Microtus Gregalis Research Articles

Is the enamel differentiation quotient (SDQ) of the narrow-headed vole (Microtus gregalis) useful for Pleistocene biostratigraphy?

In order to explore temporal trends of morphological variation in the narrow-headed vole (Microtus gregalis) traditional morphometric methods were used to quantify enamel differentiation quotient (SDQ), tooth size (L) and tooth proportion (A/L) in over 800 first lower molars from two sites in Central Europe. Our results suggest that SDQ values in late Middle Pleistocene assemblages are significantly lower than those in Late Pleistocene populations. A greater chronostratigraphic variation in SDQ occurs across the Late Pleistocene compared to the late Middle Pleistocene. This probably indicates repeated extinctions and re-colonisations, most likely from Eastern Europe or Asia, during MIS 3 and MIS 2. However, it is unclear whether this pattern represents a local phenomenon or whether the SDQ changes took place across a large geographical scale. Further studies on fossil and recent populations of the species are necessary to identify the determinants of SDQ variation in Microtus gregalis and to confirm the usefulness of the index for the Pleistocene stratigraphy.

Cold-climate rodent indicators for the Late Pleistocene of Central Iberia: New data from the Buena Pinta Cave (Pinilla del Valle, Madrid Region, Spain)

In the Iberian Peninsula, the Late Pleistocene record of small mammal indicators of cold climates is largely restricted to two sets of sites at the eastern and western ends of the Pyrenees. Some assemblages from other sites at the Peninsular centre have, however, recently yielded such taxa. This work describes the remains of three such rodent species from the Buena Pinta Cave, a site in the Sierra de Guadarrama mountains in the Spanish Central System. Excavation campaigns in the cave have taken place every summer since 2003. Thermoluminescence analyses of sediments from levels 2–5 of the site suggest an age corresponding to the middle of the Late Pleistocene, within Marine Isotope Stage 4 or the beginning of Marine Isotope Stage 3. Sieve-washing and picking out of the small fossils contained in the sediments of levels 2–5 yielded several thousand small mammal teeth and other remains, dominated by Microtus arvalis. Smaller numbers of remains belonging to other rodents typical of cold climates were also identified, such as Microtus oeconomus, Microtus gregalis and Chionomys nivalis. Thus, the small mammal record of the Buena Pinta Cave shows that rodent indicators of cold climates reached the centre of the Iberian Peninsula during the mid-Late Pleistocene, i.e., well before the Last Glacial Maximum. These findings represent one of the southernmost Pleistocene records for M. oeconomus in Europe, and the most southerly for M. gregalis.

Changes in the morphology and morphological diversity of the first lower molar of narrow-headed voles (Microtus gregalis, Arvicolinae, Rodentia) from northeastern European Russia since the Late Pleistocene

Abstract We studied morphotypic traits and dimensions of the first lower molar (m1) of recent and Late Pleistocene narrow-headed voles (20 samples) from localities of northeastern European Russia (the NE Russian Plain, Timan Ridge, and northern Ural Mountains). A high diversity of m1 morphotypes was found, especially among voles of the Late Pleistocene. The shape of the anteroconid and the size of the m1 varied independently from each other. No stable time trends in the proportions of “archaic” gregaloid and “advanced” microtid morphotypes of m1 for the last 50 ka were found. The morphotypical traits of only the oldest samples dated to the Early Valdaian (Laya, MIS 4) or late Sula (Mezin, end of MIS 5) were noticeably different from others. Our results do not support the hypothesis that climate changes in the Late Pleistocene–Holocene are correlated with the morphology (including morphotypic diversity) of the anteroconid of the first lower molar. Recent and Late Holocene voles inhabiting tundra are not similar morphologically to the Late Pleistocene animals in the region.

