Alius Ulevičius

Mitochondrial phylogeography of the Eurasian beaver Castor fiber L.

Nucleotide variation in an approximately 490 bp fragment of the mitochondrial DNA control region (mtDNA CR) was used to describe the genetic variation and phylogeographical pattern in the Eurasian beaver (Castor fiber) over its entire range. The sampling effort was focused on the relict populations that survived a drastic population bottleneck, caused by overhunting, at the end of the 19th century. A total of 152 individuals grouped into eight populations representing all currently recognized subspecies were studied. Sixteen haplotypes were detected, none of them shared among populations. Intrapopulation sequence variation was very low, most likely a result of the severe bottleneck. Extreme genetic structure could result from human‐mediated extinction of intermediate populations, but it could also be an effect of prior substantial structuring of the beaver populations with watersheds of major Eurasian rivers acting as barriers to gene flow. Phylogenetic analysis revealed the presence of two mtDNA lineages: eastern (Poland, Lithuania, Russia and Mongolia) and western (Germany, Norway and France), the former comprising more divergent haplotypes. The low level of sequence divergence of the entire cytochrome b gene among six individuals representing six subspecies suggests differentiation during the last glacial period and existence of multiple glacial refugia. At least two evolutionary significant units (ESU) can be identified, the western and the eastern haplogroup. The individual relict populations should be regarded as management units, the eastern subspecies possibly also as ESUs. Guidelines for future translocations and reintroductions are proposed.

GENETIC VARIATION AND POPULATION STRUCTURE OF THE EURASIAN BEAVER CASTOR FIBER IN EASTERN EUROPE AND ASIA

Abstract The Eurasian beaver, Castor fiber L., suffered extreme demographic reduction through overhunting until the end of the 19th century. However, active protection measures have led to a powerful recovery in range and population numbers. The vast majority of beavers (83%) now occur in the former Soviet Union. The present study investigates the geographic distribution of genetic variation of C. fiber in this eastern part of the species range (former Soviet Union and Mongolia), with special emphasis on small isolated populations of the Asian subspecies C. fiber pohlei, C. fiber tuvinicus, and C. fiber birulai. The analysis yielded 12 different haplotypes, all of which were population specific. Results indicate that C. fiber displays great population structuration (FST = 0.985), coupled with an overall low level of genetic divergence (mean number of pairwise differences 7.262 ± 3.435). In particular, the autochthonous populations in Mongolia or Siberia do not appear significantly different from samples from the European part of Russia, despite the great geographical distance. C. f. birulai appears as the most divergent member, a fact that could result from its longer genetic isolation in an enclosed watershed. Examination of our data suggests a single recent origin of the present beaver population in eastern Europe and Asia.

Nuclear and mitochondrial genetic structure in the Eurasian beaver (Castor fiber) – implications for future reintroductions

Many reintroduction projects for conservation fail, and there are a large number of factors that may contribute to failure. Genetic analysis can be used to help stack the odds of a reintroduction in favour of success, by conducting assessment of source populations to evaluate the possibility of inbreeding and outbreeding depression and by conducting postrelease monitoring. In this study, we use a panel of 306 SNP (single nucleotide polymorphism) markers and 487–489 base pairs of mitochondrial DNA control region sequence data to examine 321 individuals from possible source populations of the Eurasian beaver for a reintroduction to Scotland. We use this information to reassess the phylogenetic history of the Eurasian beavers, to examine the genetic legacy of past reintroductions on the Eurasian landmass and to assess the future power of the genetic markers to conduct ongoing monitoring via parentage analysis and individual identification. We demonstrate the capacity of medium density genetic data (hundreds of SNPs) to provide information suitable for applied conservation and discuss the difficulty of balancing the need for high genetic diversity against phylogenetic best fit when choosing source population(s) for reintroduction.

