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Abstract. The authors report the state of the terrestrial vertebrates of Romanian and Bulgarian Dobrogea. Five amphibian species, eight of reptiles, 159 of birds and 39 mammals species were inventoried. Some of them are characteristic to the steppe areas, in which Dobrogea is included, and others (as amphibians) have a limited distribution, around water flows, pools and lakes. Some of the observed or collected species have populations which can be compared in the two parts of Dobrogea, while the others (e.g. Crocidura suaveolens, Mesocricetus newtoni, Microtus arvalis) have populations more numerous in the Bulgarian Dobrogea, this thing indicating that there are several undamaged habitats and a low anthropic pressure than in the Romanian one.Résumé. Dans le cadre du contrat de collaboration roumaino-bulgare des années 2008-2009, soutenu par les Ministères de la Recherche Scientifique des deux pays, on a étudié les vertébrés terrestres de la Dobrogea roumaine (départements de Tulcea et Constanþa) et de la Dobrogea bulgare (départements de Silistra et Dobrich). Au cours des deux années on y a observé, prélevé ou inventorié (sur la base des informations de terrain) un nombre de 211 vertébrés terrestres: 5 espèces d'amphibiens, 8 de reptiles, 159 d'oiseaux et 39 de mammifères. Les amphibiens y sont les vertébrés avec la plus réduite biodiversité, le plus grand nombre d'espèces appartenant à la classe des oiseaux. Pour chaque espèce on a précisé le statut de protection, les amphibiens figurant dans les annexes des OUG 57/2007 de la législation roumaine concernant la conservation de la biodiversité et de la loi no. 77/2002 de la législation bulgare, tandis que sur le plan international -dans les annexes de la Directive 92/43 EEC sur la conservation des habitats naturels, de la faune et de la flore sauvage. Les autres espèces de vertébrés jouissent d'une protection légale similaire, sauf un petit nombre d'espèces sans statut actuel de protection. Sur la base des résultats des observations et des prélèvements, nous considérons que l'état des écosystèmes de la Dobrogea bulgare est plus proche de l'état naturel, que ceux de la Dobrogea roumaine. Cette situation se reflète dans les populations (plus nombreuses en Bulgarie) de certaines espèces de vertébrés, ce qui prouve la valeur de ces espèces en tant que bioindicateurs, dans le cas de la Dobrogea roumaine la pression anthropique étant plus forte sur les écosystèmes naturels. Dans les deux pays des aires protégées existent, mais leurs superficies peuvent croître, afin d'agrandir leurs chances de constituer des refuges, pour conserver le fond faunistique de quelques espèces rares ou périclitées: Mesocricetus newtoni, Spermophilus citellus, Mustela eversmanni, Vormela peregusna etc.

We report the changes in the distribution of three alien mammal species in Bulgaria, the coypu Myocastor coypus, the muskrat Ondatra zibethicus, and the raccoon dog Nyctereutes procyonoides after their entry into Bulgaria in the fifties and sixties of the last century. The data has been summarised from field surveys, reviews from scientific literature, analyses from official databases of national institutions and organizations, databases compiled from volunteers and hobbyists, etc. After its introduction in 1953, M. coypus rapidly spread in Bulgaria and there are more than 417 records of the species. Today it is the most widespread invasive mammal in the country. O. zibethicus was introduced in 1956, and is known from only 22 records. However, this species was able to cross the physicogeographic barrier of the Balkan Mountains in 2007, which is a strong evidence for its invasive capabilities in the territory. The first observations of N. procyonoides were reported in 1968. There are currently 75 records of the species coming from almost the entire territory of Bulgaria. The majority of the records (77.4%) are between sea level and 199 m a.s.l. and 56% of them are in national protected areas. The most frequently observed negative impacts are described and recommendations are made for further study and reducing the populations of the invasive mammals.

Grey voles (subgenus Microtus), widespread in Eurasia, may be important pests and could cause serious damage to agricultural grain fields. In Bulgaria two morphologically similar species are present (Microtus arvalis Pallas, 1778 and M. rossiaemeridionalis Ognev 1924), which are impossible to identify in the field. Despite their importance as pests, very little is known about their current status and distribution. Here we cotributed new data - based on karyological examination of 27 individuals of voles. We summarized all available information on the distribution of the voles – 20 published and 11 unpublished locations. Both species co-occurred together in north Bulgaria; in Thrace and the SE only M. rossiaemeridionalis is distributed. Microtus rossiaemeridionalis seems to occupy lower elevations, while in the mountain areas (above 1000 m) only M. arvalis is found, which corresponds well with the data from neighboring countries. The taxonomy of both species in Bulgaria is discussed.

Here we summarize all available data about dormice (Gliridae) in Bulgaria, published one and our own observations, collected in the last 20 years. Four species are found in Bulgaria - the Forest Dormouse (Dryomys nitedula), the Edible Dormouse (Glis glis), the Hazel Dormouse (Muscardinus avellanarius) and the Roach’s Mouse-tailed Dormouse (Myomimus roachi). Altogether we collected 1200 records from 283 locations. A database has been created in which every single record is kept. The most common and widespread species are the Edible (G. glis) and Forest Dormouse (D. nitedula), found in 212 and 139 locations respectively. They inhabit mainly the deciduous and mixed forest in the country. The Hazel Dormouse (M. avellanarius) is found in 77 locations, the bulk of them are in the mountains, but there are some locations along the Danube and southeast Bulgaria. It prefers woods with a well-developed understorey. The Roach’s mouse-tailed dormouse (M. roachi) is the rarest one - found in 26 locations in southeast Bulgaria. In contrast to the other dormice, it avoids woods and lives in semi-open habitats with shrubs, tree lines, and islands in grasslands and agricultural fields. There are several anecdotal reports of the Garden Dormouse (Eliomys quercinus) but no hard proof exists for the presence of this species. We discussed the patterns of distribution, conservation status, and coexistence of Bulgarian dormice.