Roosting behaviour of the greater noctule Nyctalus lasiopterus Schreber, 1780 (Chiroptera, Vespertilionidae) in Hungary as revealed by radio-tracking

Abstract

Nyctalus lasiopterus is one of the rarest bat species in Europe and there is little information on the roosting requirements and habitat preference of this species. In recent times two papers have been published regarding carnivory of small birds by the species (Dondini and Vergari 2000, Ibanez et al. 2001). In these articles some notes are also presented on the roosts of the species and Ibanez et al. (2004) give a summary on the knowledge of the ecology of N. lasiopterus, including data on roosting behaviour. N. lasiopterus is known as a typical tree-dwelling bat, roosting in trees all year round. It has been found in the cavities of very different trees, including both deciduous and coniferous species (Ibanez et al. 2004). Dondini and Vergari (2000) reported the species from bat boxes fitted on beech trees (Fagus sylvatica) in Tuscany, Italy. Ibanez et al. (2001, 2004) found 11 tree roosts of N. lasiopterus in a park in Sevilla, eight of which were in Platanus spp. and three in Sophora japonica. They also described a maternity colony of 80 specimens roosting under the dried leaves of three palm trees (Washingtonia filirifera) in Jerez de la Frontera, Southern Spain. Beck and Gebhard (2000) reported on an unusual occurrence of the species: a female specimen was found in the cellar of a castle in Aargau Kanton, Switzerland. Another subterranean occurrence was discovered by Tvrtkovic and Baltic (1996), where the remains of 16 N. lasiopterus were found in a cave on the island of Mljet, Croatia. N. lasiopterus is known from nine locations in Hungary (Vasarhelyi 1964, Topal 1959, 1976, Dobrosi 1993, Gombkoto et al. 1996, Czajlik and Harmos 1997, Cser kesz 1998, Matis et al. 2003), but no roosts have been reported. However, one partly destroyed corpse of N. lasiopterus was found in an attic in Hungary (Topal 1976), but this might have been captured and transported postmortem to the building by Tyto alba. One of the Hungarian localities of N. lasiopterus is a significant place of occurrence, which gives the opportunity to observe the species regularly. In 2004, a radio telemetry programme was initiated with the main aim of finding the roosts of N. lasiopterus and ensuring their conservation. This paper reports the first results concerning the roosting behaviour of the species.