Myomimus roachi was recognised as a living species as late as 1959, first in Bulgaria, but was reported under the name M. personatus which actually occupies Turkmenistan and adjacent Iran. In mid-1970, the Bulgarian subpopulation was described as a new species M. bulgaricus. Almost simultaneously, the species name roachi, which was established on Late Pleistocene craniodental material from Cave Tabun (Israel), was shown to be identical with the extant Roach's Mouse-tailed Dormouse, hence the name bulgaricus is a young synonym of roachi (Krystufek and Vohralik 2005).

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

This species is found in a restricted area in Europe, with an area of occupancy (AOO) of less than 500 km², and there have been no recent records from European Türkiye. The vast majority of the habitat has been converted to agriculture, and the remaining areas are severely fragmented and subject to ongoing decline. Further research may show that the species qualifies as Critically Endangered under criterion A and/or B. The population occupying Bulgaria and Greece is roughly identical to 50% of the global population. The species is assessed as Endangered (EN B2ab(ii,iii)) for both Europe and for the EU 27 Member States. The population outside the Europe is also fragmented and probably declining, so no rescue effect would be expected.

The range of Roach's Mouse-tailed Dormouse is one of the smallest among rodents in the Western Palaearctic. The bulk of the distribution is in the lowlands of Thrace in south-eastern Bulgaria (Nedyalkov et al. 2018), western European Türkiye (Kurtonur and Özkan 1991), and eastern Greece, where the presence of this species has been recently confirmed (Kiamos et al. 2019). There are no recent records from European Türkiye.

Out of the European region, the species is known from three localities on the Aegean coast of Anatolia (Türkiye) between Çanakkale and Lake Bafa (Kryštufek and Vohralik 2005). Musser-Holden et al. (2016) estimated the distributional range to be less than 2,000 km². Elevation range is from close to sea level up to 300-350 m (Milchev and Georgiev 2012).

Little is known about this restricted-range species and all published sources agree that Roach's Mouse-tailed Dormouse is rare. It is a hibernating species with the active period from late April till late August-early September though captive dormice remained active until mid-November (Kryštufek and Vohralik 2005). Furthermore, even in summer, some individuals may be lethargic which further adds to the perceived rarity of the species which was only rarely captured in the past (cf. Kryštufek and Vohralik 2005, Nedyalkov et al. 2018, Kiamos et al. 2019). Besides, methods used so far in recording the Roach's Mouse-tailed Dormouse were evidently not appropriate for this species. E.g. ongoing monitoring using nest boxes yielded 259 individual records over three years (2019-2021) in a comparatively small area in Bulgaria (Nedyalkov et al. 2022). A population estimate of 2,226 adult individuals in Bulgaria (Popov and Nedyalkov 2013) should be taken "with a grain of salt" (Nedyalkov et al. 2018). The population is considered to be severely fragmented, as over half of the population occurs in small, isolated patches and may not be viable in the long-term as a result of continuous habitat fragmentation and decline.

Report on habitat preferences are contradictory since Roach's Mouse-tailed Dormouse were captured in diverse habitats: open cultivated landscape, semi-open grassland with shrubs and single trees, lowland riparian forest, deciduous forests, hedgerows, orchards, vineyards and scrubs. Although it is found in some extensively managed agricultural habitats, the species is absent from intensively farmed areas.

The diet is omnivorous and captive individuals preferred insects, but also showed carnivorous habits and consumed fruits and seeds. A single litter is delivered in late April-early May and contains5-14 young (mean = 8.2). Few individuals monitored telemetrically in Bulgaria moved over an area of 2,071-6,646 m², and crossed open habitats, including ploughed fields (Kurtonur and Ozkan 1991, Buruldag and Kurtonur 2001, Kryštufek and Vohralik 2005, Holden-Musser et al. 2016, Nedyalkov et al. 2022).

The Roach's Mouse-tailed Dormouse was much more widespread in the eastern Mediterranean during the Pleistocene and its range demonstrably shrunk since the Late Bronze Age (1600-1300 BCE), presumably as a consequence of habitat degradation (Haas 1959, Kryštufek et al. 2009). The vast majority of habitat suitable for the Roach's Mouse-tailed Dormouse has been converted to intensive agriculture, and what is left is severely fragmented and subjected to ongoing losses (Global Mammal Assessment SW Asia workshop 2005, and author's own observations in Europe). Fragmentation is likely to be accelerated by climate change impacts on the arid habitats of Thrace. Furthermore, the native woodland was in the past replaced in many places with alien tree species, while pastures are cleared of trees and scrubs and maintained open in line with the EU subsidised regulations (Nedyalkov et al. 2018).

The species is not used or traded.

It is listed on Appendices II and III of the Bern Convention. and Annex II of Habitat Directive. In Bulgaria, approximately 1/2 of localities with Roach's Mouse-tailed Dormouse are within the ecological network Natura 2000, and the species is protected and included as VU in the national Red Data Book (Popov 2015). In Greece, the known range for Myomimus roachi does not lie within the ecological network Natura 2000, and has been assessed as CR for the Greece national Red List (D. Youlatos and L.-D. Rammou).

Surveys are needed to determine if and where the species can still be found, and such sites should be strictly protected.