Middle Pleistocene voles and lemmings (Rodentia: Arvicolinae) from Za Hájovnou Cave (Javoříčko Karst)

Remains of fossil voles and lemmings (Arvicolinae) in two profiles in Za Hajovnou Cave, ZH P-2 (Komin I) and ZH P-8b (Narozeninova chodba, Area A), were preliminarily investigated. The assemblages from ZH P-2 layers 7 and 6 indicate Q3 biozone. Layer 7 may have been deposited during the lower part of the Saalian stage (probably MIS 8 and MIS 7) whereas layer 6 is also of the Saalian age but it originated later (probably MIS 6). The assemblage composition reflects the climatic inconsistency within layers 7 and 6, with a significant increase in number of elements typical for open dry environments, e.g. Microtus (Stenocranius) gregalis; however some other taxa indicating humid or warmer habitats nearby e.g. Microtus (Pallasiinus) oeconomus and Clethrionomys glareolus, were also reported. Although the voles in ZH P-8b, layers 2a, 2b and 2a, 2b (0-20 cm), belong to extant representatives, remains of Middle Pleistocene Ursus cf. deningeri enable assignation to Q3 biozone. We presuppose that layer 2a, 2b was deposited most probably within the upper part of the Holsteinian s.l. (probably MIS 9a). This assumption is supported not only by 230 Th/U dating of slightly younger (267 ± 3 ka) sinter from the upper part of the equivalent layer 2a within ZH P-5 but also by the finding that layer 2a, 2b was deposited under relatively warm and humid climatic conditions in an open woodland environment which was documented by the presence of C. glareolus (total absence of lemmings), M. (Stenocranius) gregalis and M. (Pallasiinus) oeconomus. Overlying layers 1c(a) and 1c(b) were deposited most probably during a relatively warm period between the Middle and Late Pleistocene (Q3 or Q4 biozone). A more precise estimate of the biostratigraphical position of the deposits is impossible because of both the limited amount of fossil material available and gravitional redeposition during the Holocene. ■ Rodentia, biostratigraphy, palaeoecology, Za Hajovnou Cave, Javořicko Karst, Moravia.

Shifts in activity patterns ofMicrotus gregalis: a role of competition or temperature?

Abstract Although temporal partitioning has long been viewed as a valid mechanism in reducing competition, direct field evidence is rare, and the temporal niche is often considered less important than other factors in promoting coexistence. Furthermore, the relative importance of biotic and abiotic factors in shaping diel activity patterns of animals is poorly understood. We conducted controlled experiments in a little-studied area (Hulunbuir meadow steppe, China) to explore the effects of presence of a larger species, Spermophilus dauricus, and ambient temperature in shaping diel activity patterns of Microtus gregalis. Our results suggest that although interference competition existed between S. dauricus and M. gregalis, the presence of S. dauricus did not significantly affect the diel activity patterns of M. gregalis (P > 0.05). Timing of activity of M. gregalis, however, was always significantly correlated with ambient temperature (P < 0.001). As winter approached, ambient temperature appeared to be a ...

Phylogeography of the narrow-headed vole Lasiopodomys (Stenocranius ) gregalis (Cricetidae, Rodentia) inferred from mitochondrial cytochrome b sequences: an echo of Pleistocene prosperity

A species-wide phylogeographic study of the narrow-headed vole Lasiopodomys (Stenocranius) gregalis was performed using the mitochondrial (mt) cytochrome b gene. We examined 164 specimens from 50 localities throughout the species distribution range. Phylogeographic pattern clearly demonstrates the division into four major mtDNA lineages with further subdivision. The level of genetic differentiation between them was found to be extremely high even for the species level: about 6–11%. The most striking result of our study is extremely high mutation rate of cytb in L. gregalis. Our estimates suggested its value of 3.1 × 10−5 that is an order of magnitude higher than previous estimates for Microtus species. The mean estimated time of basal differentiation of the narrow-headed vole is about 0.8 Mya. This time estimate is congruent with the known paleontological record. The greatest mitochondrial diversity is found in Southern Siberia where all four lineages occur; therewith, three of them are distributed exclusively in that area. The lineage that is distributed in south-eastern Transbaikalia is the earliest derivate and exhibits the highest genetic divergence from all the others (11%). It is quite probable that with further research, this lineage will turn out to represent a cryptic species. Spatial patterns of genetic variation in populations of the narrow-headed vole within the largest mt lineage indicate the normal or stepping stone model of dispersal to the north and south-west from the Altay region in Middle Pleistocene. Both paleontological data and genetic diversity estimates suggest that this species was very successful during most of the Pleistocene, and we propose that climate humidification and wide advance of tree vegetation at the Pleistocene–Holocene boundary promoted range decrease and fragmentation for this typical member of tundra-steppe faunistic complex. However, we still observe high genetic diversity within isolated fragments of the range.

