Clethrionomys Research Articles

Small mammal dynamics in snow-covered forests

AbstractIn seasonal environments, the winter months can drive the structure and dynamics of vertebrate communities. Most ecological studies have focused on species above the snow, overlooking those within the subnivium (below-snow environment). The Great Lakes region of North America is characterized by seasonal snow cover and a diverse assemblage of small mammals, both of which are changing rapidly in response to a changing climate. To study the seasonal dynamics of small mammals, we sampled communities in three forest types (hardwood, hemlock-cedar, and spruce bog) in summer and winter over 2 years. We hypothesized that seasonal differences in communities would be moderated by forest structure in summer and snow in winter. We assessed community dominance via species diversity and the abundances of deer mice (Peromyscus maniculatus), white-footed mice (P. leucopus), and southern red-backed voles (Myodes gapperi). We estimated a Community Temperature Index (CTI; a metric of the balance between warm- and cold-adapted species in a community) and tested seasonal drivers of CTI. Species diversity was highest in spruce bogs in winter due to increased species evenness, but diversity was consistent year-round in hardwood and hemlock-cedar forests due to unchanging species dominance. Spruce bogs supported the coldest CTI in summer, but CTIs converged across forest types in winter. In summer, forest structure drove CTI; in winter, colder CTIs were associated with deeper snow and a warmer subnivium. Our work reveals that snow is a critical habitat and filter for cold-adapted species that ultimately structures small mammal communities. Given rapid changes in snow conditions due to climate change, we predict continued range contractions for subnivium-adapted species.

Responsive strategies of three sympatric small rodents to the altitudinal effects on microhabitats

Abstract This study evaluated the effects of altitudinal gradients on small-rodent populations and microhabitat conditions. We selected three altitudinal bands: lowland, mid-land, and highland. We captured three small-rodent species, the striped field mouse (Apodemus agrarius), the Korean field mouse (A. peninsulae), and the red-backed vole (Myodes regulus). A. agrarius preferred microhabitats with dense ground vegetation and sparse mid-story vegetation, basal area, downed trees, and stone coverage. A. peninsulae utilized ground vegetation, overstory vegetation, and downed trees. M. regulus occupied microhabitats with abundant stone coverage and little ground vegetation coverage. Ground vegetation coverage was higher in the mid-land. The lowland was characterized by high understory vegetation, bulky downed trees, and high stone coverage. A. agrarius mostly occupied the mid-land, whereas A. peninsulae and M. regulus mainly inhabited the lowland. Our results show that each small-rodent species had its own strategy for utilizing the key habitat factors in altitudinally affected microhabitats and for reducing competition among the populations. This finding contributes to improving knowledge of the ecological altitudinal features of microhabitat conditions, as well as the altitudinal distributions and abundances of three small-rodent species.

Sperm Motility in Bank (Clethrionomys glareolus) and Northern Red-backed Voles (Cl. rutilus) Exposed to Industrial Pollution

Sperm Motility in Bank (Clethrionomys glareolus) and Northern Red-backed Voles (Cl. rutilus) Exposed to Industrial Pollution

