According to present taxonomic knowledge, four subspecies are distinguished by Helgen et al. 2009: S. c. citellus; S. c. gradojevici with synonyms karamani and macedonicus; S. c. istricus with synonyms laskarevi and S. c. martinoi which has balcanicus and thracius as synonyms. In a detailed revision of palearctic rodents (Kryštufek and Vohralík 2012) distinguish only three subspecies: s. c. citellus with synonyms istricus, laskarevi and probably also martinoi and balcanicus; s. c. gradojevici with synonyms thracius and macedonicus; and s. c. karamani. The validity of some subspecies should be considered as uncertain until detailed genetic studies are performed.

Global and European regional assessment: Endangered (EN)
EU 27 regional assessment: Endangered (EN)

Declines in area of occupancy and habitat quality are ongoing for this species across its range, and are predicted to increase in upcoming decades. Ongoing habitat destruction has been recorded in new EU member states such as Romania, Bulgaria and also in Serbia, the latter is also expected to face increased grassland destruction in the near future. Especially in EU member states, agricultural intensification continues to negatively affect European Ground Squirrel habitats. Further agricultural intensification is suspected to cause additional decline in extent of occurrence and quality of habitat within the next 10 years. Especially in the western part of the range, high levels of isolation of European Ground Squirrel populations have negatively affected the species: in Hungary, populations are frequently decreasing without habitat elimination or without the size of the habitats decreasing. Many of the large populations are not protected, and the species is generally highly dependent on the anthropogenic management of its habitats, primarily by livestock grazing. Also, genetic depletion of fragmented populations has been observed in Central Europe. Overall, known or suspected population reduction in the past, and suspected future population reduction is likely to be over 50%. Although most of the contractions happened outside of EU member states (Ukraine and Moldova), and the EU countries share the largest and most stable populations of the species (Hungary, Romania and Bulgaria), the assessment for EU27 is the same as for Global assessment, as there are predictions of large future declines in suitable habitat in the region due to climate change, and this could cause population declines of 50%, therefore it is precautionarily listed as Endangered. The species is assessed as EN A3c for both European and EU27 regions.

The European Ground Squirrel is endemic to central and south-eastern Europe, where it occurs at altitudes of 0 to 2,593 m. Its range is divided in two by the Carpathian mountains (Ružić 1978, Říčanová et al. 2013). The north-western portion extends through Czechia, Poland, Austria, Slovakia, Hungary, northern Serbia, and western Romania, whilst the south-eastern portion extends from southern Serbia, North Macedonia and Greece through Bulgaria and southern Romania to Turkish Thrace, Moldova and Ukraine (Panteleyev 1998, Kryštufek 1999).

The European Ground Squirrel has been shown to experience a serious decline. Its population has become fragmented, and extinctions have occurred in peripheral parts of its range in Germany (where it went extinct ca 1985 because of forestry) and Poland (where the last definite autochthonous records date from the end of 1970s, although the species has recently been reintroduced in 2005 (Kryštufek 1999, Matějů et al. 2010, Matějů et al. 2012, Kończak et al. 2014, Wojtaszyn et al. 2015). Although there are still some large and apparently stable subpopulations, there have been many reports of declines, especially in the north-western part of its range; it is also declining in the southern part of the range. In optimal habitat, densities of 18-48 individuals per hectare have been recorded, although lower figures of 5-14 individuals per hectare are also reported (Kryštufek 1999, reviewed in Ramos-Lara et al. 2014).