Small mammal fauna as an evidence of environmental dynamics in the Holocene of Ukrainian area

In Ukraine, changes in composition, morphology and spatial distribution of small mammals provide insight regarding environmental dynamics of the Holocene. During an early stage, conditions were rather close to the Pleistocene ones. Microtus gregalis, Microtus oeconomus, and Lagurus lagurus still dominated but were represented by small-sized forms when compared to the Late Pleistocene. During a middle stage, meadow-steppe elements prevailed; bunodont rodents (hamsters, ground squirrels, birch mice, mice) dominated voles. A late stage was characterised by plenty and widespread forest species. These stages most adequately reflect situation in river valleys, where taphocenoses considered in this paper were mainly connected. Increasing fluvial activity of wet epochs formed open landscapes even in small valleys, and decreasing flow during arid time spans allowed valleys to be overgrown with forest. On watersheds, the same climatic changes caused the opposite effects. Taking this into account, the mid-faunal stage should be dated as Atlantic, despite its seemingly forestless character. The taphocenoses of this stage are contemporary with valley incisions. The early stage, corresponding to relatively high base level position, should be dated as Preboreal–Boreal, and the late stage as Subboreal–Subatlantic.Some tundra-steppe species were stable through all the stages. Ochotona pusilla and Spermophilus superciliosus persisted almost until present. O. pusilla, differing from its Pleistocene distribution, was confined to rocky biotopes, evidently, due to a change of herbage. A special case of range dynamics is represented by Spermophilus pygmaeus. A population of this Left Bank species had come to be isolated on the Dnieper Right Bank, seemingly, as a result of the Dnieper channel change.

Small rodents in the shrub tundra of Yamal (Russia): Density dependence in habitat use?

Northern small rodents are well known for their population cycles which represent a key process for the functioning of arctic and boreal ecosystems. Habitat use often changes in the course of the cycle. Higher densities can either lead to spill-over into secondary habitats or to increased habitat specificity because of interspecific competition. Here we investigate whether voles in the shrub tundra of southern Yamal exhibit density dependent habitat use. Voles were trapped at the Erkuta Tundra Monitoring Site (N 68.2°, E 69.2°) in three characteristic habitats over five years covering all phases of the population cycle. Our analyses focused on the two most numerous species Microtus gregalis (52% of individuals caught) and M. middendorffii (36%). A small-scale spill-over effect was observed for M. gregalis, which increasingly used the open habitat adjacent to their preferred willow thickets at high abundance. At a larger scale no such effect was observed for the two Microtus species – a result which is explained by the overall moderate densities of voles and the large spatial extent of the primary habitat of M. middendorffii: moist moss dwarf shrub tundra.

Morphological and genetic variation of narrow-headed voles Lasiopodomys gregalis from South-East Transbaikalia

Morphological and genetic variation of narrow-headed voles Lasiopodomys gregalis from South-East Transbaikalia

Vertebrates from the Middle Pleistocene locality Lysa Gora 1 in Ukraine

A vertebrate fauna from the new Middle Pleistocene locality Lysa Gora 1 of Southern Ukraine (Zaporizhya region) is described. The locality has yielded an assemblage of at least 11 taxa of bony fishes (Cypriniformes, Siluriformes, Esociformes, Perciformes) and small mammals (Lagomorpha – 2 taxa, Rodentia – 11 species). The species composition of Arvicolidae, particularly the presence of Lagurus transiens, Eolagurus luteus, Arvicola mosbachensis, Microtus (Terricola) arvalidens, and Microtus (Stenocranius) gregalis, as well as the structure of the fauna, suggests Middle Pleistocene age (MQR 4, MIS 13-12, Early Toringian). New data on the paleoecology of the locality and taxonomy/phylogeny of selected taxa are discussed.

Ontogenetic variation in occlusal shape of evergrowing molars in voles: An intravital study in Microtus gregalis (Arvicolinae, Rodentia)

In order to reveal patterns of ontogenetic change in occlusal shape of evergrowing molars in arvicolines, an intravital tooth printing method was applied to 20 individuals of Microtus gregalis born in captivity. Complexity patterns of the first lower molar were assessed by morphotype analysis of the anteroconid complex. Morphotype dental patterns were monitored using tooth prints at 0.5, 1, 2, 3 months of age, and postmortem. Ontogenetic changes in molar complexity and bilateral symmetry among right and left molars of the same individual during the process of tooth wear were assessed. Our results suggested that morphotype dental patterns could not be clearly established in half-month old animals due to presence of juvenile characters. For animals of 1 month and older, age differences in morphotype dental patterns were non-significant and negligible compared to among-individual variation. Within-individual differences among right and left molars, when present, were not related to age of an animal suggesting that bilateral asymmetry of morphotype dental pattern could be regarded as inherent characteristic of an individual persisting during post-juvenile tooth wear.