Население мелких млекопитающих подтайги Южного Зауралья

On the basis of materials obtained using two generally accepted counting methods, data on the species composition of small mammals, the ratio of background and dominant species, the total abundance in the main groups of biotopes of the South Trans-Ural region are presented. The differences in the community structure of small mammals in the subtaiga and forest-steppe sub-zone of the South Trans-Ural region have been analysed. The paper discusses materials on the community of small mammals in the sub-taiga of the South Trans-Ural region. A brief history of the study of this group of animals is reviewed. The use of two counting methods (the ditch with pitfalls and trap-lines) allowed the most complete identification of the species composition of insectivores and rodents in the sub-taiga of the South Trans-Ural region in 2021. In terms of species, the ditch with pitfalls were more effective, with 17 species identified; trap-lines counted 13 species. The abundance of animals in 2021 was very low. In our opinion, was determined by the abnormally hot spring and summer period. On average, only rare and very rare species have been recorded in the snap-trap counts in the study area. Numerous species were absent in the average meaning regardless of the method of capture. The core of small mammals of the sub-taiga of the South Trans-Ural region consisted of species typical of humid habitats and small-leaved forests, such as the Laxmann's shrew Sorex caecutiens, common shrew S. araneus and Eurasian pygmy shrew S. minutus rodents, as well as the common vole Microtus arvalis and harvest mouse Micromys minutus (surveys using the ditch with pitfalls). The common shrew was predominant in the snap-trap counts, accounting for about 45% of the total abundance of all animals recorded. In pine forests with poor productivity and in open spaces, the total abundance of insectivores and rodents is lowest. The species composition of small mammals of the sub-taiga and forest-steppe subzone of the South Trans-Ural region are largely similar (83% of the total species). Specific features of the taiga subzone were determined by the taiga shrew Sorex isodon and Siberian chipmunk Eutamias sibiricus, unusual for the forest-steppe and herb-bunchgrass steppe subzone of the South Trans-Ural region. A characteristic feature of the sub-taiga of the South Trans-Ural region is a specific proportion of the northern red-backed vole Myodes rutilus and European bank vole M. glareolus, their abundance is comparable, or the M. glareolus predominates, which is not observed in the forest-steppe. In the sub-taiga, in the surveys using ditch with pitfalls among insectivores and rodents, the Laxmann's shrew prevailed, its share was approximately one fourth of all recorded animals, although in general the community of small mammals is polydominant, in contrast to the surveys using the trap-line method, where one species dominated – the common shrew. In 2021 (sub-taiga) as well as in 2020 (forest-steppe) the territory of the South TransUral region was characterized by a deep depression of water vole Arvicola amphibius numbers, which was completely absent in the counts.

Emergence of Ixodes scapularis (Acari: Ixodidae) in a Small Mammal Population in a Coastal Oak-Pine Forest, Maine, USA.

In the United States, surveillance has been key to tracking spatiotemporal emergence of blacklegged ticks [Ixodes scapularis Say (Ixodida:Ixodidae)] and their pathogens such as Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner (Spirochaetales: Spirochaetaceae), the agent of Lyme disease. On the Holt Research Forest in midcoastal Maine, collection of feeding ticks from live-trapped small mammal hosts allowed us to track the emergence and establishment of I. scapularis, 1989-2019. From 1989-1995, we collected only I. angustus Neumann (Ixodida: Ixodidae)(vole tick), Dermacentor variabilis Say (Ixodida: Ixodidae) (American dog tick), and I. marxi Banks (Ixodida: Ixodidae) (squirrel tick) from seven species of small mammals. The most abundant tick host was the white-footed mouse [Peromyscus leucopus Rafinesque (Rodentia:Cricetidae)] followed by the red-backed vole (Myodes gapperi Vigors (Rodentia: Cricetidae)). Emergence of I. scapularis was signaled via the appearance of subadult I. scapularis in 1996. Emergence of B. burgdorferi was signaled through its appearance in I. scapularis feeding on mice in 2005. There was a substantial increase in I. scapularis prevalence (proportion of hosts parasitized) and burdens (ticks/host) on white-footed mice and red-backed voles in 2007. The ~11-yr time-to-establishment for I. scapularis was consistent with that seen in other studies. White-footed mice comprised 65.9% of all captures and hosted 94.1% of the total I. scapularis burden. The white-footed mouse population fluctuated interannually, but did not trend up as did I. scapularis prevalence and burdens. There were concurrent declines in I. angustus and D. variabilis. We discuss these results in the broader context of regional I. scapularis range expansion.

