Ochotona Curzoniae Research Articles

Testis-Specific Lactate Dehydrogenase (LDH-C4) in Skeletal Muscle Enhances a Pika's Sprint-Running Capacity in Hypoxic Environment.

LDH-C4 is a lactate dehydrogenase that catalyzes the conversion of pyruvate to lactate. In mammals, ldh-c was originally thought to be expressed only in testis and spermatozoa. Plateau pika (Ochotona curzoniae), which belongs to the genus Ochotona of the Ochotonidea family, is a hypoxia tolerant mammal living 3000–5000 m above sea level on the Qinghai-Tibet Plateau, an environment which is strongly hypoxic. Ldh-c is expressed not only in testis and sperm but also in somatic tissues of plateau pika. In this study, the effects of N-propyl oxamate and N-isopropyl oxamate on LDH isozyme kinetics were compared to screens for a selective inhibitor of LDH-C4. To reveal the role and physiological mechanism of LDH-C4 in skeletal muscle of plateau pika, we investigated the effect of N-isopropyl oxamate on the pika exercise tolerance as well as the physiological mechanism. Our results show that Ki of N-propyl oxamate and N-isopropyl oxamate for LDH-A4, LDH-B4, and LDH-C4 were 0.094 mmol/L and 0.462 mmol/L, 0.119 mmol/L and 0.248 mmol/L, and 0.015 mmol/L and 0.013 mmol/L, respectively. N-isopropyl oxamate is a powerful selective inhibitor of plateau pika LDH-C4. In our exercise tolerance experiment, groups treated with inhibitors had significantly lower swimming times than the uninhibited control group. The inhibition rates of LDH, LD, and ATP were 37.12%, 66.27%, and 32.42%, respectively. Our results suggested that ldh-c is expressed in the skeletal muscle of plateau pika, and at least 32.42% of ATP in the skeletal muscle is catalyzed by LDH-C4 by anaerobic glycolysis. This suggests that pika has reduced dependence on oxygen and enhanced adaptation to hypoxic environment due to increased anaerobic glycolysis by LDH-C4 in skeletal muscle. LDH-C4 in plateau pika plays the crucial role in anaerobic glycolysis and generates ATP rapidly since this is the role of LDH-A4 in most species on plain land, which provide evidence that the native humans and animals in Qinghai-Tibet plateau can adapt to the hypoxia environment.

Herbivory and Competition of Tibetan Steppe Vegetation in Winter Pasture: Effects of Livestock Exclosure and Plateau Pika Reduction.

Rangeland degradation has been identified as a serious concern in alpine regions of western China on the Qinghai-Tibetan plateau (QTP). Numerous government-sponsored programs have been initiated, including many that feature long-term grazing prohibitions and some that call for eliminating pastoralism altogether. As well, government programs have long favored eliminating plateau pikas (Ochotona curzoniae), assumed to contribute to degraded conditions. However, vegetation on the QTP evolved in the presence of herbivory, suggesting that deleterious effects from grazing are, to some extent, compensated for by reduced plant-plant competition. We examined the dynamics of common steppe ecosystem species as well as physical indicators of rangeland stress by excluding livestock and reducing pika abundance on experimental plots, and following responses for 4 years. We established 12 fenced livestock exclosures within pastures grazed during winter by local pastoralists, and removed pikas on half of these. We established paired, permanent vegetation plots within and outside exclosures and measured indices of erosion and biomass of common plant species. We observed modest restoration of physical site conditions (reduced bare soil, erosion, greater vegetation cover) with both livestock exclusion and pika reduction. As expected in areas protected from grazing, we observed a reduction in annual productivity of plant species avoided by livestock and assumed to compete poorly when protected from grazing. Contrary to expectation, we observed similar reductions in annual productivity among palatable, perennial graminoids under livestock exclusion. The dominant grass, Stipa purpurea, displayed evidence of density-dependent growth, suggesting that intra-specific competition exerted a regulatory effect on annual production in the absence of grazing. Complete grazing bans on winter pastures in steppe habitats on the QTP may assist in the recovery of highly eroded pastures, but may not increase annual vegetative production.

