From biology to management of Savi's pine vole (Microtus savii)

Savi's pine vole (Microtus savii) is a rodent species of the Cricetidae family, inhabiting southern European agroecosystems. It is considered to be the main cause of rodent‐attributed damage in Italy. To achieve an effective management, detailed knowledge of this species is needed. However, the available information about this species is fragmentary and incomplete. In this paper, the existing knowledge of Savi's pine vole taxonomy, reproduction, population dynamics, habitat and food preferences is reviewed in order to organise available information and identify priority areas of future research. Some of the changes in farming practices that have occurred in recent decades may have increased the impact of Savi's pine vole populations in crop fields. To manage this pest species effectively, an integrated strategy is recommended (involving habitat management, trapping and, when appropriate, the use of rodenticides). The apparent lack of cyclical population outbreaks and the relatively small litter size and long gestation and interpartum period of this species suggest that it could be more manageable than other vole species, while its strict herbivorous diet, stable population size in open habitats and wide distribution seem to indicate it as an ideal model species for risk assessment studies. © 2015 Society of Chemical Industry     

增效溴敌隆对几种害鼠的毒杀作用

本文涉及一种抗凝血增效灭鼠剂的研制和应用.该灭鼠剂是以溴敌隆为主剂、以双氯芬酸钠、丙三醇等为辅剂,可制成液剂和粉剂.经生物测定表明,对大白鼠、小白鼠、褐家鼠、大仓鼠和布氏田鼠均有很好的毒效,毒杀率基本达到100％,且适口性良好.现场试验对褐家鼠防效达96％以上.该药中溴敌隆含量为0.002％时,防效与0.005％溴敌隆相当起到了增效的作用,降低了成本,减少了环境污染,保证了人畜安全.     

Zanthoxylum piperitum (DC), a potential feeding deterrent for mammals: studies with Microtus ochrogaster (Wagner)

Total extract from the fruit of Szechuan pepper (Zanthoxylum piperitum DC), the volatile components of the extract and a non‐volatile fraction containing alkylamides (NVA fraction) are feeding deterrents for rats. The present study investigated the effectiveness of these natural repellents in prairie voles (Microtus ochrogaster Wagner). Two‐choice feeding trials were conducted during which food‐deprived voles were offered choices between oat‐bran wafers. In Experiment 1, 10 voles were given three sets of feeding trials, each 2 h long. Baseline consumption was established during the first set of two trials by offering a choice between two oat‐bran wafers dipped in ethanol, the control solvent. During the second set of two trials the voles were given a choice between an oat‐bran wafer dipped in ethanol and a wafer dipped in Zanthoxylum extract. During the third set the voles were given a choice between a wafer served on top of a screened dish containing a sample of ethanol and a wafer served on top of a dish containing a sample of extract. In this manner the voles were exposed to volatile compounds emanating from the extract but could not contact it. Wafers dipped in extract were almost completely avoided. The volatile components of extract also significantly reduced food intake. In Experiment 2, habituation to the volatile constituents of extract was examined in 16 Zanthoxylum‐naïve voles. Baseline consumption was established by offering two wafers served on top of screened dishes containing ethanol. This was followed by twelve tests during which a choice between a wafer served above a sample of ethanol and a wafer served above a sample of extract was given. The voles failed to habituate to the volatile components of extract, consistently consuming less of the wafers served above extract. In Experiment 3 a dose‐response curve to Zanthoxylum extract was established, using 12 stimulus‐naïve voles. After baseline consumption was established, the animals were given two tests each, presenting a choice between a control wafer and a wafer dipped in a dilution of extract (0.001–100 g liter^?1). Only concentrations of 10 and 100 g liter^?1 reduced food intake. In Experiment 4 the effects of the non‐volatile fraction of extract were compared to those of whole extract. Vegetable oil was used as solvent. Eight stimulus‐naïve voles were given two tests with a choice between an oil‐dipped and an extract‐dipped wafer. A second group of eight voles received two tests with a choice between an oil‐dipped and NVA‐dipped wafer. Extract‐dipped wafers were avoided, but the NVA fraction had no effect on food consumption. Copyright © 2004 Society of Chemical Industry     

