Тhe mediterranean water shrew (neomys anomalus) in northern belarus: new records and identification criteria

Abstract

The article analyses the new record of Neomys anomalus in the lakes Dolzhin (geographic coordinates of the place of capture 55°06´33,8˝N, 28°36´03.1˝E) and Vechelye (55°07´55.3˝N, 28°36´38.6˝E and 55°07´55.4˝N, 28°36´37.2˝E) of Ushachsky district, Vitebsk region, Belarus. The material was collected in July 2019. Captured individuals (n = 3) differed by individual external characteristics (a grey-white spot around the eye but not behind it; non-contrasting transition of colouration between the back and belly) from individuals captured in 2018 (n = 4) on Lake Borkovshchina and its ducts. The revealed morphological differences between individuals trapped in different years confirm the known data on phenetic variability of N. anomalus. The body weight (7.14–8.03 g) and the main parameters (for example, the ratio of tail length to body length was 0.65–0.68) did not differ significantly. Also individuals of N. anomalus did not differ significantly by craniometrical characters (height of coronoid process was 4.04–4.17 mm). In 2018–2019, individuals of the Mediterranean water shrew were trapped in three interconnected lakes, the total length of which with the channels is about 8 km. The shallow and densely overgrown with trees and shrubs channels between the lakes contribute to the dispersal of individuals. According to the results of the 2018 survey, the relative abundance of N. anomalus on Lake Borkovshchina and its channels was 4 individuals / 100 trap-days, and according to 2019 data on Lake Dolzhina and Lake Vechelye — 5.0 and 4.4, respectively. The findings give a reason to suggest the stability of the local population. One of the factors contributing to this phenomenon is the reduction in flood water. To maintain the abundance of the species, it is necessary, first of all, to preserve the shoreline, riparian and aquatic vegetation in lakes. It is advisable to include lakes into the system of protected areas with the status of reserves.