In Austria, the extent of occurrence (EOO) is approximately 8,600 km², 55 km² of which are inhabited by 25,000-60,000 individuals. The overall population consists of about 80 metapopulations (Enzinger 2017, I.E. Hoffmann unpublished). In a long-term study, population densities during the mating season ranged from 6.3 to 61 individuals/ha (Hoffmann et al. 2003a). Calculated from data in Enzinger 2017, average densities are 4.5-10.9, with 3.1-10.3 in Lower Austria, 11.1-12.2 in Burgenland and 9.1-27.2 in Vienna. Vineyards have become the most important habitat in Lower Austria and Vienna. In Lower Austria, 51% of the 48,76km² area of occupancy (AOO) are vineyards, 24% fallows or field margins, 8% golf courses, grassy airfields and recreation areas, 4% natural grassland, 3% settlement area, 3% heterogenous agriculture with complex cultivation patterns, 2% trade and industrial areas, and 1% lawns. Some colonies are on woodland edges, and <1% occur near gravel pits and on roadsides (Enzinger 2017). The strongest decline in abundance was initiated by the intensification of agriculture in the 1950s, paralleled by the conversion and abandonment of pastures (Spitzenberger 2005). Subsequently, the decline continued due to increasing building activity, e.g. road infrastructure and trade areas (Hoffmann 2003b). In the 21st century, overall abundance in Lower Austria and Vienna ceased to decrease, with some populations growing, whereas others, especially small and/or isolated ones in Burgenland, declined or even disappeared (Enzinger 2017, Schmelzer and Herzig-Straschil 2013).

In Moldova, the European Ground Squirrel is found in the eastern and central part of the country, where 25 colonies have been known recently (Savin et al. 2014). In two populations a hybrid zone between S. citellus and S. suslicus was revealed (Říčanová et al. 2016). Density varies from 2-4 to 10-12 individuals/ha (Savin et al. 2014). According to Savin et al. (2014), the species’ abundance has been continuously decreasing in the last decades, in spite of its protection.

In Romania, since 2005, some 1,100 colonies have been identified, 77% of which in the eastern population. It is most abundant in the eastern (Moldavia) and south-eastern parts (Dobruja) of the country. Colony size varies greatly, from tens to thousands of individuals. A mean spring density of 110 burrows/ha has been recorded in the Bărăgan region (Muntenia), and 136 in southern Moldavia, and even in 220 in Dobruja (Hegyeli, unpublished data). Baltag et al. (2014) found lower densities across Moldavia (mean 15.4 individuals/ha). In western Romania, summer burrow densities of 144/ha have been found, with slightly lower spring densities (projects LIFE09NAT/HU/00384 and LIFE13NAT/HU/000183). Chiefly occupies grasslands used as pastures, but is occasionally found in other habitats, such as river embankments, meadows, roadside strips, fallow land or airports. The vast majority of its Romanian habitats are sheep-grazed. In western Romania, the species (or its suitable habitats) could not be reconfirmed in 29 grids of 10x×10 km (54% of all occupied grids), while this figure was 129 (60%) for regions east and south of the Carpathians (Hegyeli et al. 2012).

In Poland, since 2005, the reintroduction programme has been conducted in six sites, in four of them without lasting success. Currently, the species occurs in two sites and the results of monitoring surveys in 2020-2022 indicated the presence of about 1,000-1,400 active burrows (A. Kepel unpublished data).

In Slovakia, the number of individuals decreased constantly since the 1960s, but in the 1990s there were still some colonies with 1,000 individuals present, however these dropped within a few years after the management changed. During the 2013 monitoring, the number of individuals was estimated at 6,000 – 15,000 in total. In 2019, after thorough monitoring the estimation was around 20,000 animals; it was the result of a two-year project resulting in an increase of numbers in selected colonies in 2018 and 2019 as well. As of 2019, there were 42 localities confirmed with European Ground Squirrel occurrence in Slovakia. However, the number of individuals per colony were even more alarming, as 7,000 individuals inhabited one large colony at Bratislava airport. There were two larger colonies counting up to 1,000 individuals, the rest was distributed among 29 colonies and counted tens of animals, in five localities the colonies shrunk to less than 10 individuals alive and five colonies had less than 20 individuals. In 2020 the project LIFE19 NAT/SK/001069 SYSEL started with the aim for habitat management, setting-up of sustainable food sources, elimination of predation, genetic study and restoration of former colonies. The genetic study identified degraded genetic variability in all colonies except three large colonies with over 1,000 individuals, therefore the translocations were carried out from these to other colonies. As a result of the project efforts, in 2022 the number of individuals increased to 36,000 already, the numbers in small colonies reached at least one hundred individuals (Hapl, 2022 unpublished data). Unfortunately, not all colonies are attended to as needed, as LIFE projects could be carried out only in Natura 2000 sites. There were new colonies established and some were found with few animals still living even though deemed extinct, therefore the translocations of new individuals were carried out. As of 2022 51 colonies were recorded in Slovakia, 40 of them are the focus of the LIFE SYSEL project, where the populations are expected to increase further in the following years.

