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The Qinghai-Tibet Plateau is a harsh environment characterized by low temperature, high altitude and hypoxia, although some native mammals may adapt well to the extreme climate. However, how animal gut microbial community structure and function adapt to extreme cold climates is not well understood. Plateau pika (Ochotona curzoniae) is an ideal animal model with which to study the effects of climate change on host adaptation by studing intestinal microorganisms. Here, we used 16S rRNA sequencing technology combined with physiological methods to investigate plateau pika gut microbiota in summer and winter. Due to limited diet resources, the pikas in winter have a lower ability of degradation and fermentation for plant-based food (reduced cellulase activity and total short-chain fatty acids) by decreasing gut microbial diversity and some functional microbes, such as fiber-degrading bacteria Oscillospira and Treponema. Metagenomic prediction showed that most of those gene functions associated with metabolism (e.g. energy metabolism and lipid metabolism) were less abundant in winter, implying that the plateau pika slows diet fermentation and weakens energy requirements in the cold season. Our results have significance for explaining the mechanism of wild plateau mammals adapting to a high-altitude cold environment from the perspective of gut microbiome. [ABSTRACT FROM AUTHOR]

Mammals rely on habitat resources for survival and reproduction. We studied microhabitats used by plateau pikas (Ochotona curzoniae) of the Qinghai-Tibetan Plateau. Microhabitat features used by pikas include sedge meadows that provide forage, burrows that provide safety from predators and cover for nests, degraded open-dirt patches, and edges between sedge meadow and open dirt patches that often have a "lip" between those microhabitats. We investigated the extent to which these edges might serve as a preferred pika microhabitat. GIS techniques were used to overlay individual pika home ranges, determined by focal and scan sampling, on a digitized map containing microhabitat features. Regions that contained multiple coinciding individual home ranges, referred to as overlap polygons, were categorized numerically based on the number of individual home ranges that overlapped each polygon. These overlap polygons were used as relative measures of pika activity. We tested the spatial relationship between pika activity and the microhabitat features of edges, burrows, and proportional area of sedge. There was a significant relationship between the number of pikas in an overlap polygon and the number of pikas in an adjacent polygon. This pattern was controlled statistically to test whether activity was influenced by the presence of potentially favorable microhabitat features. Most of the variation in number of pikas that overlapped a habitat polygon was associated with the relative amount of "edge microhabitat" between sedge meadow and degraded open dirt patches (Cohen's effect size, f 2 = 0.91). Neither burrow openings nor sedge had a strong influence on the number of pika home ranges that overlapped. The importance of microhabitat edges appeared high for plateau pikas. [ABSTRACT FROM AUTHOR]

The Tibetan fox ( Vulpes ferrilata) is generally acknowledged to be a specialist forager on its preferred prey, the burrowing lagomorph plateau pika ( Ochotona curzoniae), but whether true dependency characterizes the relationship remains unclear. We estimated the presence of Tibetan foxes in 62 habitat patches that reflected a continuum of environmental conditions within their known geographic distribution within Qinghai Province, China. We used site-occupancy modeling and quantified the abundance of plateau pikas as well as other site variables that could plausibly predict fox presence. We quantified fox presence by collecting and sequencing DNA from scats. The number of pikas and the number of their burrows were the only covariates supported in predictive models of Tibetan fox presence. The probability of site occupancy by foxes increased with pika abundance, and was close to 0 when pikas were absent even within habitat patches otherwise generally suitable. DNA-based diet analysis also allowed us to identify prey species consumed by Tibetan foxes. Approximately 99% of fox scats contained pika DNA sequences, 97% contained predominantly pika sequences, and 73% contained only pika sequences. We conclude that Tibetan foxes in this region are not merely foraging specialists of plateau pikas, but that they are obligate predators on pikas. Plateau pikas, while presently still abundant on the Qinghai-Tibetan Plateau, are considered a pest by government policy and are subject to extensive, government-funded poisoning programs. The Tibetan fox is currently at no substantial risk as a species, but this could change if pika poisoning increases in scope, intensity, or effectiveness. [ABSTRACT FROM AUTHOR]

The article studies inhibitor screening of lactate dehydrogenase C4 (LDH-C4) using black-lipped pika found in the Western Sichuan Plateau in Sichuan Province, China. It informs that LDH-C4 was found to be a good target protein for development contraceptive drugs. It states that screening inhibitors of pika LDH-C4 was carried out by virtual screening and in vitro enzyme assay.

The role of so-called pest species in alternatively causing, or responding to, changing rangeland conditions remains contentious. Most scientists have concluded that high densities of plateau pikas (Ochotona curzoniae) on the Qinghai-Tibet Plateau, China, are a response to sparsely vegetation conditions, but demographic studies to support this hypothesis are lacking. During February--July 2009 we captured, weighed, and released plateau pikas monthly on 16 plots arrayed along a continuum of vegetation cover and pika density, both of which reflected differing land use for livestock management. We estimated apparent survival of adults using the Cormack--Jolly--Seber approach and recruitment of juveniles using the Pradel approach (in program MARK), modeling both as functions of habitat conditions, including vegetation cover. The probability of an adult pika captured in February being alive and present where initially captured in late July was ~0.04; male and female survival rates were similar. Best-supported models of survival included vegetation cover and an index of late winter pika density; survival was negatively related to percent vegetation cover. Pika body condition varied monthly, and was negatively associated with percent vegetation cover during February-May, but positively associated in June. Pikas living where yaks had reduced vegetation cover displayed no lower recruitment, and higher survival, than where vegetation cover was higher. Thus, our results support the hypothesis that high pika density is a response to, rather than a cause of, "rangeland degradation." Reducing undesired high pika densities will require addressing root causes of undesirable rangeland conditions. [ABSTRACT FROM AUTHOR]