Arboreal Behavior of the Red-Backed Vole of the Genus Myodes (Rodentia, Cricetidae) in the Northern European Taiga

Arboreal Behavior of the Red-Backed Vole of the Genus Myodes (Rodentia, Cricetidae) in the Northern European Taiga

Infestation and distribution of mites on the Yunnan red-backed vole (Eothenomys miletus) in Yunnan Province of southwest China between 2001 and 2015

Infestation and distribution of mites on the Yunnan red-backed vole (Eothenomys miletus) in Yunnan Province of southwest China between 2001 and 2015

Examining the effects of heterospecific abundance on dispersal in forest small mammals

AbstractThe effects of conspecific densities on dispersal have been well documented. However, while positive and negative density-dependent dispersal based on conspecific densities often are shown to be the result of intraspecific competition or facilitation, respectively, the effects of heterospecific densities on dispersal have been examined far less frequently. This gap in knowledge warrants investigation given the potential for the analogous processes of interspecific competition and heterospecific attraction to influence dispersal patterns and behavior. Here we use a long-term live-trapping study of deer mouse (Peromyscus maniculatus), eastern chipmunk (Tamias striatus), red-backed vole (Myodes gapperi), and jumping mice (Napaeozapus insignis and Zapus hudsonius) to examine the effects of variation in conspecific and heterospecific abundances on dispersal frequency. In terms of conspecific abundance, jumping mice were more likely to disperse from areas with fewer conspecifics, while red-backed voles and chipmunks did not respond to variation in conspecific abundances in their dispersal frequencies. While there were no statistically significant effects of variation in heterospecific abundances on dispersal frequency, some effect sizes for heterospecific abundance effects on dispersal met or exceeded those of conspecific abundances. Conspecific abundances clearly can affect dispersal by some species in this system, but the effects of heterospecific abundances on dispersal frequency are less clear. Based on effect sizes, it appears that there may be potential for heterospecific effects on dispersal by some species in the community, although the strength and causes of these relationships remain unclear.

Land-use change alters associations between personality and microhabitat selection.

Ecologists commonly assess ecological patterns at the population level, focusing on the average response of all individuals within a population, but to predict how populations will respond to land-use change we must understand how changes to habitat differentially affect individuals within a population. For example, forest management is a widespread type of land-use that impacts wildlife through the loss of key habitat features, but individuals within a population may vary in their responses to this loss due to differences in habitat selection among individuals. Specifically, intraspecific variation in habitat selection has been linked to animal personalities (i.e., consistent behavioral differences among conspecifics), but previous research has not examined whether the relationship between personality and habitat selection is influenced by land-use change. To address this knowledge gap, we tested the hypothesis that land-use change alters the association between personality and microhabitat selection in small mammals. Specifically, we investigated two main questions: (1) To what extent are personality type and microhabitat selection correlated among conspecifics? (2) Does land-use change alter individual patterns of microhabitat selection? To answer these questions, we conducted a large-scale field experiment over 4 years, contrasting unmanaged forest (control) with managed forest (two silvicultural treatments) in Maine, USA. We examined the relationships between habitat selection and personality traits in deer mice (Peromyscus maniculatus) and southern red-backed voles (Myodes gapperi). We found that personality traits were correlated with microhabitat selection at multiple spatial scales. Furthermore, land-use change altered these patterns of selection; resulting in either the loss of personality-associated selection or in novel patterns of selection in managed forests. These findings suggest that promoting structural complexity at multiple spatial scales, such as by interspersing stands of mature forest with managed stands, may maintain a variety of intraspecific habitat selection patterns and the associated ecological outcomes.