In Türkiye, the species is restricted to the lowlands of Thrace, where Kryštufek and Vohralík (2005) cites it from 12 localities, at low altitudes, without finding it abundant.

In Hungary, historical data show that two-thirds of the colonies disappeared in the last fifty years, even though one tenth of these were especially large. Decrease of the estimated number of colonies was uneven during this period: there was a slight, gradual decline before 1995 but since then it has declined sharply. Besides, long term data indicate regional differences in population trends. The earliest structural change in the declining trend was observed parallel to the abandonment of mountain slope grasslands, but severe decrease was later documented at the lowland grasslands. Conservation status of the European Ground Squirrel changed from being considered as a pest to being protected in the last century (1982) and later to strictly protected (2012) due to the recognition of such definite decrease. Land use change, especially the abandonment of grazing, was the main cause of colony disappearance, and improved conservation efforts are necessary to stop and reverse these trends (Németh et al. 2018). Based on the results of the European Ground Squirrel Programme of the Hungarian Biodiversity Monitoring System, Hungarian populations of the species have shown significant density decrease since 2000. Density of individuals varied from 1.25 to 150 individuals per hectare but occasionally 250 individuals/ha were also recorded. Development of potential habitat maps based on GIS analysis, made it clear that not only present ground squirrel areas but potential distribution areas (where the ground squirrel is absent at the present) show significant fragmentation and are highly isolated. Although mosaic, fragmented habitat structure does not necessarily lead to the extinction of populations, maintaining habitat patches in at least the present quality and quantity is needed for the survival of the species, to ensure the connection between them (Váczi et al. 2019). Soft-release reintroductions and translocations have been carried out for the last 20 years. Methods used in translocations are based on validated experimental studies (Gedeon et al. 2011, 2012) to help increase longer term success of translocations. In order to have a strong evidence about their long term, positive effect on the trend and conservation status of the Hungarian population, we need further data but experience from the last 20 years has indicated that they may be able to slow down the loss of local populations. Based on these findings we can conclude that the status of the Hungarian population is in an alarming conservation status, but hopefully it can be sustained in the long-term with adequate conservation measures.

In Ukraine the species became extinct from Zakarpatska region, but still survives in Chernivtsi and Vinnytsia regions with population estimates of ca 1,640 active burrows in 2022 (Rusin 2022).

In Czechia occurrence and abundance of the European Ground Squirrel has moderately grown during the last two decades. There were 83 known localities of occurrence in 1990–2001, but by 2000-2001 only 26 colonies still existed (Cepáková and Hulová 2002). Since 2001, there has been regular monitoring of S. citellus. The occurrence of the species was recorded on 35 sites, and a total abundance was estimated to be 3,600 individuals in 2008 (Matějů et al. 2008). That[HZs2] year's Action plan for the European Ground Squirrel in Czechia was adopted by The Ministry of Environment (Matějů et al. 2010). In 2016, the European Ground Squirrel was known from 36 sites, and its total abundance was ca. 5,000 individuals. The European Ground Squirrel distribution was scattered throughout Czechia, with most populations occurring in south Moravia and central and north Bohemia. Olšová Vrata was the most northwestern site of European Ground Squirrel in its distribution area. Since 2016 ground squirrels have been successfully reintroduced at two sites, and populations at five localities were reinforced (Matějů and Brzobohatá unpublished data). European Ground Squirrels were recorded at 40 localities in Czechia in 2020. The overall abundance was estimated to be ca 8,000 individuals, and the total area of colonies was 920 ha. Density varies from about one individual per hectare in vineyards to more than 70 individuals/ha in some airfields (Matějů and Brzobohatá unpublished data). High density was usually connected to sites with an artificial food source. In 2021, the European Ground Squirrel was confirmed at 41 localities, but the overall estimated abundance decreased to ca 6,000 individuals. It is assumed that the main reasons for this decrease were cold and rainy spring weather and the number of summer storms accompanied by torrential rains (Matějů and Brzobohatá unpublished data). In 2022, the situation was very similar. The occurrence of ground squirrels was recorded at 40 localities with ca 6,000 individuals in total. Area of all ​​colonies covered less than 750 ha.

