dynamics. It remains unclear how trophic interactions that are influenced by anthropogenic stressors can affect population dynamics in human‐modified landscapes. We present a 10‐year study to compare the effects of livestock grazing on density‐dependent dynamics in two populations of bharal, Pseudois nayaur, in the Himalayas. We combine this with a mechanistic understanding of whether density dependence in these two sites acts predominantly by affecting adult survival or recruitment. We compared and quantified density dependence in the bharal population by fitting Bayesian Gompertz state‐space models. We found evidence for negative density dependence which indicates possible cyclic dynamics in the bharal population of the site (Tabo) with low livestock density. The population dynamics of this site were driven by recruited offspring—with a 2‐year density‐dependent lag effect—rather than adult survival. In the site with high livestock density (Kibber), this density dependence was not detected. We postulate the potential role of excessive grazing by livestock in affecting offspring recruitment, thereby affecting the bharal population in Kibber. Synthesis and applications: Our results suggest that conservation action to facilitate wild herbivore population recovery, such as the development of protected areas and village reserves, needs to account for density‐dependent regulation. Sites with trophy hunting require continuous monitoring to understand the effects of density dependence so that appropriate hunting quotas can be formulated.

Maintaining the native gut microbiota of bharal (Pseudois nayaur) is crucial in ex situ conservation.

As wildlife protection continue to strengthen, research on the gut microbiota of wildlife is increasing. Carrying out conservation and research on endangered species in the Qinghai Tibet Plateau plays an important role in global biodiversity conservation. This study utilized 16S rRNA sequencing of fecal samples to investigate the composition, function, and changes of the gut microbiota of bharal in different environments, seasons, and genders. The results showed that Firmicutes and Bacteroidota were the dominant phyla and UCG-005, Bacteroides, UCG-010 were the dominant genera of bharal. In the wild, the abundance of Firmicutes increased which was conducive to the decomposition and utilization of cellulose, hemicellulose, and carbohydrate. Due to the variety of food types and nutrition in different seasons, the composition and function of gut microbiota were obviously different between genders. Compared with zoo, higher alpha diversity, a more complex gut microbiota network structure, and stronger metabolic function were conducive bharal to adapting to the wild environment. In the zoo, captive bharals were fed foods rich in high fat and protein, which increased the abundance of Bacteroidota and reduced the alpha diversity of gut microbiota. A fixed diet unified the gut microbiota between genders of bharal. It is very important to pay attention to the impact of captive environments and maintain the native gut microbiota of wildlife.

Gastrointestinal parasites of the wild ungulates (Mammalia: Cetartiodactyla) in the Hemis National Park, Ladakh, India.

We evaluated the gastrointestinal parasitic prevalence and intensity of wild ungulates in the Hemis National Park of Ladakh by examining their fresh faecal samples. A total of 327 fresh faecal samples from three wild ungulates, blue sheep Pseudois nayaur (n = 127), Ladakh urial Ovis vignei vignei (n = 110), and Himalayan ibex Ibex siberica (n = 90) were collected between June 2021 and May 2022. The techniques of flotation and sedimentation were used to find parasite eggs and oocysts from the faecal samples. Out of 327 samples examined, 165 samples were infected with gastrointestinal parasites making an overall prevalence of 50.45%. Seven parasitic taxa, including one protozoan (Eimeria spp.), five nematodes (Nematodirus spp., Strongyloides spp., Haemonchus sp., Trichuris sp., and Trichostrongylus spp.), and one cestode (Monezia spp.), were found during the current investigation. Mixed infection was reported in 36 (11%) of the total examined samples. The prevalence of gastrointestinal parasites was found to be highest in blue sheep (55.11%), followed by Ladakh urial (49.09%) and Himalayan ibex (45.55%). The highest prevalence was recorded in the summer (64.42%), and the lowest in the winter (33.82%). A significant difference in parasitic prevalence was observed across seasons in each of the three wild ungulate hosts. However, there was no significant difference in the prevalence of parasites between these hosts.

