Boris I. Sheftel

Species richness, relative abundances and habitat use in local assemblages ofSorex shrews in Eurasian boreal forests

Using a large body of observational data on the occurrence ofSorex shrews in boreal forests, we test two models that predict the structure of small mammal communities along a gradient of increasing habitat productivity. Tilman’s (1982) model predicts a humped curve of species richness along productivity gradients. In contrast, we found a linear increase in species richness with increasing logarithm of the pooled density of shrews, which we use as a measure of habitat productivity for shrews. The model of Hanski and Kaikusalo (1989) assumes a trade-off between exploitative and interference competitive abilities, and it predicts that the size structure of small mammal communities should shift from the dominance of small species (superior in exploitative competition) in unproductive habitats to the dominance of large species (superior in interference competition) in productive habitats. Shrew assemblages show such a shift. Though it is not possible to draw definite conclusions about the role of interspecific competition from our observational data, the changing size structure of local shrew assemblages with increasing habitat productivity is a predictable feature of their community structure.

Phylogenetic position of the gansu mole Scapanulus oweni thomas, 1912 and the relationships between strictly fossorial tribes of the family talpidae

The results of the first molecular study focused on the phylogenetic position of the Gansu mole, Scapanulus oweni are presented. The analysis based on sequences of the mitochondrial cytb gene and five nuclear genes supports the monophyly of the Scalopini tribe including S. oweni and shows that two highly fossorial talpid tribes, Talpini and Scalopini, are not immediate sister taxa. These results highlight the role of morphological parallelism as a potential source of conflict between molecular and morphology-based phylogenies in Talpidae.

Intraspecific Phylogeny and Nucleotide Diversity of the Least Shrews, the Sorex minutissimus-S. yukonicus Complex, Based on Nucleotide Sequences of the Mitochondrial Cytochrome b Gene and the Control Region

Abstract. Phylogenetic analysis was conducted for various populations of the Sorex minutissimus-S. yukonicus complex based on mitochondrial gene (cytochrome b and/or the control region) sequences. Sorex minutissimus was divided into some monophyletic groups in Eurasia; it was divided into 2 main groups, eastern and western Eurasian clades, based on combined data of the cytochrome b and the control region. Monophyly of shrews from Hokkaido-Sakhalin, Primorye, Mongolia-Transbaikalia, southeastern Finland was strongly supported respectively in most analyses. Sorex yukonicus was phylogenetically close to S. minutissimus in eastern Siberia. Some shrews from western and central Siberia were included in the clade of southeastern Finland. Also, most shrews from central-northern Finland and Norway made a clade close to but different from the southeastern Finland clade. This finding suggests that Fennoscandian shrews might consist of individuals which were recolonised from various refugia after the Last Glacial Maximum. Nucleotide diversity of shrews from Hokkaido and Alaska was low. Three regional groups in Kamchatka-Sakha, Sakhalin, and Mongolia-Transbaikalia tended to have medium nucleotide diversity. In contrast, shrews from Cisbaikalia-western Siberia and Fennoscandia had high nucleotide diversity. The S. minutissimus-S. hosonoi group appears to have experienceed a quit different biogeographic history from two shrews with similar ranges, the S. caecutiens-S. hosonoi group and S. tundrensis.

Western Siberia rivers and the boundaries between chromosomal races of the common shrew (Sorex araneus L. Lipotyphla, Mammalia)

In Western Siberia, most boundaries between common shrew chromosomal races have been found to pass along the banks of rivers, mainly those flowing in the meridional direction. The races Serov and Novosibirsk co-inhabited the right bank of the Irtysh. The easternmost point of the Novosibirsk race has been found on the middle Yenisei River, while the race Tomsk in this area was only on the right (eastern) bank.

Evolutionary history of the genus Sorex (Soricidae, Eulipotyphla) as inferred from multigene data

The genus Sorex is one of the most diverse and ecologically successful lineages of the family Soricidae. We present the first multilocus nuclear phylogeny focusing on the nominal subgenus Sorex s.str., which is distributed mainly in the northern Palearctic. The nuclear tree (six exons) provides more resolution than the mitochondrial data (cytb) and supports subdivision into eight species groups within Sorex s.str., most of which correspond to those recognized from chromosome data. The European species S. alpinus is consistently placed as the basal lineage in the Palearctic clade, while the next split separates the east‐Tibetan group of striped shrews (S. aff. cylindricauda, S. bedfordiae, S. excelsus). Within the remaining species, the following well‐supported clades are identified at the supra‐group level: “araneus” species group+S. samniticus; the “caecutiens” group+the “minutus” group, the latter also including S. minutissimus, S. gracillimus and S. thibetanus. S. raddei and S. roboratus represent separate lineages with no close relatives. The fossil‐calibrated molecular clock placed the divergence between Sorex s.str. and Otisorex at the Early/Middle Miocene boundary. Basal radiation of the crown Sorex s.str. was estimated to have occurred in the middle of the Late Miocene. A more than threefold increase in the diversification rate is inferred for the Early Pliocene. Taxonomic implications including potential genus ranks for Sorex s.str. and Otisorex are discussed. S. alpinus is placed in the monotypic subgenus Homalurus. The full species status of S. buchariensis and S. thibetanus and close relationships between S. cf. cansulus and S. caecutiens are confirmed.

Is the Center of Origin of Long-tailed Hamster Cricetulus longicaudatus Milne-Edwards 1867 (Rodentia, Cricetidae) Located in Tibet?

First data on morphological and mitochondrial variation in the long-tailed hamster Cricetulus longicaudatus is presented. In contrast to genetically monomorphic populations of Mongolia and Tuva, the northeastern part of the Qinghai–Tibetian Plateau was found to harbor several divergent mtDNA lineages. This pattern suggests a recent expansion of the long-tailed hamster to the northern part of its recent range, which started from Tibet, presumably, in the late Middle Pleistocene. Several populations from the northern edge of the species range were found to be morphologically but not genetically distinct. The apparent disagreement between genetic and morphological data can be explained by rapid morphological evolution in peripheral isolates.

Unexpectedly High Genetic Diversity of the Asiatic Short-Tailed Shrews Blarinella (Mammalia, Lipotyphla, Soricidae)

Genetic diversity of the genus Blarinella was studied using one mitochondrial and four nuclear genes as examples. The first genotyping of shrews from the southeast of Gansu province (China), which is a typical habitat of B. griselda, has been performed. Molecular genetic analysis showed that Blarinella sp. from southern Gansu stand apart among the other representatives of the genus and can be assigned to neither of the known species.