In Serbia the population is disjunct, inhabiting fragments of steppe habitats in the north and mountain pastures in the southeast. Monitoring local population distribution resulted in mapping 130 northern and nine eastern local populations. There have been only two comprehensive population size surveys in the north part of the species range. One covered three local populations, two in Srem and one local population in southern Banat (from 2005 to 2015), and the other one in 20 local populations in the central Banat area (from 2013 to 2015). Population density varied from 1 - 112 individuals/ha in Srem, in southern Banat from 1 - 68 individuals/ha, and from 1 - 88 individuals/ha in central Banat, with an average density of 37.8, 34.3 and 17.2 individuals/ha, respectively (Ćosić N. 2015, Nikolić T. 2019, Nikolić et al. 2020). The estimated densities for the mountain population from southeast Serbia ranged from 7.6 individuals/ha at Besna kobila to 49 individuals/ha at Stara planina (author's unpublished data). The declining trend in active populations on mapped suitable habitats is denoted in central Banat. On the three-year scale, the number of active populations declined from 20 active populations in 2013 to 16 in 2015. The distribution range (regional) in the northern part has been constricted to 70% (Nikolić et al. 2019) and in the south-eastern, 90% (author's unpublished data) in comparison to the local population's historical distribution.

In Bulgaria, the estimated extent of occurrence is approximately 110.000 km². The species has disappeared from the south-western part of the country and from some 10×10 km UTM grid squares in the north-western part. Reduction at the moment occurs as a reduction in the number of colonies, reduction of habitats and stepping stones (Y. Koshev – pers. records). In Bulgaria about 30% of colonies have disappeared, the reasons for this being the intensification of agriculture, the reduction of the number of grazing animals, often stimulated by European funds (Koshev 2022).

In North Macedonia the species is found in an area of 884 ha on Mount Jakupica, where densities (0.8–5.5 individuals/ ha) are lower than those reported elsewhere for the species, and a total population of approximately 2,000 adults (Kryštufek et al. 2012). At least 15 scattered ground squirrel colonies are found in the lowlands of south-eastern North Macedonia (excluding Strumica area), all patchily distributed and embedded between fields and vineyards. These can be attributed to four distinct populations more or less isolated by geographic barriers (Haberl 2010).

In Greece the species is distributed in three separate sub-populations in the northern country. The colonies are extremely small (mean area 6.4 ha) and have very low numbers of animals, with most localities containing less than 10 individuals each (Rammou et al. 2021). The mean population density is 7.4 individuals/ha. During the surveys from 2019–2020 (Rammou et al. 2021), colonies were mostly found in agricultural (cereal crops, alfalfa fields, olive groves) and artificial areas, with a low number of colonies found in natural, seminatural and wetland habitats. Surveys from 2019–2020 (Rammou et al. 2021) revealed a drastic decrease in both distribution area (by 62.4%) and colony numbers (by 74.6%). In Greece, populations of two subspecies (macedonicus and graolojenici) have been lost (B. Kryštufek pers. comm. 2006).

The European Ground Squirrel has quite specific habitat requirements. It occupies open grassland habitat with short grass vegetation. The elevation range is approximately up to 2,500 m. It can be found in natural, semi-natural, and artificial habitats, on light, well-drained soil, and with low underground water presence (Grulich 1960, Jandrekova et al. 2011). Burrows are usually on elevated parts of the flat terrain or slopes (Matějů 2004, Katona et al. 2002). The European Ground Squirrel is present on the steppe and salt step grassland fragments, mountain pastures, short-cut lawns (football fields, golf courses, airfields), and patchy rural landscapes (vineyards and orchards, roadsides, grassy roads, riverbanks, field margins, etc.) (Straschil 1972, Hoffmann et al. 2008, Grulich 1960, Ružić 1978, Kryštufek 1999, Spitzenberger 2002, Matějů et al. 2008, Ramos-Lara et al. 2014, Arok 2015, Ćosić N. 2018). The species is able to tolerate the presence of solitary trees and shrubs in its localities. European Ground Squirrels can also tolerate tall vegetation for a limited time – but in a longer time (two to three seasons), the species perishes in such localities (Ružić 1978, Ramos-Lara et al. 2014), since it prefers short vegetation for tall ones (Kis et al. 1998, Matějů et al. 2011 and 2019). According to Ružić (1978), Poa, Euphorbia, Andropogon, Cynodon, Medicago, Festuca, Chrysopogon, Stipa, and, in mountain areas, also Nardus are plants typical of localities with European Ground Squirrel occurrence. Matějů et al. 2011 identified six distant groups of vegetation types (Cynosurus pastures, undifferentiated grasslands, xerophilous ruderal vegetation with biennial and perennial species, xerophilous natural grasslands, annual vegetation of arable land, acidophilous grasslands on shallow soils) at ground squirrel localities in Czechia.