Comparative ventilatory strategies of acclimated rats and burrowing plateau pika (Ochotona curzoniae) in response to hypoxic–hypercapnia

The objective of this study was to compare the different ventilatory strategies that help in coping with hypoxic–hypercapnia environment among two species: use acclimated rats and plateau pikas (Ochotona curzoniae) that live in Tibetan plateaus, and have been well adjusted to high altitude. Arterial blood samples taken at 4100m of elevation in acclimatized rats and adapted pikas revealed inter-species differences with lower hemoglobin and hematocrit and higher blood pH in pikas. A linear and significant increase in minute ventilation was observed in pikas, which help them to cope with hypoxic–hypercapnia. Pikas also displayed a high inspiratory drive and an invariant respiratory timing regardless of the conditions. Biochemical analysis revealed that N-methyl-D-aspartate receptor (NMDA) receptor gene and nNOS gene are highly conserved between rats and pikas, however pikas have higher expression of NMDA receptors and nNOS compared to rats at the brainstem level. Taken together, these results suggest that pikas have developed a specific ventilatory pattern supported by a modification of the NMDA/NO ventilatory central pathways to survive in extreme conditions imposed on the Tibetan plateaus. These physiological adaptive strategies help in maintaining a better blood oxygenation despite high CO2 concentration in burrows at high altitude.

Ecology and geographic distribution of Yersinia enterocolitica among livestock and wildlife in China

The results in this study show the prevalence of Yersinia enterocolitica varies in different animal species and regions of China. The highest prevalence is among pigs (12.91%), followed by dogs (9.80%), Ochotona curzoniae (plateau pica) (6.76%), chickens (4.50%), rodents (3.40%), cattle (2.78%) and sheep (0.89%). Pathogenic isolates comprised the majority of the Y. enterocolitica recovered from pigs (73.50%) and dogs (59.44%); whereas the nonpathogenic Y. enterocolitica made up most of poultry and wildlife recovered strains. A correlation analysis comparing the prevalence and geographic factors showed the isolation rate of Y. enterocolitica in pigs and dogs was negatively correlated with elevation (r=−0.50, P<0.05) and annual average air temperature (r=−0.43, P<0.05), but there was positive correlation with annual precipitation (r=0.43, P<0.05); conversely, the isolation rate from wildlife is positively correlated with elevation (r=0.3, P<0.05) contrary to the result seen in livestock. Twelve novel biotype 2 pathogenic Y. enterocolitica carried ail and ystB virulence genes, and one biotype 1A nonpathogenic strain positive with ail, ystB and ystA genes were isolated from Microtus fuscus (Qinghai vole) on plague foci of the Qinghai–Xizang plateau. The PFGE pattern K6GN11C30021 was predominant in pigs (44.25%) and patients (41.18%); K6GN11C30068 was predominant in dogs (40.16%). Animal isolates from the same region shared the same pattern (K6GN11C30021 and K6GN11C30012), indicating they may be from the same clone and arose through cross infection. Moreover, the identical PFGE pattern among local animals and diarrhea patients suggested that the animals may be the source of infections in these areas.

Role of glutamate and serotonin on the hypoxic ventilatory response in high-altitude-adapted plateau Pika

The highland “plateau Pika” is considered to be adapted to chronic hypoxia. We hypothesized that glutamate N-methyl-d-aspartate (NMDA) and non-NMDA receptors, nitric oxide (NO) synthase, and serotonin are involved in hypoxic ventilatory response (HVR) in Pikas. We tested the effects of NMDA (memantine) and non-NMDA receptors (DNQX) antagonists, NO synthase inhibitor (L-NAME), and selective serotonin reuptake inhibitors (fluoxetine) on ventilation and HVR in Pikas. Ventilatory parameters were measured before and after drug (or vehicle) injections in conscious Pikas at their natural living altitude (PIO2 86mmHg) and after a hypoxic challenge (PIO2 57mmHg, 3min) to assess the influence of peripheral chemoreceptor on HVR. Minute ventilation (VI) and tidal volume (Vt) increased during hypoxic challenge after vehicle injection, whereas the Ti/Ttot ratio remained unchanged. The increase in VI and Vt observed with vehicle at PIO2-57, when compared with PIO2-86, was inhibited after memantine and fluoxetine injection, whereas the DNQX injection increased HVR. At PIO2-57, L-NAME induced an increase in the Ti/Ttot ratio when compared with vehicle. Therefore, the glutamate through NMDA-R/AMPA receptor bindings and serotonin pathway are implicated at the peripheral chemoreceptor level in HVR in Pikas. However, NO influences the ventilatory pattern of Pikas at their habitual living altitude.