Late Glacial and Holocene micromammals of northeastern Europe

Results of studying micromammalian remains from 15 cave-type localities situated in northeastern Europe are presented. Radiocarbon dating enabled to study the fauna development during six climatic phases: Bolling-Allerod, Younger Dryas, Preboreal, Boreal, Subboreal and Subatlantic. Assemblages of Bolling-Allerod with predominance of Siberian lemming are followed by communities of the Younger Dryas. These are dominated by xerophilous species: narrow-headed vole in the Subpolar Urals, and collared lemming in the rest of region. A considerable proportion of tundra species remained in communities during the Preboreal. A drastic transformation of micromammalian communities from the tundra-steppe to forest has occurred after 9000 BP, and possibly before 8500 BP. The modern-like fauna was formed during the Subatlantic.

Multilocus phylogeny of arvicoline voles (Arvicolini, Rodentia) shows small tree terrace size

We combined mitochondrial (cyb, control region, coi, nd4) and nuclear (irbp, ghr, sry, lcat) DNA sequence data to infer phylogenetic relationships of arvicoline voles. The concatenated supermatrix contained 72.8 % of missing data. From this dataset, Bayesian inference showed close relationships of Arvicola and Chionomys, Proedromys with Lasiopodomys and Microtus gregalis, Phaiomys with Neodon and M. clarkei. Genus Microtus formed a supported group with Blanfordimys and N. juldaschi. The gene partition taxon sets were explained in the multilocus phylogeny in such a way that the resulting Bayesian inference tree represented a unique solution on a terrace in the tree space. This means that although the supermatrix contained a large proportion of missing data, it was informative in retrieving a phylogeny with a unique optimality score, tree likelihood.

Remains of small mammals from fossil burrows in the archaeological Pleistocene site Ihrovytsya (western Ukraine)

Abstract. This paper presents the results of study on fossil materials collected from the archaeological site Ihrovytsya I (western Ukraine). The small mammals remains were accumulated inside fossil animal burrows. Six taxa of rodents (Spermophilus sp., Microtus gregalis, Microtus arvalis/gregalis, Microtus (Terricola) sp., Dicrostonyx gulielmi and Lemmus lemmus) and one taxon of lagomorphs (Ochotona pusilla) were identified among the collected bone remains. Species representation indicates a typical steppe-tundra community related with a cool climatic period. The age of the assemblage is confirmed by their position in a stratified and previously geologically investigated profile and should be connected with early part of the Last Glaciation (MIS 5a-5b or early part of MIS 4).

Late Glacial and Holocene small mammals of the Timan Ridge (Komi Republic, Russia)

Abstract Small mammal remains from five karst-type localities situated in the Southern and Middle Timan region are presented. Three different faunal assemblages from three succeeding phases are recognized. A cryohydrophilous faunal assemblage with desman (Desmana moschata) and predominantly Siberian lemming (Lemmus sibiricus) existed during the Bolling–Allerod interstadials. During the end of Younger Dryas, the fauna changed to cryoxerophilous communities with a predominance of collared lemming (Dicrostonyx sp.) and narrow-skulled vole (Microtus gregalis). The forest fauna is typical for the Late Holocene. Until the Early Holocene, the Middle Timan region was a refugium of Dicrostonyx populations characterized by archaic molar morphology.