Forecasting vole population outbreaks in forest plantations: The rise and fall of a major mammalian pest

Voles of the genera Microtus and Myodes feed on tree seedlings planted on cutover forest land in temperate and boreal forests of North America and Eurasia. This damage may have serious economic implications as well as limit regeneration of appropriate tree species in certain forest ecosystems. Prediction of vole population outbreaks and feeding damage to forest plantations, across even a limited geographic range, has yet to be achieved in North America. Thus, a major objective was a detailed analysis of changes in population dynamics of long-tailed voles (Microtus longicaudus), and to test three hypotheses (H) that vole populations would: (H₁) rise and fall in accordance with the abundance of herbaceous plants (grasses and forbs) during early vegetative succession after forest harvesting, (H₂) be positively associated with grass-seeded sites; and (H₃) incidence of feeding damage to seedlings would be positively associated with vole abundance. Voles were live-trapped for 6 years (2004–2009) from the time of harvesting on intensive sites, as well as surveyed over a range of extensive sites. Population numbers were related to habitat characteristics and tree damage in young forest plantations near Golden, British Columbia, Canada.     

甘肃鼢鼠与根田鼠的犁鼻器和副嗅球结构研究

为了探讨地下鼠犁鼻系统与地面鼠的差异及其与地面鼠嗅觉功能相适应的特点,用组织学方法对甘肃鼢鼠(Myospalax cansus)与根田鼠(Microtus oeconomus)的副嗅球和犁鼻器结构并进行了差异性研究。结果表明,2种鼠的犁鼻器均位于鼻腔前端鼻中隔基部两侧,呈管状;甘肃鼢鼠犁鼻上皮厚度、副嗅球颗粒细胞和僧帽细胞带宽比根田鼠发达;甘肃鼢鼠犁鼻器、副嗅球的性二型分化比根田鼠显著。2种鼠各自犁鼻器和副嗅球的形态有一定的对应关系,甘肃鼢鼠犁鼻上皮、副嗅球厚而短;根田鼠犁鼻上皮、副嗅球薄而长。这种对应关系可能与犁鼻器和副嗅球之间存在着神经投射有关。     

中国东方田鼠生物生态学研究进展

采用4亚种分类系统(东北亚种Microtusfortispelliceus、指名亚种M.f.fortis、长江亚种M.f.calamorum和福建亚种M.f.fujiandensis),对中国东方田鼠(M.fortis)生物生态学研究现状进行了综述。①中国东方田鼠的分类地位有争议,乌苏里江亚种(M.f.pelliceus)是否属于东方田鼠仍有待进一步研究;迄今为止,对长江亚种进行的研究较多,而对其它亚种的研究甚少。②从南部到北部都有东方田鼠分布,多栖息在低海拔地区,偏爱湿地生境。③该鼠主要以草本植物的绿色部分为食,为农林害鼠,化学防治东方田鼠采用敌鼠钠盐和复方灭鼠剂88-1对人畜比较安全,汛期还可结合物理方法对迁入洞庭湖稻田区的东方田鼠进行灭杀。④从南到北胎仔数、怀孕率有增加的趋势,繁殖期逐渐缩短。⑤沼泽扩展导致东方田鼠种群数量增加,而湖面围垦致使其数量下降。⑥该鼠昼夜均活动,但季节间存在差异,有季节性迁移行为,雌雄鼠均具有杀幼行为。     

应用Leslie矩阵对布氏田鼠种群数量的模拟分析

采用Leslie矩阵对内蒙古太仆寺旗草原的布氏田鼠作了种群动态模拟分析.结果表明:①该模型数值模拟的准确率达到87.7%.②矩阵特征值λ既表达了在调查时段种群达到稳定增长状态的周限增长率,又可作为衡量种群变动趋势的指标:当λ＞1.232时布氏田鼠种群处于上升期,当λ趋于1.232时种群处于高峰期,当λ＜1时种群处于下降期.③不同增长期的年龄结构与繁殖率的差异显著,在种群上升期,幼鼠比例明显高于高峰期和下降期.④在上升期,繁殖率为关键因子;在高峰期和下降期的关键因子是存活率.     