Distribution of sialic acid receptors and experimental infections with different subtypes of influenza A viruses in Qinghai-Tibet plateau wild pika.

BackgroundThe plateau pika (Ochotona curzoniae) is a small rabbit-like mammal that lives at high altitudes in the Qinghai-Tibet plateau and is in close contact with birds. Following the outbreak of highly pathogenic avian influenza (HPAI) H5N1 during 2005 in the migratory birds of Qinghai Lake, two clades of H5N1 have been found in pikas. However, the influenza virus receptor distribution in different tissues of this animal and its susceptibility to influenza A viruses have remained unclear.MethodsThe sialic acid receptor distribution tropism in pika was investigated using fluorescent Sambucus nigra and biotinylated Maackia amurensis I and II. Furthermore, the replication of three influenza A viruses H1N1, H3N2, and H5N1 in this animal was examined by immunohistochemistry and RT-PCR. Morphological and histopathological changes caused by infection were also analyzed with hematoxylin and eosin (H & E) staining.ResultsHuman influenza virus-recognizing SAα2,6Gal receptors are widely expressed in the lung, kidney, liver, spleen, duodenum, ileum, rectum, and heart, whereas avian influenza virus-recognizing SAα2,3Gal receptors are strongly expressed in the trachea and lung of pika. M1 could be detected in the lungs of pikas infected with H1N1, H3N2, and H5N1 by either immunostaining or RT-PCR, and in the brain of H5N1-infected pikas. Additionally, three subtypes of influenza A viruses were able to infect pika and caused varying degrees of pneumonia with epithelial desquamation and alveolar inflammatory cell infiltration. Slight pathological changes were observed in H1N1-infected lungs. A few small bronchi and terminal bronchioles were infiltrated by lymphocytic cells in H3N2-infected lungs. In contrast, serious lung damage, such as alveolar capillary hyperemia, edema, alveolar collapse, and lymphocytic infiltrations was observed in H5N1-infected group. Furthermore, neural system changes were present in the brains of H5N1-infected pikas.ConclusionsSAα2,6Gal receptors are extensively present in many of the tissues and organs in wild plateau pika, whereas SA2,3Gal-linked receptors are dominant on the tracheal epithelial cells. H1N1, H3N2, and H5N1 were able to infect pika and caused different degrees of pathogenic changes in the lungs. Altogether, these results suggest that wild pika has the potential to be a host for different subtypes of influenza A viruses.Electronic supplementary materialThe online version of this article (doi:10.1186/s12985-015-0290-8) contains supplementary material, which is available to authorized users.

Intermittent cold exposure results in visceral adipose tissue “browning” in the plateau pika (Ochotona curzoniae)

The plateau pika has developed tolerance to cold and hypoxia in order to adapt to living in the extreme environment of the Qinghai-Tibetan Plateau. One mammalian mechanism for cold adaptation is thermogenesis by brown adipose tissue (BAT), but the degree to which pika exploits this mechanism or how it may be modified by the additional stresses of high altitude is not known. Intermittent Cold Exposure (ICE) is an approachable method to study cold adaptation in rodents. To investigate the role of adipose tissue in the adaptation of pika to cold temperatures, we have studied pika during ICE. We find that pika kept in warm temperatures has little classical brown fat, but “browning” of white adipose tissues is observed rapidly upon cold exposure. This is demonstrated by the increased expression of several markers of brown fat differentiation including uncoupling protein 1 (UCP-1). Surprisingly, this occurs mainly in visceral rather than epididymal adipose tissue. In addition, ICE increases the expression of several general adipose differentiation markers at both the mRNA and protein levels. These substantial changes in the distribution of fat are accomplished without changes in weight or blood levels of glucose and triglycerides, suggesting that the adaptable changes are coordinated and self-compensated. Together, our results demonstrate that ICE promotes recruitment of BAT in pika, and unlike small mammals in at lower altitudes, pika can activate visceral WAT to adapt to cold stress without major changes overall energy balance.

