Fróðskaparrit - 01.01.2009, Blaðsíða 95

í EITT ÁR VÓRÐU REIÐURSTAÐIR HJÁ HAVHESTI (FULMARUS GLACIALIS) í FØROYUM
EYGLEIDDIR VIÐ VAKMYNDATÓLI
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when the fulmars are absent for periods of
time. The number of fulmars present at any
time is influenced by several factors such as
wind speed and direction, time of day, and
state of reproduction (MacDonald, 1980;
Hatch, 1989; Ojowski et al„ 2001). We moni-
tored attendance by employing surveillance
cameras that were operated continuously at
10 nest-sites; hence allowing us to study pre-
sumed individual pairs (regrettably few birds
could be marked and individually identified)
and to explore topics such as (i) post-breed-
ing absence and date of first landing, (ii) sea-
sonal pattern in attendance, (iii) timing and
frequency of copulations, and (iv) occur-
rence and length of a pre-laying exodus. In
addition we also obtained pertinent infor-
mation on numbers of breeding pairs and
breeding success as well as some observa-
tions on site tenacity, and mate fidelity.
Material and methods
Observation
The study was carried out close to an aban-
doned quarry at Sund (N62°2'59 W6°50'46)
north of Tórshavn on Streymoy, which is the
largest island in the Faroes. The colony itself
ls located on low cliffs on the southern side
°f the fiord Kaldbaksfjørður. The site was
choosen because of its relative accessibility,
and that preliminary surveys had indicated
that it hosted about 30-40 pairs of fulmars.
The colony was surveyed by means of binoc-
flars and a telescope (32x77) on a tripod
from a distance of 650 m at a point on the
opposite side of the fiord. Each year in June
(2006 in April) fulmars sitting on the cliffs
and ledges were plotted on a map of the
colony (several times a day for 2-9 days each
ycar; Table 2) allowing us to assess the num-
berand position of potential nest-sites. Dur-
ing the course of the study (2004-2007) a
total of 40 different potential nest-sites were
identified and each was given a permanent
number, and 10 were selected (mainly on the
basis of their accessibility) for closer studies,
using surveillance cameras (Sony LL 20); 8 of
which later contained egg or chick on at
least one occasion during the study. Each
camera was fixed to an adjustable foot that
was fastened directly on to a rock using
Epoxy glue. The cameras were connected to
the field computer via cables running
through water pipes from the field to the
computer shed, which was situated about 20
m from the nearest camera. With the aid of
infrared LEDs the cameras were able to
record all activites at the nests 24 hours a
day, but since they were motion sensitive, it
was necessary to regularly empty the field
computer for various „junk data"; mainly
movements of vegetation due to wind. The
surveillance cameras were operated from
August 2005 until July 2007 and they recor-
ded, with some unfortunate gaps, the activ-
ity at 8 and 5 nests, respectively (Table 1).
Breeding success was assessed when in
2004, 2005, and 2007 all potential nest-sites
(nos 1-40) were examined in search of breed-
ing evidence (i.e. eggs and/or chicks), where-
as in 2006, in connection with other studies
taking place, only sites nos 1-15 were
checked.
Marking and handling ofbirds
Several activities during the field work may
potentially have influenced the subsequent
behaviour of the birds. In 2004 fulmars were
caught by fleyg, the traditional method of
catching fulmars and other seabirds in the