The Roach’s Mouse-tailed Dormouse (Myomimus roachi, Bate 1937) is endemic to the Western Palearctic (occurring in SE Bulgaria, Turkish and Greek Thrace, and western Anatolia) and is one of the less known mammals within the region. There is no information about its biology and ecology in the wild. In the course of the past 3 years (2019-2021), we conducted intensive research on a small population situated in southeast Bulgaria (Sakar mountain). The population was regularly monitored during the active time of the species. To study its ecology and biology we used a combination of nest boxes, live traps and camera traps. During this period, we collected 259 records of sex, age, and weight. Those bigger than 10 g. were microchipped.

The active period for the Roach’s Mouse-tailed Dormouse lasts between April and September. Males emerged first from hibernation at the end of April (24^th of April - the earliest registration). During this short active period, the dormouse breeds only once, the litter size being between 5-9 young. The first young appeared at the end of June. We observed a summer dormancy (estivation); the adult males became less active and went in the estivation first. The last active dormice were observed in the first ten days of September.

Here we also present data about the population numbers and dynamics, age, and sex structure of Roach’s Mouse-tailed Dormouse in the study area.

Nedko Nedyalkov

Oral presentation at the 11^th International Dormice Conference 2022