The density of active burrows of plateau pika in relation to biomass allocation in the alpine meadow ecosystems of the Tibetan Plateau

Understanding the relationships between plateau pika population and plants biomass is essential for improving small herbivores management in alpine meadow ecosystems. Four degrees of active burrow densities were classified to evaluate pika populations and biomass allocation interactions. Our results showed that plant composition, overall vegetation height and cover, dominant species were significantly different among four sites. Additionally, plant functional groups, above ground, below ground and total biomass, root:shoot ratios and the living roots proportion were the greatest at the zero-density site, and those at the medium-density site were the lowest. We postulate that pika activities may not be the cause of the differences, but a symptom of grassland degradation. Further, pika population fluctuations should be monitored, and when the population exceeds the economic threshold of low-density (110 pikas or/and 512 active burrows ha−1) or reaches high-density (200 pikas or/and 1360 active burrows ha−1), integrated management strategies should be implemented to protect damage.

チベット高原三江源地域高山放牧地における クチグロナキウサギ（Ochotona curzoniae）の 生息密度と植生および土壌理化学性との関係

チベット高原三江源地域高山放牧地における クチグロナキウサギ（Ochotona curzoniae）の 生息密度と植生および土壌理化学性との関係

高原鼠兔有效洞穴密度对高山嵩草群落及其主要种群空间分布特征的影响

高原鼠兔有效洞穴密度对高山嵩草群落及其主要种群空间分布特征的影响

Factors Affecting Nest Success of the Oriental Skylark on the Tibetan Plateau

Abstract The Oriental Skylark Alauda gulgula is a widespread species, but its natural history is poorly understood, especially at high altitudes. In this study, we collected breeding information on Oriental Skylarks at an altitude of 3,400 m on the northeastern part of the Tibetan Plateau and examined the effects of nest-site characteristics on nest success. The birds arrived in the study area in April, built nests in tufts of tall grass on the ground and laid their eggs (gray with brown speckles) between May and July. Clutch size averaged 3.3 eggs. Incubation was mainly by the female and lasted 12.4 days. The young left the nest when 9.7 days old. During the breeding season, individual skylarks made 2–3 breeding attempts. Nesting success, as measured by the proportion of nests from which at least one young fledged, was 41.3%. Predation accounted for the majority of failed nests. Some predators (e.g. carnivores) took both skylarks and Mountain Pikas Ochotona curzoniae, although the pikas, as the dominant ...

Expression of HIF-1alpha and VEGF in skeletal muscle of plateau animals in response to hypoxic stress.

Hypoxia-inducible factor-1alpha (HIF-1alpha) transcriptionally regulates expression of several target genes in protecting tissues against hypoxia. With hypoxic stress, vascular endothelial growth factor (VEGF) is a signal protein produced by cells and further contributes to improvement of vascular functions and restoring the oxygen supply to tissues. In this current study, we first hypothesized that the protein levels of HIF-1alpha and VEGF are reduced in skeletal muscles of plateau animals [China Qinghai-Tibetan plateau pikas (ochotona curzoniae)] in response to hypoxia as compared with control animals [normal lowland Sprague-Dawley (SD) rats]. We further hypothesized that HIF-1alpha plays a role in regulating expression of VEGF in skeletal muscle. Note that HIF-1alpha and VEGF were determined by using two-site immunoenzymatic assay (ELISA) methods. Our results demonstrated that hypoxic stress induced by exposure of lower O(2) (6 h) significantly increased the levels of HIF-1alpha and VEGF in the oxidative and glycolytic muscles of SD rats and pikas (P<0.05 vs. normoxic conditions). Notably, the increases in HIF-1alpha and VEGF were significantly less in pikas (P<0.05, vs. SD controls) than in SD rats. In addition, a linear relationship was observed between amplified HIF-1alpha and VEGF in oxidative muscle (r=0.76 and P<0.01) and glycolytic muscle (r=0.72 and P<0.01) and inhibiting HIF-1alpha significantly decreased expression of VEGF induced by hypoxic stress in skeletal muscles (P<0.05). Overall, our findings suggest that (1) responsiveness of HIF-1alpha and VEGF in skeletal muscles to hypoxic stress is blunted in plateau animals, and (2) HIF-1alpha has a regulatory effect on VEGF under hypoxic environment.

