Fróðskaparrit - 01.01.2004, Side 257

HVUSSU MÚSABRÓÐIR (TROGLODYTES TROGLODYTES) YVIRLIVIR,
SPJAÐIR SEG OG HVUSSU STAÐBUNDIN HANN ER í FØROYUM
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more likely to disperse. Since the wren is
strongly territorial (also in autumn and win-
ter) and the quality of the Faroese breeding
sites assumedly varies, there might be dif-
ferences in site fídelty between the sexes
and sites. This supposition regarding differ-
ences related to habitat quality was based
on suggestions that because of low levels
of food resources the island wrens are mo-
nogamous, in contrast to their British and
Continental counterparts where polygamy
is common (Armstrong, 1955; Armstrong
and Whitehouse, 1977).
Study areas, material and inethods
The wren breeds commonly all over the
Faroes, both in the infields (i.e. the inhab-
ited areas and their surrounding managed
land) and outfields, the latter including high
coastal cliffs as well as inland cliffs and ra-
vines (Bengtson, 2001). Wrens were ringed
during the breeding season (June-July) at 7
sites on 6 islands from Mykines in the west
to Fugloy in the east (see Bengtson, 2001:
Fig. 1):
(i) On Mykines, in an area that includes the
settlement and parts of the puffinries im-
mediately wesl of it. This area supports
a dense population of wren and a rich
insect life.
(ii) On Koltur, around the two nowadays un-
inhabited farms each with one breeding
pair.
(iii) At Tjornuvík at the northern end of
Streymoy; with 2-5 pairs breeding in
the infield and adjacent outfield areas.
A secluded and geographically isolated
site.
(iv) Immediately south of Haldarsvík, just
south of Tjornuvík on Streymoy. A rath-
er open, exposed outfield area with a
relatively low density of breeding wrens
and a moderately rich vegetation con-
fined to cliffs and ravines.
(v) At Gjógv at the northern end of Eystur-
oy; a sntall settlement with a few breed-
ing pairs and one or two of them in and
around the secluded harbour where there
are cliffs with luxurious vegetation.
(vi) On Kunoy in the settlement (incl. the
plantalion) with the same name. Several
pairs breed among the buildings and on
the outskirts of the settlement.
(vii) Att Kirkja on Fugloy in an area includ-
ing the infield and the outfields north-
west thereof along the coast to Fótur
where there is a number of breeding
pairs, one in each gully. The infield part
has a fairly rich vegetation, contrary to
the outfield parts.
Ranking these study areas subjectively (to
some extent supported by data on inver-
tebrates from pitfall traps and sticky traps
for insects) with respect to their suitabil-
ity (quality) for breeding wrens leads to
the following order: Mykines stands out
as being the most suitable followed by
Gjógv, Kunoy, Koltur, Tjornuvík, Fugloy,
and Haldarsvík. In at least one respect this
ranking may be questioned as it does not
take into consideration the presence of feral
cats, which occur in many settlements and
undoubtedly kill a considerable number of
wrens, particularly nedglings.
Altogether 134 wrens were individually
ringed with numbered rings and/or col-
oured plastic rings in the study areas (Tab.