DIET COMPOSITON OF FISHERS (PEKANIA PENNANTI) REINTRODUCED ON THE OLYMPIC PENINSULA, WASHINGTON

Knowledge of diet composition can inform management strategies and efforts to recover endangered carnivore populations in vacant portions of their historic ranges. One such species, the Fisher (Pekania pennanti), was extirpated in Washington State prior to any formal documentation of its food habits in the coastal coniferous forests of western Washington. Fisher recovery efforts in Washington, based on translocating Fishers from extant populations, have been ongoing since 2008, beginning with the release of 90 Fishers on Washington's Olympic Peninsula from 2008 to 2010. We collected fecal samples or digestive tracts from 13 Fishers opportunistically on the Olympic Peninsula from 2009 through 2013. Subsequently, we identified the species composition of each sample's contents to determine the primary foods consumed by the reintroduced Fishers. Fisher diets were diverse and dominated by mammalian prey. Contents of feces and digestive tracts of Fishers were composed primarily of Snowshoe Hare (Lepus americanus) remains, followed by lesser proportions of Mountain Beavers (Aplodontia rufa), Northern Flying Squirrels (Glaucomys sabrinus), Douglas Squirrels (Tamiasciurus douglasii), Southern Red-backed Voles (Myodes gapperi), shrews (Sorex spp.), and unidentified ungulate species. The diet of Fishers comprised species that occur across a wide range of land uses and management prescriptions, including previously logged forests and mature forests that have been set aside for retention of old-growth forest characteristics. Additional study of prey abundance and Fisher foraging behaviors related to structural habitat characteristics across a gradient of land uses would provide useful insights for enhancing the effectiveness of conservation efforts to benefit Fishers in Pacific Northwest coastal forests.

Geographical Distribution and Genetic Diversity of Bank Vole Hepaciviruses in Europe.

The development of new diagnostic methods resulted in the discovery of novel hepaciviruses in wild populations of the bank vole (Myodes glareolus, syn. Clethrionomys glareolus). The naturally infected voles demonstrate signs of hepatitis similar to those induced by hepatitis C virus (HCV) in humans. The aim of the present research was to investigate the geographical distribution of bank vole-associated hepaciviruses (BvHVs) and their genetic diversity in Europe. Real-time reverse transcription polymerase chain reaction (RT-qPCR) screening revealed BvHV RNA in 442 out of 1838 (24.0%) bank voles from nine European countries and in one of seven northern red-backed voles (Myodes rutilus, syn. Clethrionomys rutilus). BvHV RNA was not found in any other small mammal species (n = 23) tested here. Phylogenetic and isolation-by-distance analyses confirmed the occurrence of both BvHV species (Hepacivirus F and Hepacivirus J) and their sympatric occurrence at several trapping sites in two countries. The broad geographical distribution of BvHVs across Europe was associated with their presence in bank voles of different evolutionary lineages. The extensive geographical distribution and high levels of genetic diversity of BvHVs, as well as the high population fluctuations of bank voles and occasional commensalism in some parts of Europe warrant future studies on the zoonotic potential of BvHVs.

Responses of mustelids and small mammal prey to combined retention on clearcuts: Woody debris, green trees, and riparian structures

Small mustelids such as the American marten (Martes americana) and short-tailed weasel (Mustela erminea) are important furbearers in temperate and boreal forests and are negatively affected by clearcutting. A major prey species, the southern red-backed vole (Myodes gapperi), also disappears from clearcuts and does not return to abundance levels of uncut forest for many decades. We tested the hypotheses (H) that on newly clearcut sites, (H1) the presence of small mustelids, (H2) abundance, species richness, and species diversity of the forest-floor small mammal community, and (H3) reproduction of the major species: M. gapperi and the deer mouse (Peromyscus maniculatus), would be greater on sites with combined retention treatments of woody debris piles, riparian, and green-tree retention than on sites with no retention. A fourth hypothesis (H4) predicted that the above response variables on sites with combined structural retention would be comparable to or higher than those in uncut old-growth forest. Mustelid presence and populations of forest-floor small mammals were sampled on five replicated (n = 4) treatment sites from 2017 to 2020 in south-central British Columbia, Canada.Mean presence (index of activity patterns) of mustelids was statistically similar among sites but in the combined treatments was 1.4 to 2.9 times higher than that in the dispersed (no retention) and uncut forest sites and was likely biologically important. Mustelid presence was particularly evident in the debris piles and riparian sites. Mean abundance of M. gapperi was 11.1 to 16.6 times higher in the combined retention and uncut forest sites than the dispersed sites. Mean abundance of P. maniculatus was higher in the dispersed than uncut forest, but similar in the combined retention to these treatments. Mean total abundance, species richness, and species diversity of eight small mammal species were all higher (1.3 to 1.6 times) in the combined retention sites than the dispersed and uncut forest sites. Although not formally significant (P = 0.08), results for mustelid presence tended to support H1 that these small carnivores would occur more frequently on sites with combined structural treatments than the dispersed and uncut forest sites. The overall high total numbers (and species richness and diversity) of small mammal prey species supported H2 that abundance would be greater on sites with the combined retention than on the dispersed sites with no retention. Reproduction and survival followed the pattern of abundance for the major species, and hence H3 was supported. Higher mean total abundance in combined retention sites than in uncut forest supported H4 in 2017–2018 but not in 2019–2020 when an influx of generalist species increased total abundance in the dispersed sites. This study is the first to measure the responses of small mustelids and small mammal prey species to combined structural retention. One or more of these retention treatments is highly recommended during most harvesting regimes in these forests.