A Novel Lightweight Blue Sheep Target Real-time Detection Algorithm

A Novel Lightweight Blue Sheep Target Real-time Detection Algorithm

Landscape genetics identified conservation priority areas for blue sheep (Pseudois nayaur) in the Indian Trans-Himalayan Region

The trans-Himalayan region of India, although have xeric features, still supports a unique assemblage of biodiversity, including some of the charismatic and endemic species. In the present study, we studied blue sheep (Pseudois nayaur) across the distribution range in the Western trans Himalayas of India and found about 18,775 km2 area suitable for blue sheep. The explicit Bayesian based spatial and non-spatial population structure analysis assigned blue sheep into two genetic populations, i.e., Ladakh and Lahaul-Spiti. We found relatively high genetic divergence in blue sheep which is also supported by the low current flow in Circuitscape model. With the multiple evidences, we explain landscape resistance facilitated by the landscape heterogeneity, and large patches of unsuitable habitats forced population divergence and poor functional connectivity. We found that blue sheep population has been demographically stable in the past, but showed a slight decline within the last few decades. This study is the first range-wide attempt to exhibit landscape features in shaping the spatial distribution, genetic structure and demography patterns of blue sheep in Western Himalayas, and will be of use in the conservation and management planning of blue sheep.

Seasonal Prey Abundance and Food Plasticity of the Vulnerable Snow Leopard (Panthera uncia) in the Lapchi Valley, Nepal Himalayas.

Conservation strategies for apex predators, like the snow leopard (Panthera uncia), depend on a robust understanding of their dietary preferences, prey abundance, and adaptability to changing ecological conditions. To address these critical conservation concerns, this study presents a comprehensive evidence on prey availability and preferences for snow leopards in the Lapchi Valley in the Nepal Himalayas from November 2021 to March 2023. Field data were collected through the installation of twenty-six camera traps at 16 strategically chosen locations, resulting in the recording of 1228 events of 19 mammalian species, including domesticated livestock. Simultaneously, the collection of twenty snow leopard scat samples over 3800 m above sea level allowed for a detailed dietary analysis. Photo capture rate index and biomass composition analysis were carried out and seasonal prey availability and consumption were statistically analyzed. A total of 16 potential prey species for the snow leopard were documented during the study period. Himalayan musk deer (Moschus leucogaster) was the most abundant prey species, but infrequent in the diet suggesting that are not the best bet prey for the snow leopards. Snow leopards were found to exhibit a diverse diet, consuming eleven prey species, with blue sheep (Pseudois nayaur) being their most consumed wild prey and horses as their preferred livestock. The Pianka's index of dietary niche overlap between the summer and winter seasons were 0.576, suggesting a pronounced seasonal variation in food preference corroborating with the prey availability. The scarcity of larger preys in winter is compensated by small and meso-mammals in the diet, highlighting the snow leopard's capacity for dietary plasticity in response to the variation in resource availability. This research suggests for the utilization of genetic tools to further explore snow leopard diet composition. Additionally, understanding transboundary movements and conducting population assessments will be imperative for the formulation of effective conservation strategies.

Influence of predator suppression and prey availability on carnivore occurrence in western Himalaya

AbstractSpecies assemblages are influenced by trophic and intraguild interactions, which may be competitive, facilitative, or neutral. These interactions vary in relative importance depending on resource availability. We assessed the nature of interactions among six carnivore species (Ursus arctos, Panthera uncia, Vulpes vulpes, Mustela altaica, and Martes foina) and their prey (Capra sibirica, Pseudois nayaur, Hemitragus jemlahicus, Moschus leucogaster, Ochotona sp., and Rodentia sp.) by examining their spatial–temporal overlaps using camera‐trap data gathered between 2016 and 2019 from the resource‐limited landscapes of the high Himalayas. We examined fine scale pairwise spatial interaction using multi‐species occupancy method and temporal overlap using time activity kernel densities function. Carnivore species showed relatively high spatio‐temporal overlap. We found spatial avoidance between two pairs and temporal avoidance between four out of 15 pairs. Contrary to our expectation that carnivore species would segregate due to competition in a resource‐poor environment, our results showed that they generally showed significant co‐occurrence and appeared to track their prey's activity. Our findings highlight the potentially overriding role of prey availability in influencing carnivore species occurrence in resource‐poor landscapes.

First report on the molecular detection of Enterocytozoon bieneusi in livestock and wildlife around Qinghai Lake in the Qinghai-Tibetan Plateau area, China.