The species is predominantly herbivorous, feeding on green vegetation and seeds, but also on arthropods (Herzig-Straschil 1976, Dănilă 1984 and 1989, Leššová 2010, Győri-Koósz et al. 2013, Arok et al. 2021). The diet is dominated by different species of legumes (Fabaceae) and grasses (Poaceae). Still, seasonal variation is reported for dominant food sources of plant species, seeds, and insects at different habitat types and management practices (Herzig-Straschil 1976, Dănilă 1984 and 1989, Győri-Koósz et al. 2013, Győri-Koósz et al. 2015, Győri-Koósz et al. 2018, Arok et al. 2021). In addition, the species has several essential ecological functions, including affecting soil properties and fertility via burrowing, providing habitat for other species, and serving as prey for a number of predators (Janák et al. 2013, Lindtner et al. 2018, Lindtner et al. 2020).

Habitat loss, conversion or abandonment of steppe grassland and pasture, and habitat degradation leading to the fragmentation of the European Ground Squirrel distribution area are the main threats to species survival (Kryštufek 1999). The main cause of these changes are due to agricultural intensification or infrastructural and road development. This led to intensive fragmentation and isolation of suitable habitats, and thus the species was forced to occupy semi-natural and artificial habitats – intensively managed lawns reported in Czechia (Cepáková and Hulová 2002; Matějů et al. 2008, 2010, 2019), Greece, Hungary, Serbia, Romania, Bulgaria, and Austria (Rammou et al. 2021, Váczi and Altbäcker 1999, Hegyeli et al. 2014, Arok M. 2015, Nikolić et al. 2019, Nikolić 2020, Baltag et al. 2014, Koshev 2022, Straschil 1972, Hoffmann et al. 2008, Spitzenberger 2005). In Austria, it is therefore largely restricted to vineyards, airstrips, golf courses, sport- and camping grounds and other frequently mown lawns where it is completely dependent on the toleration of the owners (Spitzenberger 2002). Furthermore, in Austria, the intensification of agriculture has led to a decline in population (Spitzenberger 2005). In the Pannonian region of Romania, 40% of known colonies have been affected by transformation to arable land and 17% by constructions since Romania’s EU adherence, often within protected areas. In fact, inclusion in protected areas did not diminish these threats at all (Hegyeli et al. 2014). Destruction of grasslands as a result of agriculture intensification, forest plantations and constructions is still an ongoing cause of local extinctions, and an increasing threat in all lowland and hillside areas of Romania, even more so since grassland protection and nature conservation laws are rarely enforced. Baltag et al. (2014) found pasture degradation, building up and flooding to be the most significant threats for ground squirrels in eastern Romania. In the Voivodina region of Serbia, populations are also fragmented due to habitat conversion and infrastructure, and the small patches of suitable habitat are often outside of protected areas (Nicolić et al. 2019). In Bulgaria, colonies are threatened by building of different types resulting in fragmentation (Koshev 2008 and 2022). The changes in grazing intensity and its subsequent succession of open short-grass habitats to tall-grass or shrubs also induced negative population trends and even loss of local populations. In Bulgaria, pasture abandonment has led to a serious decline of habitats (Stoychev et al. 2004, Koshev 2022). Abandonment of cattle and sheep grazing results in further degradation of habitats in Ukraine and Moldova. Kryštufek et al. (2012) found the North Macedonian population to be threatened by pasture abandonment, spread of shrubs and burning. In post-EU accession Hungary, the drastic decline of livestock and subsequent abandonment of grazing has led to sometimes irreversible deterioration of grassland habitats, leading to local extinctions or serious population declines. In Romania, many pastures traditionally grazed with cattle have recently seen a shift towards sheep grazing, leading to overgrazing and a more monotonous habitat composition, which may affect the species. Populations from Hungary, Austria, Slovakia and Czechia are highly dependent on the conscious and targeted management of their habitats, especially since grazing activity has shown a remarkable decrease with the reduction of farm animals, and since many colonies live in anthropic habitats such as airfields or golf courses (e.g. Matějů et al. 2010a).