New Data on the Pygmy Field Mouse (Apodemus Uralensis) Distribution and Habitats in Lithuania

Pygmy field mouse (Apodemus uralensis) was identified as a new mammal species in Lithuania only in 1999. Despite that, many new localities of this species were discovered in northwestern and western Lithuania during 1999–2000: in Žemaitija National Park, Kurtuvėnai and Varniai regional parks, Kamanos strict nature reserve and almost on all the territory of Mažeikiai administrative district. A total of 62 individuals of A. uralensis were captured in 33 localities in 1996–2000. The collected data on A. uralensis dwelling places prove that it is an ‘ecotonic’ species most often residing on the edges of forests and in open habitats bordering on forests. The greatest number of these mice were captured in the ecotones of forests and open habitats (meadows, cornfields and fallow fields) and in open habitats bordering on forests or situated close to them (natural meadows overgrown with shrubs, grass-covered reclamation canals, cornfields). Rather few mice of this species were captured in forests, most often close...

BURROWING CARNIVORES IN ŽEMAITIJA NATIONAL PARK, NW LITHUANIA: BURROW SETTS AND TERRITORY USE

Abstract Making use of the questionnaires of hunters, in 1997 69 burrow setts were registered in the 20000 ha area of Žemaitija National Park, NW Lithuania. The burrow use in 27 burrow setts was investigated in the second decade of Jun. 1997. The territory use of burrowing mammals—Red Fox, Racoon Dog, and Badger—was estimated as relative abundance, i.e. average number of signs (mainly tracks) per 1 km route—of “black path” (May 1997; 45 km) and “white path” (February—March 1998; 50 km). The density of burrow setts in separate forest tracts ranged from 9.2 to 11.7 burrow setts/1000 ha (10.5 on the average). Small—up to 5 entrances—burrow setts made 46 %; setts not exceeding 10 entrances, 37 %; and setts of more than 10 entrances, 17 %. From the 27 burrow setts investigated, in 8 (30 %) juvenile litters were detected: 2 fox, 3 racoon dog and 3 badger litters. 10 burrow setts (37 %) were constantly visited by badgers or racoon dogs, 9 burrow setts (33 %) were occasionally used by foxes or were neglected; 25 ...

Spatial Relations among Semi-Aquatic Mammals on the Riverside

A total of 231 riverside cut-offs (0.5 km in length and approx. 10 m in width from the water edge) were investigated on the subject of the joint use by semi-aquatic mammals – the beaver (Castor fiber), otter (Lutra lutra), American mink (Mustela vison), and muskrat (Ondatra zibethicus) – in 10 rivers of south and southeast Lithuania. Relative abundance was expressed as the number of activity signs per a 0.5-km cut-off. The co-occurrence of two or more species on a single 0.5-km-long riverside cut-off and the correlation analysis of the relative abundance of semi-aquatic mammals were used to evaluate spatial relations in the community. High level of co-occurrence of semi-aquatic mammals was found. Of all the 0.5-km cut-offs investigated, 97.9% were used by two or more species. However, significant correlation in the relative abundance between two species of semi-aquatic mammals was found only in 6 of the 60 combinations possible. The average relative abundance of semi-aquatic mammals (except for the beaver...

Changes in the Territory Use by Semi-Aquatic Mammals in Some of Rivers in Lithuania

Changes in the intensity of the shoreline use by semi-aquatic mammals – beaver, muskrat, otter, and American mink – in five rivers in Lithuania during the period of 8–9 years have been investigated. The intensity of the shoreline use was expressed in the number of tracks of activities of the mammals within 0.5-km-long shoreline cut-offs. Very different changes were established for both individual rivers and individual species. The intensity of the shoreline use by carnivores – otter and American mink – changed (decreased or increased in particular cut-offs) most of all. The intensity of the shoreline use by beaver increased in all cut-offs (not in all of them significantly). Muskrat was abundant in three rivers at the beginning of the investigation, but it became practically extinct in two of them 8–9 years after. In many cases, the intensity of the use of the same cut-offs at the beginning and at the end of the investigation did not correlate, i.e. changes were accidental. Changes in the intensity of the...

BIODIVERSITY EVALUATION AT THE LOCAL LEVEL: METHODOLOGICAL AND TERRITORIAL ASPECTS

Abstract Short summary of the results of investigations in Radviliskis, Telsiai and Salcininkai districts is given in this paper, covering territorial aspects, species composition and communities, measures needed for further protection.