Enterocytozoon bieneusi is considered to be a microsporidial species of humans and animals in the worldwide. Limited data have been reported on the prevalence and genotypes of E. bieneusi in livestock and wild animals around Qinghai Lake in the Qinghai-Tibetan Plateau area, which shares water sources, grasslands, and harsh climate with high altitudes. In this study, fecal samples from 110 Tibetan sheep, 128 yaks, 227 wild birds, 96 blue sheep (Pseudois nayaur) and 268 Przewalski's gazelle (Procapra przewalskii) around Qinghai Lake were collected, and then tested for E. bieneusi by PCR and sequencing analysis based on the ribosomal internal transcribed spacer. Among them, ten (9.09%) samples from Tibetan sheep, five (3.91%) from yaks, five (2.20%) from wild birds, one (1.04%) from wild blue sheep and two (0.75%) from Przewalski's gazelle were positive for E. bieneusi. Among sheep, there were nine E. bieneusi genotypes, including two known genotypes (BEB6 and J), and seven novel genotypes (named CHS18-CHS24). From yaks, four genotypes were identified, including two known ones (BEB4 and J) and two novel genotypes (named CHN15 and CHN16). While in wild animals, eight genotypes were found, including five different genotypes from wild bids, with three known genotypes (EbpC, J and NCF2), two novel genotypes (named CHWB1 and CHS24), and two genotypes from Przewalski's gazelle, with one known genotype J and one novel genotype CHWPG1, and one novel genotype CHWBS1 from blue sheep. According to the phylogenetic analysis, five isolates belonged to group 1, and the others were clustered into group 2. This study provides unique data on the epidemiological reports and potential risk factors for E. bieneusi in both domesticated livestock and wild animals around Qinghai Lake in the Qinghai-Tibetan Plateau area; it is important to better understand the molecular epidemiology and zoonotic potential of E. bieneusi in the Qinghai-Tibetan Plateau area.

The complete mitogenome of blue sheep (Pseudois nayaur) from the Indian Himalayan Region and its comparative phylogenetic relationship with other related species

The ‘Bharal’ or ‘Himalayan Blue Sheep’ (Pseudois nayaur) is endemic to the Himalayan and Tibetan Regions. There are gaps in the available database for the blue sheep mitogenome sequencing from the Indian region. We sequenced and characterized the whole mitogenome of one blue sheep individual using the Illumina Nova-seq 6000 platform, which was 16,718 bp in length. It included 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs), two ribosomal RNA genes (rRNAs), and one non-coding control region (D loop). It was compared with other complete mitochondrial DNA sequences of blue sheep from the NCBI database. The whole mitogenome of blue sheep was found to be highly AT-biased (60%) and had a positive AT skew (0.121) and a negative GC skew (−0.341). In 13 PCGs of blue sheep, Leucine (15.58%) and tryptophan (2.72%) occurred most frequently. A typical secondary cloverleaf structure was observed for all tRNA genes except for tRNA-Ser, where a stable structure of dihydrouridine did not develop. The phylogenetic analysis showed Indian blue sheep population formed a separate clade with a genetic distance of 3.7 to 4.1% from the Chinese blue sheep population, suggesting it to be of a different lineage and genetically qualifies the status of distinct subspecies. The results of this study will help in further phylogenetic analysis of Indian blue sheep populations in the Western and Eastern Himalayan regions and in understanding lineage identification and evolution for further research.

First description of Blastocystis sp. and Entamoeba sp. infecting zoo animals in the Qinghai-Tibetan plateau area, China.