Food production and use of pesticides can directly or indirectly cause species loss (Ćosić N. 2015). In Romania direct persecution is still an important factor: there is a high number of pest control firms which also undertake European Ground Squirrel control by means of poisoning and gassing of burrows, and in some places water management authorities use gassing of burrows to destroy populations on river embankments (Fülöp and Hegyeli 2016). In Bulgaria colonies are threatened by rodenticides as well (Koshev 2022).

The role of fragmentation has been suggested by Řičanová et al. (2011), with important differences in allele frequencies between eastern and western populations. Ćosić et al. (2013) have found that despite heavy fragmentation in Voivodina, genetic variation was higher than that of peripheral populations in Central Europe. In Slovakia, a recent genetic study proved degraded genetic variability in colonies with a small number of individuals due to inbreeding. Such colonies are prone to diseases, small number of offspring and a lower success of hibernation. High level of fragmentation also increases the risk of irreversible population extinction without the chance of natural recolonisation across the whole distribution area. Another important factor for different levels of genetic diversity experienced in Central Europe (Slimen et al. 2012) has been the effect of different landscape histories and the corresponding region-specific socio-economic development due to distinct agricultural systems (Gedeon et al. 2017).

Illegal ploughing of colonies is one of the major threats for European Ground Squirrels in Bulgaria, Ukraine, Moldova and Romania (Koshev 2022, Rusin, unpublished data, Hegyeli et al. 2014). At least one colony (out of 11 known) was destroyed in Chernivtsi Region in 2022. Two projects aimed at ground squirrel and Saker Falcon (Falco cherrug) conservation (LIFE09NAT/HU/00384 and LIFE13NAT/HU/000183) have both had several protected target populations destroyed by illegal ploughing in Romania, despite continuous communication between the project staff and authorities. European Ground Squirrels often survive closer to villages (where local rural people still keep their herds) where they often fall victim to cats and dogs.

Rapid development of renewable energies places new threats to European Ground Squirrels. In Greece one of the largest colonies is under threat of total extinction with the development of Wind Power Plant on Mount Vermio (Rammou et al. 2022). In Poland, it is difficult to find areas with dry grasslands for the reintroduction programme, due to the high demand for such areas for the construction of solar power plant farms (A. Kepel, unpublished 2023).

The increased intensity and frequency of heavy rains and flood occurrence, especially in combination with moderate winter temperatures, can increase groundwater levels, and lead to the drowning of animals during hibernation (Janȧk et al. 2013). In some European Ground Squirrel localities in Czechia and Slovakia it was documented that torrential rains and rapid snow melting could cause major decrease of population abundance or even extinction of European Ground Squirrel colonies (Havelík 2002, Matějů 2008, Matějů et al. 2019, Hapl and Matějů unpublished data). Flooding has also been recorded as a serious threat in Ukraine and Moldova (Rusin, unpublished data). Németh (2010) additionally reports that even higher winter temperatures can harm the survival of individuals during the hibernation period.

The degradation of habitat quality due to changes in habitat management was reported in Bulgaria, Romania, Macedonia, Slovakia and Serbia (Demerdzhiev et al. 2014, Y. Koshev – unpublished records, Koshev 2008, Kryštufek et al. 2012, Baltag et al. 2014, Arok 2015, Ćosić 2018, Nikolić 2020). This can lead to a lack of food supply in large monocultural grasslands with low diversity of plants and insects. Also, the spread of alien plants (fe Asclepias syriaca in Ukraine and Solanum elaeagnifolium in Greece) results in further degradation of habitats (Rammou et al. 2022, Rusin, unpublished data).

