ISSN 2519-8513 (Print) Biosystems ISSN 2520-2529 (Online) Biosyst. Divers., 26(3), 188–200 doi: 10.15421/011829 Diversity Steppe rodents at the edge of their range: A case study of Spalax microphthalmus in the north of Ukraine I. Zagorodniuk, M. Korobchenko, V. Parkhomenko, Z. Barkaszi National Museum of Natural History, National Academy of Sciences of Ukraine, Kyiv, Ukraine Article info Zagorodniuk, I., Korobchenko, M., Parkhomenko, V., & Barkaszi, Z. (2018). Steppe rodents at the edge of their range: A case study Received 26.06.2018 of Spalax microphthalmus in the north of Ukraine. Biosystems Diversity, 26(3), 188–200. doi: 10.15421/011829 Received in revised form 07.08.2018 Based on results obtained during 2000–2018 by field research, polls of colleagues, and OSINT analysis, features of distribution of Accepted 11.08.2018 the greater mole rat Spalax microphthalmus in the eastern forest steppe of Ukraine were considered. The studied part of the species’ range is unique and represents the northern range edge of the entire Spalacidae family and of European steppe faunal assemblages in National Museum general. In total, data on 146 record localities were amassed, including 13 localities in the fragmented and 133 in the continuous part of of Natural History, NAS the range. The offshoots of the Central Russian Upland in the valley of the Psel river (east of Sumy Oblast) are the sites with the highest of Ukraine, Bohdan density of settlements, while the species’ type biotopes are steppe balka slopes. The abundance of the greater mole rat decreased from Khmelnytsky st., 15, Kyiv, 01601, Ukraine. the east to the west, and its colonies are the most fragmented along the Dnipro River. The species occurs in steppe and meadow habitats Tel.: +38-066-210-57-23. of an area of at least 20–50 ha. Analysis of the current and former distribution of the greater mole rat revealed that the species range E-mail: [email protected] contracts from the west; earlier it was a common species in different regions of the Middle Dnipro Area (including Kyiv city), but the current range edge runs along the line connecting Buryn – Nedryhailiv – Lokhvytsia – Myrhorod – Hadiach – Zinkiv – Zaliznychne. Isolated settlements exist in adjacent territories, particularly in Ichnia Raion of Chernihiv Oblast, and Lubny, Khorol, and Kobeliaky Raions of Poltava Oblast. The study showed that the species’ range contracted by two times to 35,000 km2 for the last 100 years, which includes only 430,000 ha of suitable habitats (15% of the range), allowing the existence here of 86,000–215,000 individuals. In fact, the species remained only in habitats that have been minimally affected by arable farming and other forms of active agricultural use. Besides, the species shows a clear confinement to habitats located near human settlements such as untilled lands, pastures with moderate grazing, waste and neglected lands, which constitute a separate group of transformed and semi-natural habitats. Formally, this allows the greater mole rat to be considered as a synanthropic species, because its inhabited biotopes, beside the zone of offshoots of the Central Russian Upland, have remained only near villages and along roads. The species also has an important biocoenotic role due to its burrowing activity and as prey of predatory birds (e.g., of the long-legged buzzard and Eurasian eagle owl) and mammals. The feeding period of the offspring of these predators generally coincides with the aboveground activity of mole rats, which lasts during May–July with a peak in June. Aboveground activity is mainly related to the resettlement of mole rats to new sites and dispersal of the young, due to which they became victims of predators. Keywords: Spalacidae; geographical distribution; fauna dynamics; steppe biocoenosis; Eastern Europe. Introduction bution range and disappeared from many localities. However, data on distribution of the greater mole rat in the region have been rather Mole rats (Spalax) are highly specialized subterranean mammals ambiguous from the very beginning. In particular, as stated in V. Ave- and a part of steppe faunal assemblages (Zagorodniuk, 1999). These ani- rin’s review (Averin, 1915: p. 32), the greater mole rat is “quite common mals are clearly related to steppe communities and are not only their in our governorate … especially in its eastern part, where it substitutes indicator species, but also ecosystem engineers mainly due to their burro- the European mole. To clarify the borders of its distribution to the north wing and foraging activities (Andersen, 1987; Hagenah & Bennett, and west might be an interesting issue.” Later, in O. Migulin’s review 2013). Recent reduction of natural habitats is especially serious in the (Migulin, 1928: p. 175) it was stated: “The mole rat is widely distributed case of steppe and steppe-like grasslands, including those in Eastern in the former Kharkiv Governorate, although in its northwest part it less Europe (Cremene et al., 2005; Habel et al., 