Evidence that the Tibetan fox is an obligate predator of the plateau pika: conservation implications

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.

Surveillance of Echinococcus isolates from Qinghai, China

Echinococcosis is highly endemic over large parts of the Qinghai–Tibet Plateau (QTP), China. Based on a large number of samples, we present data on the current presence, host distribution, and genetic diversity of Echinococcus in the Qinghai Province, located in the northeastern corner of the QTP and constituting >25% of the area of the plateau. We used 521 samples (including 451 newly collected samples and 70 samples from our previous study) from humans, yaks, sheep, goats, dogs, fox, plateau pikas, and voles in 36 counties, and genotyped them using the mitochondrial DNA marker cytochrome oxidase subunit I (cox1) gene and the maximum parsimony and Bayesian reconstruction methods. Based on the 792bp sequence matrix, we recorded 177 variable sites; 157 were parsimony-informative. A total of 105 haplotypes (H1–H105) were detected, of which H1–H15 and H90–H104, H16–H17, H18–H89, and H105 belonged to Echinococcus shiquicus, Echinococcus multilocularis, Echinococcus granulosus, and Echinococcus canadensis, respectively. Our results showed that, (i) the Qinghai Province was under a high burden of Echinococcus epidemiology; (ii) E. granulosus was the main echinococcosis threat to the local people, and the followed is E. multilocularis; (iii) there are a considerable number of haplotypes shared by domestic animals (sheep, yaks, and dogs) and humans, demonstrating the close relationship between human and domestic animals epidemiology; (iv) the threat of E. shiquicus on humans and livestock can be mostly ignored, while the infection risk of E. canadensis echinococcosis should not be neglected.

The pika and the watershed: The impact of small mammal poisoning on the ecohydrology of the Qinghai-Tibetan Plateau.

With approximately 20 % of the world's population living in its downstream watersheds, the Qinghai-Tibetan Plateau (QTP) is considered "Asia's Water Tower." However, grasslands of the QTP, where most of Asia's great rivers originate, are becoming increasingly degraded, which leads to elevated population densities of a native small mammal, the plateau pika (Ochotona curzoniae). As a result pikas have been characterized as a pest leading to wide-spread poisoning campaigns in an attempt to restore grassland quality. A contrary view is that pikas are a keystone species for biodiversity and that their burrowing activity provides a critical ecosystem service by increasing the infiltration rate of water, hence reducing overland flow. We demonstrate that poisoning plateau pikas significantly reduces infiltration rate of water across the QTP creating the potential for watershed-level impacts. Our results demonstrate the importance of burrowing mammals as ecosystem engineers, particularly with regard to their influence on hydrological functioning.

A random forest approach for predicting the presence of Echinococcus multilocularis intermediate host Ochotona spp. presence in relation to landscape characteristics in western China

Understanding distribution patterns of hosts implicated in the transmission of zoonotic disease remains a key goal of parasitology. Here, random forests are employed to model spatial patterns of the presence of the plateau pika (Ochotona spp.) small mammal intermediate host for the parasitic tapeworm Echinococcus multilocularis which is responsible for a significant burden of human zoonoses in western China. Landsat ETM + satellite imagery and digital elevation model data were utilized to generate quantified measures of environmental characteristics across a study area in Sichuan Province, China. Land cover maps were generated identifying the distribution of specific land cover types, with landscape metrics employed to describe the spatial organisation of land cover patches. Random forests were used to model spatial patterns of Ochotona spp. presence, enabling the relative importance of the environmental characteristics in relation to Ochotona spp. presence to be ranked. An index of habitat aggregation was identified as the most important variable in influencing Ochotona spp. presence, with area of degraded grassland the most important land cover class variable. 71% of the variance in Ochotona spp. presence was explained, with a 90.98% accuracy rate as determined by ‘out-of-bag’ error assessment. Identification of the environmental characteristics influencing Ochotona spp. presence enables us to better understand distribution patterns of hosts implicated in the transmission of Em. The predictive mapping of this Em host enables the identification of human populations at increased risk of infection, enabling preventative strategies to be adopted.

