Nyctalus lasiopterus (Schreber, 1780)

Vlaschenko, Anton, Kravchenko, Kseniia, Prylutska, Alona, Ivancheva, Elena, Sitnikova, Elena & Mishin, Alexander, 2016, Structure of summer bat assemblages in forests in European Russia, Turkish Journal of Zoology 40 (6), pp. 876-893 : 886-887

4.1. Inventory of N. lasiopterus status

Our focal species, N. lasiopterus , was confirmed only in one reserve. We caught young bats, meaning that a breeding micropopulation still exists in the Voronezhsky Reserve. However, we caught the bats at a different location than that recorded in the 1960s. The exact information about the location of roost sites was found in the archive of the reserve. It was found that the forest plot where the roost was located, on the northern border of the Tolshy village, was cut down in the 1970s. However, it was only several hectares in size, and it is known that species of the genus Nyctalus can use dozens of tree roosts during the summer season ( Boye and Dietz, 2005) and N. lasiopterus moves up to 100 km per night ( Popa-Lisseanu et al., 2009). It is clear that the loss of this roost tree did not have an impact on the species moving from the plot where it was recorded. Most probably this colony moved around the whole reserve area, or even the whole Usmansky Bor forest. It is important to note that on satellite images the border between the protected area of the reserve and the management part of the forest is clearly visible. The whole natural area of the reserve area is in the north and there is a patchwork of clear cuttings in the south. We hypothesized that forest harvesting was the main factor for the decline of local N. lasiopterus populations (Vlaschenko et al., 2010) in forest-steppe oak forests. This means that more than 80 years of strictly protected management on 30,000 ha of the Voronezhsky Reserve has maintained a breeding micropopulation of N. lasiopterus .

Currently this record of a breeding micropopulation of N. lasiopterus is only the second known for the East European part of the forest-steppe nature zone. The other breeding micropopulation exists in Samara Bend on the Volga River ( Smirnov et al., 2014), 720 km to the northeast. In the Ukrainian part of the forest-steppe zone this species has been listed as extinct (Vlaschenko et al., 2010, 2012). Only one location of a breeding micropopulation of N. lasiopterus is currently known in Ukraine, in the north in a forest nature zone ( Gashchak et al., 2013), and this location is 650 km southwest of the Voronezhsky Reserve. The next known breeding micropopulation to the west is located more than 750 km to the southwest in Hungary and the south of Slovakia ( Uhrin et al., 2006; Estók and Gombkötő, 2007; Estók, 2011).

N. lasiopterus was not confirmed in the “Bryansky Les” and Oksky Reserves during our study. Closer examination of the record of N. lasiopterus from “Bryansky Les” makes us think that the record is questionable. It was a dead bat that was found on the ground in 1983 ( Shpilenok et al., 1997), but the finder was not a bat expert and he did not take a photo, so we think there is very little chance that it was really N. lasiopterus . The bat research in the reserve in the 1990s and 2000s did not confirm the species’ presence ( Sitnikova et al., 2009). In general though, local researchers in the Bryansk region think that N. lasiopterus is not rare, so we cannot ignore this information ( Prokofev and Gorbachev, 2010). However, those conclusions are based on acoustic surveys performed using the iBats monitoring car transect method ( Prokofev and Gorbachev, 2010). The ultrasound detector model (Tranquility Transect) and recording regime (320 ms) were not sufficient to get a record of required length and quality of sound for exact identification. Our opinion is that the iBats car transect method is not the proper way to identify this species. Confirmation requires the use of the standard method described by Estók and Siemers (2009). We think that amateurs involved in the iBats program in Russia could not properly identify this species.

In the Oksky Reserve, VP Ivanchev showed us the group of trees where N. lasiopterus was recorded and we carried out mist-netting in the surrounding area. The previous record (♀ ad, ♀ sad of N. lasiopterus in a colony of 66 N. noctula) was on 13 August 1987 and these could have been migratory individuals from near or distant locations ( Ivancheva and Ivanchev, 1989). It is also well known that N. lasiopterus can move up to 90–130 km per night ( Popa-Lisseanu et al., 2009) between roosts and roosting and hunting habitats during the breeding season. In autumn migration these could be significantly longer distances. On the other hand, the lack of records of N. lasiopterus in these 2 reserves confirms the idea that this species is rarer than is suggested in current reviews ( Dietz et al., 2009). There is a misconception that sites in this geographical region where individuals of N. lasiopterus were caught in the past are still used by a breeding micropopulation. Our negative results in “Bryansky Les” and the Oksky Reserve suggest that one record of N. lasiopterus is not enough to confirm the species’ presence. In this study we present new facts in order to reevaluate the IUCN status of N. lasiopterus to a more threatened category. We consider N. lasiopterus to be extinct based on our mist-netting results and the IUCN recommendation: ‘A taxon is presumed “extinct” when exhaustive surveys in known and/or expected habitat, at appropriate times (diurnal, seasonal, annual), and throughout its historic range have failed to record an individual’ ( IUCN, 2011).