Население мелких наземных позвоночных животных памятника природы «Чеускинский бор» (Ханты-Мансийский автономный округ - Югра)

There are 25 specially protected natural areas of various status have been organized on the territory of the Khanty-Mansiysk Autonomous Okrug Ugra. Despite their great nature conservation value, the degree of study of flora and fauna, as well as the ecology of plants and animals in the territory of most of them, remains relatively low. Until now, special studies of small terrestrial vertebrates inhabiting the Cheuskinsky Bor have been carried out. In 2020, our research of small terrestrial vertebrates were carried out. The purpose of the study is to identify the species composition and some features of ecology (abundance, biotopic distribution) of small mammals, amphibians and reptiles. The research was carried out in July-September 2020. Metal cones were used to catch most of the vertebrate species. A total of 7400 cone-days have been worked out. 10 species of small mammals and 3 of amphibians are registered. The species composition of small mammals at the Cheuskinsky Bor site is relatively poor, 10 species were captured by cones, 3 were marked visually. The group of dominants included the common shrew and the red-backed vole. They accounted for 22% and 77%, respectively, of all recorded animals. Reptiles in the 2020 season were not registered in the counts, however, according to the literature, the habitat of the common European adder and viviparous lizard is known. Among amphibians, the moor frog and Siberian salamander are rare, the European toad is common. In the future, when conducting annual studies, the list of small mammals can be supplemented by 714 species of insectivores, bats and rodents, the list of amphibians 1 species.

Fate of Postharvest Woody Debris, Mammal Habitat, and Alternative Management of Forest Residues on Clearcuts: A Synthesis

Coarse woody debris on the forest floor contributes to maintenance of forest biodiversity and long-term ecosystem productivity. Down wood is often dispersed over harvested sites during logging activities, thereby leaving piles of postharvest debris as “excess” material at landings and roadsides. These wood residues may be burned in most jurisdictions in North America to reduce a perceived fire hazard. The fire hazard debate needs to acknowledge the documented benefits of woody debris retention while striking a balance among biodiversity, bioenergy, and alternative uses for debris, while reducing ignitions by humans. The burning of excess woody debris also creates smoke, causes the release of greenhouse gas (GHG) emissions, and creates human health issues, particularly for vulnerable individuals. The relationship of wildfire smoke to human health problems is well documented. However, there is no scientific evidence showing that postharvest debris piles are ignition points for forest fires, other than those caused by humans. Wood residues from forest harvesting or natural disturbance wood from wildfire and insect outbreaks may be used as renewable biomass “feedstocks” that could help improve energy supplies and reduce GHG emissions. If not marketable, the management of postharvest debris should seek alternative outlets that do not dispose of debris by burning, but still meet fire hazard abatement requirements. The construction of woody debris structures (e.g., piles and windrows) built at the time of forest harvesting and log processing, or later at the site preparation stages, has positive benefits for wildlife habitat and forest biodiversity. A windrow or series of piles may connect patches and reserves of mature forest and riparian areas on clearcut openings. Piles and windrows have consistently provided habitat on new clearcuts for southern red-backed voles (Myodes gapperi) and Microtus voles, as well as a host of other forest-floor small mammal species, at least up to 12 years postconstruction. Woody debris provides important habitat for foraging and cover attributes for marten (Martes americana), weasels (Mustela spp.), and other furbearers. A list of “What to do?” and “When and Where?” with options for construction of woody debris habitats: poorest, good, better, and best are given. In the cases where fire risk from humans is minimized and there are no marketable wood products, eight alternative management scenarios for postharvest woody debris are provided. These include: (1) piles for wildlife habitat; (2) distribution of debris in partial cut forests; (3) machinery to break up and crush debris; (4) protection of riparian zones with barriers for cattle; (5) construction of range fencing; (6) reclamation of landings and skid-trails; (7) soil fertility and reduction in weed competition and drought for planted conifers; and (8) slope stabilization and revegetation. Advantages and disadvantages (if known) are given for each alternative. A flow chart for the fate of excess postharvest woody debris with respect to fire hazard abatement and markets or nonmarkets is given.

