Academic journal article Estonian Journal of Ecology

New Data on the Distribution of the Barbastelle Bat Barbastella Barbastellus in Latvia/Uusi Andmeid Euroopa Laikorva Barbastella Barbastellus'e Leviku Kohta Latis

Academic journal article Estonian Journal of Ecology

New Data on the Distribution of the Barbastelle Bat Barbastella Barbastellus in Latvia/Uusi Andmeid Euroopa Laikorva Barbastella Barbastellus'e Leviku Kohta Latis

Article excerpt

INTRODUCTION

The barbastelle bat Barbastella barbastellus (Schreber, 1774) is regarded as one of the most endangered bat species in Europe. It is included in the Annexes II and IV of the Habitat Directive. The threats to populations of barbastelles are largely unknown. However, due to some specific features of this species, particularly feeding almost exclusively on moths and common use of crevices behind the bark of old or dead deciduous trees, barbastelles are probably especially vulnerable against intensive forest management practices (Rydell et al., 1996; Sierro & Arlettaz, 1997; Russo et al., 2004). The barbastelle bat can be found throughout Europe (Rydell & Bogdanowicz, 1997). In the northern and north-eastern parts of Europe it has been recorded in South Norway (Gjerde, 2008), South Sweden (Ahlen & Gerell, 1989), the western part of Belarus (Kurskov, 1981; Demjanchik & Demjanchik, 2000), South Lithuania (Masing & Busha, 1983; Pauza & Pauziene, 1998; Baranauskas, 2001), and also in Latvia (Busa, 1986; Petersons & Vintulis, 1998). In Lithuania D. Pausa and his colleagues summarized all data of records on barbastelles and suggested that the northern border of the species range lies in the central part of the country (Pauza et al., 2003). There are no published data on the occurrence of barbastelles in Estonia.

Distribution of barbastelles in Latvia

Until the middle of the 1990s, in Latvia there were only a few historical records of single hibernating animals found in caves (2) and in a cellar (Petersons & Vintulis, 1998). During the study on the migration of bats at the western coast of the Baltic Sea a mass capturing of bats was carried out during the autumn seasons of 1985-1992 (Petersons, 2004). Barbastelles, although making up only 0.6% (9 ind.) of all captured bats, were registered at the time of their regular migration over the SW coast of the Baltic Sea. This let us suggest that a summer population of this species should occur in Latvia, probably in the SW part of the country (Petersons & Vintulis, 1998).

In the 1990s and 2000s the use of ultrasound detectors to identify barbastelles proved to be a promising method in the study of the distribution of this species (Ahlen & Baagoe, 1999; Denzinger et al., 2001). While flying barbastelles quite often emit ultrasound calls of two types: louder calls at a peak frequency of 43 kHz and weaker calls at a peak frequency around 34 kHz. Both alternating calls can be easily tracked by means of ultrasound detectors that are equipped with a time expansion sound transformation system (Ahlen, 1981, 1990). An intensive survey with ultrasound detectors in South Sweden resulted in a considerable increase in the knowledge on the occurrence and distribution of this rare bat species (Ahlen, 2003).

In 1997 and 2003 two previously unknown hibernation sites of barbastelles were found in cellars in the central part of Latvia. This was the first evidence on the existence of a population of this species in Latvia (G. Petersons & V. Vintulis, unpubl. data). Both sites were occupied by barbastelles also in the subsequent winters. In 2006 and 2007 we conducted two survey projects on this species, with a goal of figuring out its distribution pattern in Latvia. The detector survey was used as the main method for this study.

The aim of this paper is to present the data on the distribution of the barbastelles collected in 2006 and 2007 and to discuss the distribution pattern of the species in the north-eastern part of its distribution range.

MATERIAL AND METHODS

We used three methods to prove the occurrence of barbastelles: (1) recording of flying bats with ultrasound detectors in suitable summer habitats, (2) capturing of flying bats in summer or autumn near their underground roosts, and (3) inspection of cellars during the hibernation season.

We considered as suitable barbastelle habitats old manors or castles surrounded by parks, deciduous forests, meadows, and pastures as suggested by Swedish researchers (I. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed

Oops!

An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.