Protozoan parasites are a well-known threat to human health, particularly for people working at or visiting zoos, and potentially cause zoonotic diseases in humans. Captive wildlife may be potential reservoirs for human infection with protozoan parasites. Therefore, focusing on zoonotic protozoan infections in zoo animals is critical. However, there is no report on this topic in the Qinghai-Tibetan Plateau region. In this study, a total of 167 and 103 fecal samples were collected from 12 animal species from Qinghai-Tibet Plateau Wildlife Park in winter and summer, respectively, to detection the prevalence of infections and subtype distribution with Entamoeba sp., Cryptosporidium sp., Giardia duodenalis, Enteromicrosporidia bieneusi sp., Blastocystis sp. by PCR assay. The results showed that a total of 21 fecal samples collected in winter, including from 2 white-lipped deer, 8 Sika deer, 6 blue sheep, 2 wolves and 3 bears, were positive for Entamoeba, with a 12.6% (21/167) positive rate. However, 4.9% (5/103) of animals in summer were positive for Entamoeba, including 1 snow leopard, 1 tiger, 1 Tibetan argali and 2 mouflon. Moreover, 1 white-lipped deer and 1 bear were found to be positive for Blastocystis sp., one zoonotic STs (ST10) was identified and found in white-lipped deer. We found no effect on season on Blastocystis sp. and Entamoeba sp. colonization. To the best of our knowledge, this study is the first description of Blastocystis sp. and Entamoeba sp. infecting zoo animals in the plateau area. The findings provide the latest data on Entamoeba sp. and Blastocystis sp. in zoo animals in China.

Factors influencing mammalian community occupancy in Dhorpatan Hunting Reserve, Nepal.

The decline in mammalian species diversity is increasing worldwide, with areas characterized by high human activities experiencing more prominent effects. Knowledge of spatial distributions of species and factors acting on them is necessary for effective management. We evaluated community-level occupancy of mammal species in Dhorpatan Hunting Reserve (DHR), Nepal using remote cameras during 15 March-15 June 2022. We used mammal species detections from remote cameras and multispecies hierarchical occupancy modeling to assess the effects of environmental and anthropogenic variables on community-level occupancy of detected mammal species. We identified a highly heterogeneous mammal species community at DHR with greatest detection probability (0.21) for red fox (Vulpes vulpes) and lowest (0.08) for blue sheep (Pseudois nayaur). Naïve occupancy ranged from 0.31 for giant-flying squirrel (Petaurista magnificus) to 0.84 for red fox. Mammal community occupancy increased with increasing canopy cover and number of livestock detections, but overall occupancy declined close to human settlements. The findings of this study can be used for developing policy at DHR for the management of mammal species through reducing the potential increase of human settlements or livestock grazing.

Free-ranging livestock affected the spatiotemporal behavior of the endangered snow leopard (Panthera uncia).

Long recognized as a threat to wildlife, particularly for large carnivores, livestock grazing in protected areas can potentially undermine conservation objectives. The interspecific interactions among livestock, snow leopards (Panthera uncia), and their wild prey in fragile Asian highland ecosystems have been a subject of debate. We strategically deployed 164 camera traps in the Wolong National Nature Reserve to systematically investigate the activities of snow leopards, their primary wild ungulate prey species, and free-ranging livestock. We found that snow leopard habitat use was influenced by both wild prey and livestock. Blue sheep served as the main wild prey that spatially attracted snow leopards and coexisted with yaks while free-ranging yaks significantly restricted snow leopard habitat use both temporally and spatially. This study challenges the conventional understanding that livestock indirectly impacts large carnivores by competing with and displacing wild prey. Our findings highlight that free-ranging yaks within the alpine canyon terrain could directly limit snow leopard habitat use, suggesting a potential risk of grazing in reducing apex predator distribution and jeopardizing their populations. Consequently, managing their coexistence in shared habitats requires a more nuanced approach. Furthermore, our research underscores the importance of further research efforts aimed at enhancing our comprehension of the complex interplay within animal communities and ecosystems. This knowledge will contribute to the development of informed, evidence-based conservation strategies and policies.

The Effect of Sexes and Seasons on the Morphological Structures of the Ruminant Digestive System of Blue Sheep (Pseudois nayaur)

Constant adaptation to environmental changes is required by ruminants to allow them to adapt to different ecological niches and feeding habits. In addition, the morphology and function of ruminant digestive systems reveal some adaptive evolutionary characteristics. Blue sheep (Pseudois nayaur) display a variety of morpho-physiological adaptations that are typical of grazers. In this study, we collected 64 adult blue sheep samples (whole animal carcasses) from the Helan Mountains, China, during different seasons. The external morphological parameters, digestive system morphological indexes, and rumen surface enlargement factors were determined. Our results reveal that the rumen and reticulum weights were positively correlated with the body weight (p = 0.004), while the food channel aperture, intestinal length, and weight of the blue sheep digestive tract presented no significant differences between different seasons (p > 0.05) and sexes (p > 0.05). There were significant differences (p < 0.001) in the density, length, and width of mastoids, and the rumen surface enlargement factor was 2.85 ± 1.37, which is typical of roughage feeders. The nutritional and ecological characteristics of blue sheep represent obvious morphological and physiological adaptations to an herbivorous diet. Adopting a quick foraging strategy allows blue sheep to rapidly consume and excrete large amounts of feed, thus obtaining the required energy for their activities and facilitating better adaption to environmental changes.

