Fróðskaparrit - 01.01.1993, Side 81

BATS IN THE FAROE ISLANDS
Fig. 3. og 4. Nathusius’s pipistrelle, Pipistrellus nathusii. Photo: Jiirgen Gebhard, Basel.
Mynd 3. og 4. Trøllflogmýs, Pipistrellus nathusii. Photo: Jiirgen Gebhard, Basel.
greater distances and can be separated into
stationary species and long distance fliers -
migrators (Strelkov, 1969). It seems to be
mainly the northernmost parts of the mi-
grating species populations that undertake
actual, regular and unidirectional migra-
tions to more favourable hibernation sites
further south. But the capability of long and
multidirectional movements remain pre-
served in other populations of those species
(Gaisler, 1979). Gaisler and Hanak (1969)
also introduced an intermediate category,
known as vagrant, of species that sometim-
es fly shorter distances (up to 400 km) be-
tween summer roosts and hibemation sites.
In general, the quantitative basis for classi-
fication is more meagre for bats than for
birds, but the amount of information is in-
creasing. Five to six species are believed to
be migratory.
Leisler’s bat, Nyctalus leisleri: On the
Continent, the northem border of distribu-
tion mns through the northern part of
middle Europe (Stebbings, 1988). In the
west, Leisler’s bat occurs in the Nether-
lands (Lina, 1990a), Belgium (one record),
central and southem parts of France, but
not in NW France (Stebbings, 1988) and it
is widely distributed in Spain and Portugal
(Palmeirim, 1990; Ibanez et al., 1992). It
also occurs in the southern half of England
and in the whole of Ireland where it is more
common than elsewhere (Stebbings, 1988;
Racey, 1991). It is the only bat species that
occurs on the Azores and it is also found on
Madeira. Closer to the Faroe Islands a
vagrant Leisler’s bat was found in Shetland
in 1968 (Corbet, 1970).
It is considered a migratory species
(Strelkov, 1969; Racey, 1991) and it is cer-
tainly capable of flying long distances.
Longest flights recorded are 418 km (Krza-
nowski, 1960), and 810 km (Aellen, 1983-
84) and Aellen (1962) caught 25 apparently
migrating individuals in Switzerland.
Nathusius’s pipistrelle, Pipistrellus nat-
husii: On the continent, the northern distri-
bution limit runs along the coasts of France,
Belgium, the Netherlands, through NW
Germany (Stebbings, 1988) and Denmark