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

Abstract

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, Novopetrivka), 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 captured animal. A map of the distribution of registrations across the territory of Ukraine, which includes 14 localities recorded after 2000, is provided. Today, we can talk about another phantom species, which repeats the history of other phantom bat species that have been reported from Ukraine. However, the body of evidence is quite sound, since it is not based on expert opinion about the audio signals heard, but on the analysis of signals according to their physical characteristics that can be measured. 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 possible errors inherent in the identification systems, which are very typical for the periods of primary biota inventory using newfangled methods. The authors consider registrations of signals of Hypsugo savii as the actual appearance of this bat species, but not in the form of new populations, but as individuals appearing as scouts exploring new territories. Actually, the latter explains the lack of actual findings of this species.

Keywords

• pipistrelles
• habitat dynamics
• species identification
• phantom species
• expansion