Growth Stages and Inter-Species Gut Microbiota Composition and Function in Captive Red Deer (Cervus elaphus alxaicus) and Blue Sheep (Pseudois nayaur)

Blue sheep and red deer, second-class key protected animals in China, are sympatric species with a high degree of overlap of food resources in the Helan Mountains, China. Previous studies with blue sheep and red deer in nature have shown that their physiology is closely related to their gut microbiota. However, growth stages and changes occurring in these species in captivity are still unknown. Thus, 16S rRNA gene sequencing was used to explore diversity, composition and function of the gut microbiota in these two animal species. The diversity and structure of the gut microbiota in captive blue sheep and red deer changed at different growth stages, but the dominant microbiota phyla in the gut microbiota remained stable, which was composed of the phyla Firmicutes, Bacteroidetes and Verrucomicrobia. Moreover, gut microbiota diversity in juvenile blue sheep and red deer was low, with the potential for further colonization. Functional predictions showed differences such as red deer transcription being enriched in adults, and blue sheep adults having a higher cell wall/membrane/envelope biogenesis than juveniles. Microbial changes between blue sheep and red deer at different growth stages and between species mainly depend on the abundance of the microbiota, rather than the increase and absence of the bacterial taxa.

Food webs reveal coexistence mechanisms and community organization in carnivores

Globally, massive carnivore guild extirpations have led to trophic downgrading and compromised ecosystem services. However, the complexity of multi-carnivore food webs complicates accurate identification of species interactions and community organization. Here, we used fecal DNA metabarcoding to investigate three communities that together encompass eight large- and meso-carnivore species and their 44 prey taxa of the Qinghai-Tibet Plateau (QTP), one of the last places on Earth that still harbors intact carnivore assemblages. Quantitative food-web analyses revealed pronounced interspecific variations in the carnivores' prey compositions and dietary partitioning both between and within guilds. Additionally, body masses of the carnivores and their prey exhibited consistent hump-shaped correlations across communities. Overall, differences in prey diversity, size category, and proportional utilization among the carnivore species result in trophic niche segregation that likely promotes carnivore coexistence in the harsh QTP environment. Network structure analyses detected significant modularity in all food webs but nestedness in only one. Furthermore, network characterization identified pikas (Ochotona spp.), bharal (Pseudois nayaur), and domestic yak (Bos grunniens) as potential keystone prey across the areas. Our results paint a holistic and detailed picture of the QTP carnivore assemblages' trophic networks and demonstrate that the combined use of the molecular dietary approach and network analysis can generate structural insights into carnivore coexistence and can identify functionally important species in complex communities. Such knowledge can help safeguard carnivore guild integrity and enhance community resilience to environmental perturbations in the sensitive QTP ecosystems.

Unknown Slope-Oriented Research on Model Predictive Control for Quadruped Robot

There are many undulating terrains in the wild environment. In order to realize the adaptive and stable walking of quadruped robots on unknown sloped terrain, a slope-adaptability model predictive control (SAMPC) algorithm is proposed in this work. In the absence of external vision sensors, the orientation and inclination of the slope are estimated based on the joint position sensors and inertial measurement units (IMU). In an effort to increase the stability margin, the adaptive algorithm adjusts the attitude angle and the touch-down point of the swing leg. To reduce the slipping risk, a nonlinear control law is designed to determine the friction factor of the friction cone constraint from the inclination of the slope. We validate the effectiveness of the framework through a series of simulations. The automatic smooth transition from the flat to the unknown slope is achieved, and the robot is capable of walking in all directions on the slope. Notably, with reference to the climbing modal of blue sheep, the robot successfully climbed a 42.4° slope, proving the ultimate ability of the proposed framework.