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Species richness relative abundances and habitat use in local assemblages of Sorex shrews in Eurasian boreal forests

100%

Sheftel B. I., Hanski I.

Acta Theriologica. Supplement

2002

tom 47

nr 1

Using a large body of observational data on the occurrence of Sorex 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.

Amplification of DNA markers from scat samples of the least weasel Mustela nivalis nivalis

80%

Wang R., Painter J. N., Hanski I.

Acta Theriologica

2002

tom 47

nr 4

To test the feasibility of using field-collected scats as a source of DNA in the study of the least weasel Mustela nivalis nivalis Linnaeus, 1766, DNA was extracted from scat samples collected from captive weasels using a modified extraction protocol. Using universal primers, the control region of the mitochondrial genome was successfully amplified from scat-extracted DNA. This amplification resulted in two products; one equivalent in size and sequence to the product obtained from tissue-extracted weasel DNA, and the other slightly larger and equivalent in size and sequence to the domestic house mouse Mus musculus, the food source of the captive weasels. This demonstrates the reliability of DNA extraction from scats, as well as the possibility, under favourable circumstances, of identifying the prey species from the same samples. In addition, we attempted to amplify microsatellite loci from both tissue and scat-extracted DNA using six primer pairs designed for other mustelids, the American mink Mustela vison and the wolverine Gulo gulo. While three loci, Mvi57 (American mink), Ggu216 and Ggu234 (wolverine), were found to be polymorphic in the least weasel, amplification of these loci from the scat extracted DNA was only successful for approximately half of the samples. Although further work is needed, the present results suggest that it is possible to use scats as a source of DNA in field studies of the least weasel.

Ograniczanie wyników

1 Acta Theriologica

1 Acta Theriologica. Supplement

2 Hanski I.

1 Painter J. N.

1 Sheftel B. I.

1 Wang R.

2 2002

Wyniki wyszukiwania

Species richness relative abundances and habitat use in local assemblages of Sorex shrews in Eurasian boreal forests

Amplification of DNA markers from scat samples of the least weasel Mustela nivalis nivalis