Decay of parental care in several generations of narrow-skulled voles (Microtus gregalis) under the conditions of vivarium breeding

Despite the growing interest to studying parentalbehavior of mammals in past decades, there are manygaps in this field so far [3, 7]. The relationshipsbetween consecutive mammalian generations aremostly studied as interactions between mother andoffspring [11]; this can be explained by the dependence of pup feeding on mothers at the beginning ofdevelopment. Males are mostly involved in competitive relationships between each other, rather than inparental care [10, 15]. However, in some mammalianspecies [11], paternal and maternal responsibilities arecomparable except for the lactation period [12].To compare the involvement of males and femalesinto parental care and to evaluate the influence of theconditions of animal breeding and rearing in captivity,a series of behavioral tests were performed with

Late Pleistocene voles (Arvicolinae, Rodentia) from the Baranica Cave (Serbia)

Late Pleistocene voles (Arvicolinae, Rodentia) from the Baranica Cave (Serbia) Baranica is a cave system situated in the south-eastern part of Serbia, four kilometers south to Knjaževac, on the right bank of the Trgoviški Timok. The investigations in Baranica were conducted from 1994 to 1997 by the Faculty of Philosophy from Belgrade and the National Museum of Knjaževac. Four geological layers of Quaternary age were recovered. The abundance of remains of both large and small mammals was noticed in the early phase of the research. In this paper, the remains of eight vole species are described: Arvicola terrestris (Linnaeus, 1758), Chionomys nivalis (Martins, 1842), Microtus (Microtus) arvalis (Pallas, 1778) and Microtus (Microtus) agrestis (Linnaeus, 1761), Microtus (Stenocranius) gregalis (Pallas, 1779), Microtus (Terricola) subterraneus (de Sélys-Longchamps, 1836), Clethrionomys glareolus (Schreber, 1780) and Lagurus lagurus (Pallas, 1773). Among them, steppe and open area inhabitants prevail. Based on the evolutionary level and dimensions of the Arvicola terrestris molars, as well as the overall characteristics of the fauna, it was concluded that the deposits were formed in the last glacial period of the Late Pleistocene. These conclusions are rather consistent with the absolute dating of large mammal bones (23.520 ± 110 B.P. for Layer 2 and 35.780 ± 320 B.P. for Layer 4).

Quaternary rodent and insect faunas of the Urals and Western Siberia: Connection between Europe and Asia

Abstract The biogeographic groups of rodent (arvicoline) and beetle species in the modern fauna of the Urals and Western Siberia based on the longitudinal patterns of their present-day distribution are established. Occurrence of species of the Transpalearctic, West Palearctic (European), East-Palearctic, and Central-Palearctic faunal groups is estimated at different stages of the Late Quaternary development of the present-day fauna of the region. The border between the European and East-Palearctic faunal groups represents a vast territory where the ranges of the species included in those groups intersect. The border territory includes the Ural Mountains and the lowlands lying west and east of it (the East-European Plain and the West Siberian Plain). The biomes of those territories represent the North-Eurasian corridors providing migrations of species from the different faunal complexes in the west–east, east–west, and north–south directions. The importance of the study area for faunal correlations throughout the continent is determined by presence of the key arvicoline taxa traditionally used for correlation purposes (taxa Dicrostonyx, Lagurus, Microtus gregalis), and by the gradual change in faunal composition along the latitudinal gradient of environment at any given stage of the Quaternary. Transzonal faunal correlations within the Urals and Western Siberia integrating the evolutionary morphological studies of the key taxa and assessment of the faunal successions may serve as a basis for Trans-Eurasian correlation.

New data on the distribution of hantavirus in rodent populations in Siberia

New foci of hantavirus infection were found in Altai and Krasnoyarsk krais, in Novosibirsk, Kemerovo, and Tomsk oblasts, and Altai Republic. It is shown that hantaviruses are distributed in all landscape zones and subzones. The bank vole, the gray red-backed vole, the northern red-backed vole, the narrow-headed vole, the field vole, the root vole, the steppe lemming, and the Korean field and striped mice.

Upper paleolithic mammal fauna of the Baikal region, east Siberia (new data)

A representative mammal fauna attributable to the Karginian Interstadial (MIS 3, 36 000–23 000 BP) has been found for the first time in the Fore-Baikalian region. The faunal remains were recovered from Gerasimov’s and Bol’shoi Naryn Paleolithic sites in 2003–2008. Zooarchaeological investigations revealed 51 mammal species in the region, dominated by horse Equus sp., steppe lemming Lagurus lagurus, narrow-sculled vole Microtus gregalis and North-Siberian vole M. cf. hyperboreus. The early humans appear to have inhabited a forest-steppe, with local patches of tundra-like landscapes. The Karginian climate was warmer and more humid than during the subsequent Sartan glacial epoch (MIS 2).