Short-term effects of tree thinning on microhabitat variables and rodents in Japanese larch Larix kaempferi forest

We examined the short-term effects of tree thinning on microhabitat factors and the abundances of striped field mice Apodemus agrarius, Korean field mice Apodemus peninsulae, and Korean red-backed voles Myodes regulus within a Japanese larch Larix kaempferi forest in South Korea. Three different stands were thinned to 0%, 25%, or 50%. Ground vegetation was higher in the second year of tree thinning than in the first year. In the first year of thinning, ground vegetation was significantly higher in the control than in the 50% thinned stand, whereas the opposite trend was observed in the second year. Mid-story vegetation was higher in the control than in the 50% thinned stand. In the first year of thinning, the sub-overstory vegetation was higher in the control than in the 50% thinned stand. Basal area was the highest in the control stand. Abundances of the three rodent species were higher in the second year of tree thinning than in the first year. The abundance of A. peninsulae was higher in the control than in the 50% thinned stand. Overall, the three rodent species preferred microhabitats with dense ground vegetation. Our results showed that the short-term effects of tree thinning altered microhabitat factors and disturbed microhabitat conditions in the first year; furthermore, the 50% thinned stand did not provide suitable habitats for A. peninsulae. In this study, moderate (25%) tree thinning resulted in a convenient balance between biodiversity conservation and human demands for forest wood.

Geographic Ecological Analysis of Small Mammals of the Northern Taiga of Western Siberia

The analysis of all data on the number and distribution of small mammals in Western Siberia over the past 120 years has established that 20 out of 28 species recorded in the northern taiga make up their communities. A similar structure of dominance is generally preserved in the small mammal communities of the northern taiga. The main dominant species, northern red-backed vole, Laxmann’s shrew, and the common shrew, predominate almost everywhere. The other six codominant species (Eurasian pygmy shrew and tundra shrew and voles: root vole, common European field vole, European bank vole, and gray red-backed vole) dominate only in certain areas. The remaining 11 species, which are both widely and narrowly distributed, make up a small part of the communities. The increase in the species richness of communities to the east (from 15 to 19 species) is determined by the increase in the number of Siberian species. In general, in the studied area of the northern taiga, the largest contribution to small mammal communities is made by representatives of the Siberian fauna type, with the exception of the western part of the subzone, where European species predominate.

Late Quaternary Voles from Persistence Cave, Black Hills, South Dakota

Excavations at Persistence Cave (Black Hills, SD), produced a large sample of Quaternary microfauna including a diverse assemblage of arvicoline rodents. Identifiable lower first molars (n = 367) include specimens referred to heather vole (Phenacomys sp.), muskrat (Ondatra sp.), southern bog lemming (Synaptomys cooperi), red-backed vole (Myodes sp.), sagebrush vole (Lemmiscus curtatus), prairie vole (Microtus ochrogaster), and a form of meadow vole (Microtus sp.). Direct radiocarbon dating of specimens of Lemmiscus curtatus is consistent with previous records from the Nelson–Wittenberg Site and indicates that sagebrush voles inhabited the southern Black Hills roughly 40,000 yr BP. Direct ages for Myodes sp. and Microtus ochrogaster taxa are consistent with previously published data from Don's Gooseberry Pit, supporting previous interpretations of faunal turnover in the late Pleistocene/early Holocene. Collectively, the radiocarbon record suggests that deposition of fossils of arvicoline rodents at Persistence Cave occurred over a restricted period of time beginning approximately 40,000 yr BP. This period of deposition was followed by a depositional hiatus that included the Last Glacial Maximum, and deposition was reinitiated near the terminal Pleistocene.