Effect of ENSO-driven precipitation on population irruptions of the Yangtze vole Microtus fortis calamorum in the Dongting Lake region of China

The Yangtze vole (Microtus fortis Buechner, 1889) is a small herbivore species that inhabits lake beaches in the Dongting Lake region along the Yangtze River in Southern China. Its population shows strong oscillations during the wet season due to summer precipitation-induced immigration away from the lake into adjacent rice fields. The effect of El Niño-Southern Oscillation-driven precipitation on population abundance and growth of the vole species is not fully understood. We undertook an analysis of the combined data of 4 time series covering 1981–2006 from 4 different sites and a separate analysis on a single time series (1981–2006) from one site. Our results demonstrate that a dual effect of El Niño-Southern Oscillation-driven precipitation on the population abundance of voles is time-dependent: precipitation in the current year has a positive effect, whereas precipitation in the previous year has a negative effect. The dual effect of precipitation on vole population is well explained by the unique interactions among vole population, precipitation water level and the lake beach habitat around Dongting Lake. We found that drier than average weather of the previous year benefited voles because their breeding habitats, lake beaches, were exposed for long stretches of time. Wet weather was found to increase the number of voles inhabiting rice fields because as the water level of the lake rose they were forced from beaches into surrounding rice fields. Summer precipitation in the Dongting Lake region was found to be positively associated with the sea surface temperature (SST) of the eastern tropical Pacific Ocean of the previous year and winter SST and spring SST of the current year. Annual rates of increase in the vole population of the reconstructed time series are negatively associated with the vole abundance and autumn precipitation of the previous year and winter precipitation of the current years. These results suggest that both extrinsic and density-dependent intrinsic factors may affect population dynamics of the Yangtze voles.     

封闭群东方田鼠染色体制备中刀豆素的应用技术研究

在按常规技术制备东方田鼠染色体前24h，腹腔注射20μg／g体重的刀豆素，并记数随机显微视野中，分裂相的多少，发现用刀豆素处理的东方田鼠骨髓细胞中，分裂相大大多于未经刀豆素处理的东方田鼠。按此剂量处理的东方田鼠，染色体形态与未经刀豆素处理的东方田鼠没有明显的差别。因此，刀豆素的处理便于对东方田鼠染色体的分析。     

Hepatitis E virus in Common voles (Microtus arvalis) from an urban environment,Hungary: Discovery of a Cricetidae‐specific genotype of Orthohepevirus C

Hepatitis E virus is a major causative agent of acute hepatitis worldwide. Despite its zoonotic potential, there is limited information about the natural chain of hepevirus infection in wildlife, and the potential reservoir species. In this study, we performed a HEV survey by heminested RT‐PCR on rodent samples from an urban environment (in the city of Pécs, Hungary) and investigated the prevalence of the virus among these native rodent species (Apodemus agrarius, Apodemus flavicollis, Apodemus sylvaticus, Microtus arvalis and Myodes glareolus). HEV was detected exclusively in Common voles (M. arvalis), in 10.2% of screened voles, and 3.2% of all investigated samples from all species. Based on the phylogenetic analysis, our strain showed the closest homology with European Orthohepevirus C strains detected previously in faecal samples of birds of prey and Red fox, supporting the possibility of the dietary origin of these strains. In addition, our samples showed close phylogenetic relation with a South American strain detected in Necromys lasiurus (Cricetidae), but separated clearly from other Muridae‐associated strains, suggesting the presence of a Cricetidae‐specific genotype in Europe and South‐America. Based on these results, we hypothesize the reservoir role of M. arvalis rodents for the European Cricetidae‐specific Orthohepevirus C genotype.