Hybridisation with S. suslicus occurred in the past in Ukraine and Moldova, but does not pose any threat now due to the extinction of S. suslicus in most regions.

An unexpected threat is the agri-environmental subsidy schemes from the funds of the European Union. In Poland, for example, they are focused on the protection of types of natural habitats or bird species, and do not take ground squirrels into account, due to the small number of their sites. Farmers, in order to receive these subsidies, are obligated to late date first mowing, which is very unfavourable for ground squirrels and has already led to the disappearance of some of the reintroduced populations in this country (Kepel 2015).

The species is not utilised or traded.

The species is listed in the Resolution 6 of the Bern Convention and Annexes II and IV of the EU Habitats and Species Directive. It is currently a protected species in all countries where it occurs and included in the National Red Books of Ukraine, Moldova, Romania, and Greece. Occurs in several protected areas, however its conservation should always include pasture management. Lack of grazing on some protected areas resulted in population declines and extinctions.

The EU Action Plan for the European Ground Squirrel was published (Janák et al. 2013), but national and regional action plans must be drafted. For example, the Action Plan for European Ground Squirrels in Czechia has been implemented since 2008 (updated in 2020 – Matějů and Matoušová 2020). The Action Plan for the European Ground Squirrel in Bulgaria was prepared, submitted to the Bulgarian government, and has been approved after six years of delay, in 2022 (Koshev 2022). Also, there was a regional plan in lower Austria to recover the population by maintaining extensive and high-quality habitat implemented through the Agro-ecological measures (AEM), which was successful until AEM subsidies were shifted for other purposes (ÖPUL-Maßnahme Ziesel 2015). Landscape-level conservation planning should be adapted across species distribution areas (Janák et al. 2013, Nikolić et al. 2019, Rammou et al. 2021). This spatial approach will assist in protecting and revitalising open grassland habitats and improving their connectivity. Habitats outside protected area networks or Natura 2000 habitats should become extensions to these conservation networks, or their land use conversion should be prohibited (1.2). The initial phase for landscape-level conservation is mapping of occupied or available habitats. A good example is those mapped in EU countries for the Natura 2000 programme, but also a habitat mapping campaign was successfully implemented in Serbia (Arok 2015, Ćosić 2018, Nikolić 2020). Furthermore, to ensure the survival of isolated populations while preserving 90% of genetic diversity and avoiding the harmful effects of inbreeding, it is necessary to ensure the MVP of 300 individuals over 50 years (Ćosić 2015). Also, one must consider maximal species dispersal capacity and individuals’ within-habitat movement (Spitzenberger 2002, Hoffmann et al. 2008, Kachamakova and Koshev 2018, Nikolić et al. 2019). To meet this requirement within the mapped habitat networks, the size of grassland habitats needs to be extended or the presence of transitional elements (preferably short vegetation) enabled (e.g. between occupied or suitable habitats) or habitat management improved (Nikolić 2019, Rammou et al. 2021). Habitat management should be based on habitat quality assessment, e.g. quantification of available resources, habitat productivity, complexity, and heterogeneity (Nikolić et al. 2020, Arok et al. 2021, Rammou et al. 2021). The results of the habitat assessment should then be used to make management decisions and, if needed, improve habitat conditions, or prepare unoccupied habitats for reintroduction. Several successful reintroductions have been conducted in: Czechia and Slovakia (Matějů et al. 2010 and 2012), Poland (Matějů et al. 2010 and 2012, Kończak et al. 2014), Hungary and Romania (LIFE13NAT/HU/000183) and Bulgaria (Koshev et al. 2019).

Educating and raising the public's awareness of the functional role of European Ground Squirrels as ecosystem engineers or resources for predatory species is of great importance, as population loss also threatens the survival of several other animal species. In 2005, the species was reintroduced to Poland by the NGO PTOP Salamandra, and is still continuing. There are currently two stable wild populations in the country (Wojtaszym et al. 2015, A. Kepel unpublished 2023). In 2006 a project was initiated to reintroduce the species to Germany (H. Meinig pers. comm. 2006). Several reintroductions have also been made in Bulgaria at different altitudes, but with variable results (Koshev et al. 2019, Kachamakova et al. 2022). Research is needed to determine population status and trends, ecological requirements, potential threats, and appropriate conservation measures.