Savi’s pipistrelle (Hypsugo savii) in Ukraine: analysis of records and evidence of expansion

The paper is devoted to the records of a species that until recently has been considered to be limited to the southernmost territories of Ukraine (the southern coast of the Crimea), but for which a number of facts of expansion in the northern direction have been revealed. Savi’s pipistrelle is a rare species that should be the object of attention. Such facts were recorded by the authors using US-signals for a number of quite different places from the southern regions of Ukraine, in particular from the Azov Sea districts of Zaporizhzhia Oblast (Botieve), from Kherson Oblast (Askania Nova) and from the northern regions of the Carpathians (Dolyna). The records belong to the period of intensive ultrasonic monitoring data of bat fauna in 2017–2018. All records have a number of similarities described in the article, in particular: a) belonging to the southern territories, b) predominance of records in spring or autumn, c) virtually all records were made in urban landscapes. In fact, we can talk not about the species’ findings, but about the registration of signals similar to that of the species. The only recent actual find, the description of which contains a number of dubious facts, is an indication of the detection of a hibernating Savi’s pipistrelle in the Sevastopol youth centre. The details of signals corresponding to Hypsugo savii. Similar records have been reported from a number of Carpathian regions of Ukraine, but also without a single animal alive or dead to prove it. A map of the distribution of registrations across the territory of Ukraine is provided. Today, we can only talk about another phantom species, which to some extent repeats the history of other phantom bat species that have been reported from Ukraine. In addition to the three key features of the records mentioned above, which indicate the possibility of such finds, it is important to talk about the errors inherent in the identification systems, which are very typical for the periods of primary biota inventory using newfangled methods. The authors consider registrations to be the actual appearance of a species, but not in the form of new populations, but only of individuals as scouts exploring new territories. In fact, this is the only way to explain the lack of actual findings of this species.