Linas Balčiauskas

New Data on the Helminth Fauna of Rodents of Lithuania

Six house mice (Mus musculus), seven yellow-necked mice (Apodemus flavicollis), 10 striped field mice (A. agrarius), five muskrats (Ondatra zibethicus), one water vole (Arvicola terrestris), 126 bank voles (Clethrionomys glareolus), 12 short-tailed voles (Microtus agrestis), and two European beavers (Castor fiber) were examined for helminths. Data are presented about infection of the rodents with trematodes, nematodes, and larvae of cestodes. Twenty three helminth species were found. In Lithuania, Echinococcus multilocularis was found in rodents for the first time. Three helminths were found in new hosts in Lithuania: Plagiorchis elegans – in the bank vole, Mastophorus muris – in the house mouse, and Tetratirotaenia polyacantha – in the muskrat. In the European beaver, only Stichorchis subtriquetrus and Travassosius rufus, helminths specific to this species, were detected. The helminth fauna in the muskrat and the water vole was formed of helminths hosted by a wide range of waterfowl and mammals.

EUROPEAN BISON (BISON BONASUS) IN LITHUANIA: STATUS AND POSSIBILITIES OF RANGE EXTENSION

Since 1973, Lithuania has been one of few European countries with a vital free-ranging bison herd. The article analyses a current state of the bison population and problems of the last decade. Data are presented on the dynamics of numbers of fenced and free-ranging bison, bison biology features (nutrition, damage done, reproduction, changes in behaviour), territory occupied by the herd and migrations. Having analysed the reasons of failed setting free of the bison herd in Sirvintos Region, details of the project of a new bison herd in South Lithuania are provided (aims, place selection criteria, technical preconditions of successful realisation). The suitability of the Bukta forest for the range extension of the bison population is discussed along with possible problems.

DIVERSITY OF SMALL MAMMAL COMMUNITIES IN LITHUANIA (1. A REVIEW)

Abstract Summary of small mammal trapping data in Lithuania is given in the first article of a series. Results are reviewed from the point of view of trapping effort, character of investigation and the interdependencies of community indexes. Consideration about the threshold of trapping effort is presented along with practical implications on the correct use of community indexes.

Results of the Long-Term Monitoring of Small Mammal Communities in the Ignalina Nuclear Power Plant Region (Drūkšiai LTER Site)

The paper presents data on the number of small mammal (SM) species, diversity indices of their communities, and bank vole (Clethrionomys glareolus) reproduction disturbances in 1981–1990 in the Ignalina Nuclear Power Plant Region (Drūksiai LTER site). The most polydominantic SM communities were registered in meadows; the most monodominantic in forests and bogs of the region. The average SM abundance in the region was 11.77 ± 0.58 (in autumn, 21.26 ± 1.20) individuals per 100 trap-nights. The bank vole was the dominating species (68% of all trapped individuals). In 1986–1988, the diversity of SM communities significantly decreased, while dominance increased. After the year 1984, significant bank vole breeding disturbances were observed in the form of non-implantation and embryo resorption. Such disturbances involved 68.4% of all breeding bank vole females in 1984, 45.1% in 1985, 36.7% in 1986, 46.5% in 1987, 56.7% in 1988, 27.9% in 1989, and 22.7% in 1990.

The genetic structure of the Lithuanian wolf population

Lithuanian wolves form part of the larger Baltic population, the distribution of which is continuous across the region. In this paper, we evaluate the genetic diversity of the Lithuanian wolf population using mitochondrial DNA analysis and 29 autosomal microsatellite loci. Analysis of the mtDNA control region (647 bp) revealed 5 haplotypes distributed among 29 individuals and high haplotype diversity (0.658). Two haplotypes were distributed across the country, whilst the others were restricted to eastern Lithuania. Analysis of microsatellites revealed high heterozygosity (HE=0.709) and no evidence for a recent bottleneck. Using detection of first generation migrants, four individuals appeared to assign better with populations genetically differentiated from those resident in Lithuania. These immigrants were males carrying rare mitochondrial haplotypes and were encountered in the eastern part of the country, this indicates that Lithuania is subject to immigration from differentiated populations. Additionally, we did not detect any signs of recent hybridisation with dogs.

Root vole, Microtus oeconomus, in Lithuania: changes in the distribution range.

