Communities of ectoparasitic arthropods associated with the root vole Microtus oeconomus in north-eastern Poland

Ectoparasitic arthropods communities associated with root voles Microtus oeconomus (Pallas, 1776) were analysed in north-eastern Poland. The first M. oeconomus parasites recorded in the history were the fleas Palaeopsylla similis Dampf, Ctenophthalmus congerer Rothschild, C. bisoctodentatus Kolenati, and C. solutus Jordan et Rothschild. Ctenophthalmus uncinatus (Wagner) and Doratopsylla dasycnema (Rothschild) fleas and the Ixodes apronophorus Schulze tick were recorded on M. oeconomus in Poland for the first time. These species are relatively rare in Poland and specific to other species of small mammals. The incidence of M. oeconomus infestations with I. apronophorus, D. dasycnema and C. uncinatus ranged from 0.5 to 0.8 %, respectively. There are large differences in the infestation of Dermacentor reticulatus larvae and nymphs between July and August. In July, D. reticulatus may be considered the dominant ectoparasite species, in August, it is partly replaced by I. ricinus and fleas and is subdominant.

Issues of under-representation in quantitative DNA metabarcoding weaken the inference about diet of the tundra vole Microtus oeconomus

During the last decade, methods based on high-throughput sequencing such as DNA metabarcoding have opened up for a range of new questions in animal dietary studies. One of the major advantages of dietary metabarcoding resides in the potential to infer a quantitative relationship between sequence read proportions and biomass of ingested food. However, this relationship’s robustness is highly dependent on the system under study, calling for case-specific assessments. Herbivorous small rodents often play important roles in the ecosystem, and the use of DNA metabarcoding for analyses of rodent diets is increasing. However, there has been no direct validation of the quantitative reliability of DNA metabarcoding for small rodents. Therefore, we used an experimental approach to assess the relationship between input plant biomass and sequence reads proportions from DNA metabarcoding in the tundra vole Microtus oeconomus. We found a weakly positive relationship between the number of high-throughput DNA sequences and the expected biomass proportions of food plants. The weak relationship was possibly caused by a systematic under-amplification of one of the three plant taxa fed. Generally, our results add to the growing evidence that case-specific validation studies are required to reliably make use of sequence read abundance as a proxy of relative food proportions in the diet.

Paleoclima y Paisaje del final del Cuaternario en Cantabria: los pequeños mamíferos de la cueva del Mirón (Ramales de la Victoria)

La gran diversidad en pequeños mamíferos del Pleistoceno superior y Holoceno de la Cueva del Mirón, con un total de 26 especies pertenecientes a seis órdenes de mamíferos (Erinaceomorpha, Soricomorpha, Chiroptera, Carnivora, Rodentia y Lagomorpha) hace de la secuencia del Mirón un importante documento sobre la distribución de las asociaciones de pequeños mamíferos durante la transición Pleistoceno-Holoceno; lo que nos permite conocer la evolución del clima y del paisaje en la Región Cantábrica. Al final del Cuaternario se registra la última extinción de microfauna Pleistocena, como la del topillo Pliomys lenki, relacionado con el actual Dinaromys, el topillo nival de los Balcanes o de Martino. También se documentan extinciones locales, como la desaparición del territorio español de los mamíferos característicos de las estepas del Norte de Europa y Siberia, como Microtus oeconomus y M. gregalis. Estas extinciones se pueden explicar por los cambios climáticos ocurridos al final del Cuaternario, sin descartar la competencia con especies inmigrantes, de ecología similar. El final del Holoceno, la actividad humana, sobre todo la deforestación y la cultura cerealística, se refleja también en la disminución de la diversidad específica de los pequeños mamíferos.

Data on the distribution of Hystrichopsylla orientalis fleas (Siphonaptera) in Lithuania

The aim of this study was to present data on the distribution of Hystrichopsylla fleas collected from different animals in Lithuania. The study was done by analyzing collections of fleas from 2011 to 2017. A total of 96 fleas of the genus Hystrichopsylla were collected from nine mammalian species (Apodemus flavicollis, Apodemus agrarius, Micromys minutus, Myodes glareolus, Microtus oeconomus, Microtus arvalis, Sorex araneus, Neomys fodiens, and Glis glis). Morphological analysis showed that all fleas were of the species Hystrichopsylla orientalis Smit, 1956.

Effects of short-time cold impact on hematologic chrarcteristics of tundra vole (Microtus oeconomus PALLAS)

Проведено изучение воздействия низкой температуры (-50С) в течение двух часов на гематологические показатели самцов полевок-экономок (Microtus oeconomus Pallas) разного возраста (2, 4 и 10 месяцев). Обнаружена зависимость проявления эффекта от возраста животных. В большей степени на общее переохлаждение реагировали полевки старшей возрастной группы. Установлено, что действие холода вызывает умеренную лейкопению и лимфопению у половозрелых животных (4 и 10 месяцев), а также понижение содержания тромбоцитов в периферической крови у 10 месячных самцов. Полученные данные свидетельствуют о чувствительности показателей периферической крови самцов полевок-экономок к кратковременному действию низкой температуры и являются отражением неспецифичных клеточных реакций. We studied the effect of the 2-hours exposure to the low temperature (-50°C) on the hematological parameters of male tundra vole (Microtus oeconomus Pallas) of different ages (2, 4, and 10 months). We found the relation of the effect on the age of the animals. Voles of the older age group responded to a higher degree to general hypothermia. The action of the cold causes moderate leukopenia and lymphopenia in mature animals (4 and 10 months), as well as a decrease in platelet content in peripheral blood in 10-month-old males. The data obtained indicate the sensitivity of the peripheral blood indices of male tundra voles to the short-term effect of low temperature. They are a reflection of non-specific cellular reactions.

Mouse-like rodents and shrews in Kharkiv Oblast (Ukraine): species composition, distribution, and current state of populations

Since 1957, zoologists of the Kharkiv Sanitary and Epidemiological Station have been conducting annual monitoring of small mammals in Kharkiv Oblast. To assess the current state of populations of mouse-like rodents and shrews, we analysed a dataset for the period from 2000 to 2018. The small mammal fauna was studied at 117 sites in 27 districts (raions) of Kharkiv Oblast. Various types of oak forests, dry and floodplain meadows, riparian vegetation, steppe areas, forest stripes, gardens, fields, and haystacks were examined. Four species of insectivores and 16 species of mouse-like rodents were identified. The dominant and widespread species in the region are Sylvaemus uralensis, Apodemus agrarius, Sorex araneus, Microtus levis, Myodes glareolus, and Sylvaemus tauricus. Some species are less common and in some areas of the region have not yet been identified, including Sorex minutus, Sylvaemus sylvaticus, Crocidura suaveolens, Micromys minutus, Cricetulus migratorius, and Microtus oeconomus. The least common species with single records include Neomys fodiens, Mus spicilegus, Lagurus lagurus, Terricola subterraneus, Dryomys nitedula, and Arvicola amphibius. Indigenous species of the region include seven species, another seven species are those that increased their number and range, three species have recently appeared in the region due to dispersal from adjacent territories, while, on the contrary, the abundance and range of three species have declines. Microtus oeconomus is characterised by a current southward range expansion. Myodes glareolus, which was mentioned in the last century north of our region, is now widely distributed throughout the region and further south. Lagurus lagurus is an invasive species with periodic population outbreaks in the region and currently is rarely recorded.