Lowly pathogenic avian influenza (H9N2) infection in Plateau pika (Ochotona curzoniae), Qinghai Lake, China

Avian influenza viruses (AIVs) are globally important contagions. Several domestic mammals can be infected with AIVs and may play important roles in the adaptation and transmission of these viruses in mammals, although the roles of wild mammals in the natural ecology of AIVs are not yet clear. Here, we performed a serological survey of apparently healthy Plateau pikas at Qinghai Lake in China to assess the prevalence of exposure to AIVs. Ninety-two of 293 (31%) of wild Plateau pikas possessed serum antibodies against a lowly pathogenic avian influenza (LPAI) H9N2 virus. Experimental inoculation of Plateau pikas with a LPAI H9N2 virus resulted in productive viral replication in respiratory tissues without prior adaptation. Our findings suggest that Plateau pikas represent a natural mammalian host to H9N2 AIVs and may play a role in the ongoing circulation of H9N2 viruses at Qinghai Lake in China. Surveillance for AIV infection in Plateau pika populations and other mammals that have close contact with the Plateau pikas should be considered.

Postnatal ontogenetic size and shape changes in the craniums of plateau pika and woolly hare (Mammalia: Lagomorpha).

In the present study, postnatal ontogenetic size and shape changes in the cranium of two lagomorph species, the plateau pika (Ochotona curzoniae) and woolly hare (Lepus oiostolus), were investigated by geometric morphometrics. The ontogenetic size and shape changes of their cranium exhibited different growth patterns in response to similar environmental pressures on the Qinghai-Tibetan Plateau. The overall size change in the cranium of the plateau pika was slower than that of the woolly hare. The percentage of ontogenetic shape variance explained by size in the woolly hare was greater than that in the plateau pika. The overall shape of the cranium was narrowed in both species, and morphological components in relation to neural maturity showed negative allometry, while those responsible for muscular development showed isometric or positive allometry. The most remarkable shape variations in the plateau pika were associated with food acquisition (temporalis development), though other remarkable shape variations in the incisive and palatal foramen in the ventral view were also observed. The most important shape change in the woolly hare was demonstrated by the elongation of the nasal bones, expansion of the supra-orbital process and shape variation of the neurocranium.

チベット高原三江源地域高山放牧地における クチグロナキウサギ（Ochotona curzoniae ）の生息密度と植生との関係

チベット高原三江源地域高山放牧地における クチグロナキウサギ（Ochotona curzoniae ）の生息密度と植生との関係

Identification of tannin–degrading microorganisms in the gut of plateau pikas (Ochotona curzoniae) and root voles (Microtus oeconomus)

Gut microorganisms are thought to play a role in the degradation of plant secondary metabolites in herbivores. Here, we examined the presence of tannin–degrading microorganisms in the gut of two herbivores, plateau pikas (Ochotona curzoniae) and root voles (Microtus oeconomus). Tannase activity in the feces of wild plateau pikas and root voles increased from June to August, corresponding to the increase in condensed and hydrolyzable tannin concentrations in plants during this period. Using intragastric tannic acid infusion, we found that tannase activities were significantly higher following administration of three concentrations of tannic acid than that in the control group for root voles. In contrast, for plateau pikas, animals administered tannic acid exhibited lower tannase activity in low–dose and high–dose groups than that in the control group. Tannase activities in root voles were higher than those in plateau pikas among different months and in different tannic acid infusion groups. Three tannin–degrading anaerobic strains were isolated from the cecum of plateau pikas (termed A1, A2, and A3) and root voles (termed M1, M2, and M3). 16 s rDNA sequencing assigned isolates A1 and M1 to the genus Enterobacter, A2 and M2 to the genus Shigella, and A3 and M3 to the genus Staphylococcus. These data provided the first evidence of microorganisms with tannin–degrading activity in the gut of plateau pikas and root voles. We speculated that both animals could degrade tannins in the gut, but that root voles would have a greater ability to process tannins than plateau pikas.