2013). abundant than in the southeast, where some fields are densely burrowed by The distribution of spalacids is restricted mainly to the southern mole rats.” The situation has not changed since. The last reviews indica- regions of Eastern Europe (Reshetnyk, 1941), but also reaching northern ting the disappearance of the greater mole rat in the western parts of areas up to the northern parts of the forest steppe zone, where they Poltava Oblast were published by B. Golov (1975). Later data are inhabit slopes of uplands, where, due to exposure, aridity and other unknown. The aim of the present paper is to study the current features, generally southern-type communities are formed. In the research distribution of the greater mole rat within the forest-steppe zone in the area (to the east of the Dnipro river) only a single mole rat species occurs – northeast of Ukraine based on records dated 2000–2018. Additionally, the greater mole rat Spalax microphthalmus Guldenstaedt, 1770 – which we aim to determine the regions with the highest density of settlements, significantly simplifies the taxonomic attribution of collected faunal data to describe the species’ typical habitats, clarify the borders of its range, (Korobchenko & Zagorodniuk, 2009). the rate of range contraction and the level of range fragmentation. Research into the distribution of mole rats in northeast Ukraine can give answers on where steppe complexes can be preserved and what Material and methods role mole rats play in such communities. Under the influence of total transformation and fragmentation of natural habitats, many species, and In terms of biogeographic division, the research area covers regions especially steppe ones, have significantly contracted their former distri- of the East European deciduous forest and forest steppe zone (1.2.b) to 188 Biosyst. Divers., 26(3) the east of the Dnipro river (subarea 1.2.bb after Szczerbak, 1988). Distribution and biotope analyses. Field research was carried out in In general, the research area lies between the Desna, Dnipro, Orel, and 2000–2018 in the territory of Sumy, Chernihiv, Poltava, and in the Siverskyi Donets rivers within Ukraine, and it borders with the Central northwest of Kharkiv Oblasts, mainly in natural habitats. Data available Russian Upland in the northeast. from literature sources were also analysed, among which it is worth Field diagnostics based on molehills. Only two species of subterra- mentioning reviews by E. Reshetnyk (1941) and B. Golov (1975). nean burrowing mammals occur in the studied area, namely the greater Additionally, polls of colleagues working in the region (Poltava, mole rat and the European mole. The molehills of these species essen- Hadiach, Sumy, Nizhyn, Konotop, Kobeliaky, and Krasnokutsk cities tially differ by the size and volume of excavated soil. Besides, molehills and more than 30 villages) were also conducted. Data were collected also differ by patterns of location and biotope types where they can be not only concerning record localities, but also specifics of biotopic dist- found. Molehills of S. microphthalmus are usually located in a line of ribution of mole rats and their sightings on the surface and in leavings of 20–30 hills with a distance of 2–3 m between them, while molehills of predators. the European mole are located chaotically in compact groups. The dia- In different periods and seasons, together with our local colleagues meter and volume of molehills also vary from 50–90 cm and 5–20 l in we conducted six route censuses by vehicle in general direction of the the greater mole rat, and 25–40 cm and 2.5–3.2 l in the European mole transect Kyiv – Pyriatyn – Poltava – Kharkiv, during which localities (own data; Kutseryb, 2011). Although, molehills of the mole rat were with dense settlement or their absence were recorded. These data were similar to that of the European mole in several cases (Fig. 1a), the latter used for the zones of sporadic and continuous distribution, and in some excavates fine-grained soil, while the greater mole rat excavates soil cases for creation of an inventory as well. Additionally, OSINT analysis clouts of 3–5 cm (Fig. 1c), which are especially visible at the top of the was conducted, based on which two records of mole rats were obtained. molehills (own data). Moreover, these two species also differ by the Finally, all available museum collections of Ukraine were revised. type of habitat they occupy: the European mole occurs in forests and Records were mapped by GIS tools using the QGis application. floodplain meadows, while the greater mole rat prefers balkas with All records were described according to a similar scheme including the steppe and meadow communities (interfluves between large rivers) names of administrative units, closest human settlements or nature con- (Fig. 1a). In several cases, the diameter of the burrow is also informative, servation areas, date of observation, biotope, and the observed object which is about 5–8 cm in the mole rat (Fig.