Fróðskaparrit - 01.07.2004, Blaðsíða 57

EITURKOPPAR (ARANEAE) í FØROYUM: EITT ENDURSKOÐAÐ YVIRLIT
OG EIN DAGFØRING AV ÚTBREIÐSLU INNANOYGGJA
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dispersal ability of species. When Brænde-
gaard (1928) completed his major treatise
on the spiders of the Faroe Islands, based
on collections made by Danish zoologists
in 1925-1926 and previously published in-
formation, he listed 43 species as having
been found in the islands. In dealing with
the spider fauna of Shetland in a zoogeo-
graphic context, Ashmole (1979) listed 59
(+1 ?) species in the Faroes. He based this
figure on previouly published information
(including Holm 1967) and an unpublished
list of species collected by Holm in 1966.
In summer 1978 (with some additional
fieldwork in 1979) a Swedish-Norwegian
team (including two of the present authors
viz. S.-A.B. and P.H.E.) made extensive
collections (112 localities), all over the
archipelago, with the primary aim of study-
ing the influence of Man on the species
composition of the terrestrial invertebrate
fauna of the Faroes (see Enckell et al.,
1987; Enckell, 1989). The spider material
was published by Bengtson and Hauge
(1979, see also 1981) and among the 49
species collected, 7 were reported new to
the Faroes. Holm (1980) published 15
species new to the islands and, also refer-
ring to those reported by Bengtson and
Hauge (1979), he put the total number of
spider species found in the Faroes at 66 (cf.
Discussion). Since then and until now only
three species new to the Faroes have been
reported (Hauge et al., 2002; Magnussen,
2003; Aakra and Olsen, 2003).
For the majority of species our knowl-
edge about their distribution in the islands
increased considerably as a result of the
fieldwork in 1978. During the subsequent
decades collecting (pitfall trapping) was
conducted in a number of places and for
different reasons. First, to re-investigate a
number of localities studied in 1978. Sec-
ond, to study seasonal and annual variation
by continuously trapping in logistically
convenient localities. Third, to study some
islands or particular sites in more detail,
viz. the small islands Koltur and Lítla Dí-
mun, Kunoy, and sites with abandoned set-
tlements or shielings on Kunoy and Borðoy
(see Enckell and Rundgren, 1988). This pa-
per reports on 13 species recorded for the
first time in the islands and numerous other
findings that contribute significantly to our
knowledge of the distribution of Faroese
spiders.
Areas, collecting, and material
The Faroes consist of 18 islands (Fig. 1)
ranging in size from 0.8 to 374 km2 (total
area 1,399 km2) and mountain peaks reach-
ing 882 m a.s.l. The climate is maritime
with mild winters and cool summers (4.1
and 11.1 °C in February and August, re-
spectively) with frequent strong winds and
varying but regular rainfall. Vegetation is
dominated by various types of grassland
(mostly grass heaths) and on higher
grounds sparse alpine vegetation (Fosaa,
2001). However, in association with the, al-
most invariably coastal, settlements there
are usually infields with lush grass mead-
ows and rich herbage that contrast with the
less rich grasslands and heaths that consti-
tute most of the outfield habitats.
Pitfall trapping provided effectively the
entire spider material. At each locality one
series consisting of 5 traps was employed,