Dispersal of Young Common Shrews (Sorex araneus) from Natal Ranges

Abstract

Natal dispersal of young common shrews (Sorex araneus) was studied in field conditions in the southern part of Tver oblast, in central European Russia. Total individual marking of shrews was conducted over an area of 22 ha. The places of birth of the young were determined by the home ranges of relative overwintered females. The animals were genotyped by ten microsatellite loci: L62, L68, L45, C117, L69, C5, B30, D106, D103, and D138. Family analysis was carried out using the Cervus 3.07 software. In 2013, with the population density in October being 6.5 individuals/ha, 33 mother‒pup dyads were identified for 229 yearlings and 20 females. The share of yearlings born within the study area was 14.8%, while the core of the population consisted of animals that had arrived from outside the plot. In 2014, with the population density in October reaching only 2.6 individuals/ha, nine mother‒pup dyads were found for 58 yearlings and nine mature females. The share of the animals born within the plot boundaries was 15.5%. Within the plot, dispersal from the natal ranges varied from 0 to 610 m, Me = 224, in 2013, and from 45 to 410 m, Me = 297, in 2014. The data obtained fail to confirm a meaningful year-to-year difference. Taking into account the corrections for the proportion of territory under control, the majority of young animals appear to have dispersed over a range of more than 400 m both during the high fall population density and during its decrease the next year.