European Souslik
Spermophilus citellus (Linnaeus, 1766)
Citellus citellus Linnaeus: Peshev, 1955: 277-327.
Order Rodentia
Family Sciuridae
Conservation status: in Bulgaria: Vulnerable VU [A1c], BDA-II; International: IUCN [A1c], BeC-II, HD-II, IV.
General distribution. The Balkan peninsula, Central Europe (the Pannonian plain), isolated populations in Moldova, the Ukraine, Germany (extinct), Poland (extinct).
Distribution and abundance in Bulgaria. It is found throughout the country, in the mountains at altitudes of up to 2 500 m [1]. In the middle of the 20th century, in favourable conditions, the density reached 16-35 individuals/ha, and at places up to 65 individuals/ha [2] and more. Modern data show a significant decrease in numbers and/or a reduction of the settled area and its disappearance in separate localities.
Habitats. Non-arable areas (abandoned lands, pastures, meadows, etc.), covered with low herbaceous vegetation, on homogeneous, badly sealed water-permeable soils [3]. It does not settle in arable areas, although it enters them for feeding [2].
Biology. A ground species with a diurnal activity. It forms within-populational local groupings ("colonies"), occupying an area of 3-5 ha, in rare cases 100-150 ha, within which the separate animals inhabit overlapping individual areas and maintain a system of nesting and shelter holes [2, 3, 4]. The annual life cycle has a marked periodicity: winter sleep (hibernation), awakening and coupling, pregnancy and lactation, preparation for hibernation. It breeds once yearly. The females give birth to up to 7 young, rarely 9. It feeds on the green parts of herbaceous plants, bulbs, seeds, insects and, rarely, vertebrate animals [6, 2]. It occupies an important place in ecosystems, as a nutrition resource of practically all diurnal rapacious birds and predatory mammals.
Similar species. None.
Negative factors. Ploughing virgin lands and creation of large massifs of arable areas, building, forestation, direct persecution, succession changes in the habitats as a result of the decrease of pasture animal breeding and mostly sheep-breeding.
Conservation measures taken. It is included in the Biological Diversity Act, Annex 2. Some of the mountainous populations are within the national parks Rila and Central Balkan. The planning of the Natura 2000 network of protected territories is adapted to the current state of the species. It is included in the National System for Monitoring Biological Diversity. Monitoring is carried out at the national parks Central Balkan and Rila and in the Rhodopes. Information materials have been prepared (slogans, brochures, billboards) about the necessity for its preservation.
Conservation measures needed. Detailed mapping of the distribution, explanation of the intraspecific structure [7] and assessment of the state of the numbers of local populations and their habitats. Effective application of the Biological Diversity Act for priority preservation of its habitats by working out regional management plans in the context of the programmes for the development of rural regions and, in particular, the implementation of traditional practices for pasture animal breeding.
References. 1. Peshev, 1955; 2. Markov, 1957; 3. Straka, 1961; 4. Paspalev & Peshev, 1957;
5. Nikitina, 1989; 6. Pakij, 1958; 7. Peshev et al., 2004.
Author: Vladimir Stefanov
