VARIATIONS IN THE MOUND SIZE OF MOUND-BUILDING MOUSE, MUS SPICILEGUS BETWEEN BULGARIA AND MOLDOVA

R. Metcheva, A. Larion, D. Simeonovska-Nikolova, V. Nistreanu, M. Beltcheva

Abstract: The mound-building mouse, Mus spicilegus is endemic to Europe, adapted to agroecosystems. In autumn, mound-building mice build complex mounds and supply them with seeds. In these mounds, they spend the winter. The mounds have several functions, such as food storage and thermoregulation. Previous studies demonstrated that the mounds vary in size among geographical populations. In this connection we examined whether climatic differences between Bulgaria and Moldova influence the size of the mounds. To describe variations in mound size, mounds were measured and excavated in several locations in Bulgaria and Moldova in autumn and spring between 2000 and 2013. In all studied fields, crops were harvested prior investigations and the habitats were in succession on the place of agroecosystems of sunfl ower, wheat and corn crops as well as on the boundary strips of the agroecosystems. The comparison between mounds in Bulgaria and Moldova was made on the basis of their length, width, height, depth, number of inhabitants and collected plant material. Data on mound size between sampling localities in Bulgaria and Moldova were compared by Mann-Whitney U test. Spearman rank-order correlation (rs) was used to examine the relation between mound size and number of inhabitants. In general the length, width and height of the mounds in the two countries had similar values. However, in Moldova mounds were significantly deeper than those in Bulgaria and number of mice per mound was significantly larger than this in Bulgarian population. Mound size was dependent on the number of inhabitants. The reasons for size differences of mounds are discussed in the context of their adaptive significance.

Keywords: agroecosystems; animal architecture; mounds; Mus spicilegus; population differences

Date published: 2017-10-26