Updated list of fleas (Insecta: Siphonaptera) of the Korean Peninsula, with the presence of Rhadinopsylla alphabetica Jameson amp; Sakaguti in the Democratic People's Republic of Korea.

During the re-examination of some specimens in the Siphonaptera collection of J.-C. Beaucournu, we noticed unidentified Rhadinopsylla specimens. After the detailed comparison, they were identified as Rhadinopsylla alphabetica Jameson Sakaguti. These specimens of R. alphabetica were collected from Grey Red-backed Vole, Myodes rufocanus (Sundevall), in Ryanggang province of the Democratic People's Republic of Korea (DPRK). To the best of our knowledge, this is the first report of R. alphabetica in the DPRK. Our specimens of R. alphabetica have some minor differences from Alaskan and Japanese populations. To draw attention to these differences we also provide detailed drawings of R. alphabetica specimens in the present study. The information on the flea fauna of the Korean peninsula is very fragmentary and articles on fleas of the Korean peninsula have been published in different languages. Therefore, it is very difficult to find accessible and updated flea list of the Korean peninsula for the scientific community. Based on the published and accessible literature, we provide a list of 45 flea taxa from the Korean peninsula.

ECTOPARASITES OF A STEPPE LEMMING LAGURUS LAGURUS PALLAS, 1773 IN THE SOUTH TRANS-URAL REGION (KURGAN OBLAST) IN CONNECTION WITH THE NATURAL FOCI OF TULAREMIA

Steppe lemming of the South Trans-Ural region is a rare species of open spaces. To the north, its distribution is limited to the subzone of herb-bunchgrass steppes and the southern strip of the forest-steppe subzone. The presented work summarizes the material, which gives the full species composition of the parasitic arthropods of this rodent, and gives quantitative characteristics of ectoparasites. In total 155 individuals and one nest of steppe lemming were examined for ectoparasites. There are 808 parasitic arthropods of 20 species, including 14 species of gamasid mites, 2 species of ixodid ticks and 4 species (subspecies) of fleas. According to the number of individuals of ectoparasites feeding on the steppe lemming, the dominance of gamasid mites is strongly pronounced, both prevailing multi-host species and specific, typical for other rodents (gray and red-backed voles, northern mole vole, Eurasian water vole, northern birch mouse). The contribution of ixodid ticks and fleas to the parasitofauna of the steppe lemming is small. Steppe lemming can be involved in circulation of a causative agent of tularemia in the South Trans-Ural region, but as an additional carrier in maintenance of a foci in biotopes, where it contacts the habitats of the Eurasian water vole.

Functional responses in habitat use explain changes in animal–habitat interactions during forest succession

The growing rate of resource extraction forces increasing numbers of late-seral species to occupy habitats that are in early stages of succession. Sustainable management must maintain habitat features that are required for recovery of these species, which may be challenging because their response to those features can vary following nonsystematic trends during stages of succession. We investigated whether simple movement rules could explain such variations by assessing how movements of a late-seral species, the red-backed vole (Myodes gapperi (Vigors, 1830)), vary during postlogging forest succession using the spool and line technique in recent cuts, mid-successional forests, and old-growth forests. We found that voles moved selectively along coarse woody material (CWM), and this selection was weaker in mid-successional forests. This change was best explained by a simple functional response, whereby voles selected CWM more strongly in stands where canopy cover availability was moderately high. Likewise, voles more rapidly left patches that had high canopy cover when it was less available in stands and tended to spend more time in patches with high CWM volumes. Our study demonstrates that the highly dynamic nature of animal–habitat relationships observed during forest succession can be summarized by a few simple functional responses in movement and habitat selection.