Abstract. Lithuania is on the edge of the main distribution range of the root vole (Microtus oeconomus). It was found that the trappability of M. oeconomus did not depend on the trapping effort, the number of recorded species and individuals or the species diversity. All 13 localities with proportions of M. oeconomus constituting over 30% of the small mammal community are situated in the south and west of Lithuania. Analysis of data collected over 50 years confirms that the species has become more abundant, more widespread and its distribution range has spread north and east from the south and west of the country. The main habitats for M. oeconomus in Lithuania are reedbeds, meadows, shrubby areas and shores of water bodies. Abandoned former agricultural areas create suitable habitats for the species, thus promoting its increased abundance and wider distribution.

THE BIODIVERSITY DATABASE IN LITHUANIA—DISTRIBUTIONAL AND ENVIRONMENTAL APPLICATIONS

Abstract The DBMS software, currently being used for the Biodiversity database management, developed by the project group “Ecological diversity of Lithuania” and currently maintained at the Institute of Ecology (Vilnius, Lithuania), is Borland® Paradox®, mainly Paradox® for DOS ver. 4.5. The relational structure of the database contains minimum of coding and allows to perform data management and all basic outputs, using forms and reports of the standard interface, it does not require special programs or applications in DBMS environment. The database contains a taxonomic and literature citation blocks, species distribution data files (Budrys, 1998, in press). Particular data block of the database contains lists of geographic names, and habitat information. These files are linked to a master file with records related to 1×1 km grid of territory, designed as a raster database. For particular purposes of inexperienced user, a minimized regional version of the database (RBIDB) with a user-friendly interface wa...

Homogenous Population Genetic Structure of the Non-Native Raccoon Dog (Nyctereutes procyonoides) in Europe as a Result of Rapid Population Expansion

The extent of gene flow during the range expansion of non-native species influences the amount of genetic diversity retained in expanding populations. Here, we analyse the population genetic structure of the raccoon dog (Nyctereutes procyonoides) in north-eastern and central Europe. This invasive species is of management concern because it is highly susceptible to fox rabies and an important secondary host of the virus. We hypothesized that the large number of introduced animals and the species’ dispersal capabilities led to high population connectivity and maintenance of genetic diversity throughout the invaded range. We genotyped 332 tissue samples from seven European countries using 16 microsatellite loci. Different algorithms identified three genetic clusters corresponding to Finland, Denmark and a large ‘central’ population that reached from introduction areas in western Russia to northern Germany. Cluster assignments provided evidence of long-distance dispersal. The results of an Approximate Bayesian Computation analysis supported a scenario of equal effective population sizes among different pre-defined populations in the large central cluster. Our results are in line with strong gene flow and secondary admixture between neighbouring demes leading to reduced genetic structuring, probably a result of its fairly rapid population expansion after introduction. The results presented here are remarkable in the sense that we identified a homogenous genetic cluster inhabiting an area stretching over more than 1500km. They are also relevant for disease management, as in the event of a significant rabies outbreak, there is a great risk of a rapid virus spread among raccoon dog populations.

Diversity of Small Mammals in Winter Season in North East Lithuania

The trapping of small mammals was done in two winter seasons (2004/2005 and 2005/2006) in the Zarasai district, north-east Lithuania. Nine small mammal species were registered. For Apodemus uralensis, it was the first finding of the species in north-east Lithuania. C. glareolus (49.4% of all trapped animals) were dominating in both seasons both by numbers and by frequency of occurrence. The shares of M. oeconomus, A. uralensis, A. agrarius and M. musculus were less than 1% each. One to six small mammal species were registered every month. Towards spring numbers of trapped C. glareolus decreased; in March–April dominant became M. arvalis. The dominance of C. glareolus was lessening towards spring, when it was changed by M. arvalis. The diversity of the small mammal community in the winter period was not high (averaged Shannons H = 1.27). Negative correlation (r = -0.64) was found between the number of trapped animals per session (100 traps) and snow depth. M. arvalis was registered breeding quite early: f...

Preliminary Assessment of Damage Caused by the Wolf in Lithuania

According to the data of a questionnaire research carried out in 1999–2001, a preliminary assessment of damage caused by wolves in Lithuania is given. The most serious damage was recorded in Biržai, Kelmė, Joniskis, and Siauliai districts. Depredation cases were most common in summer and autumn. Cattle, sheep, and dogs were attacked not only in pastures, but also in farmsteads and even villages, even if dogs were kept in yards. One fourth of the attacks was recorded further than 1 km from forests. As a rule, animals were not guarded in the day time and were left in pastures for the night. Usually they were uninsured, so losses were not compensated. According to livestock owners who had suffered losses, the damage should be compensated by the Ministry of Environment or the Ministry of Agriculture and hunters. According to a preliminary assessment, at present wolves annually kill about 400–1,200 animals in Lithuania; this is fewer than in the 1920s or mid-1950s, but more than in neighbouring Latvia. Owners ...