Fróðskaparrit - 01.01.2009, Síða 185

RINGMERKINGAR AV FØROYSKUM GRÁSPURVUM ÁRINI 1963-2007
183
Introduction
The Faroe Islands were colonized by the
house sparrow (Passer domesticus) in the late
1930s (Petersen, 1949; Jensen and Kampp,
1997; Bengtson et al., 2004). Before that, it
was considered a rare vagrant and only
recorded once (Andersen, 1901; Salomon-
sen, 1934). Today it occurs abundantly all
over the Faroes and is confined to breed in
most build-up areas (Bengtson et a\„ 2004).
Even though the house sparrow belongs to
the most common sedentary birds in the
Faroes, knowledge on its general biology on
the islands is sparse. Jensen and Kampp
(1997) measured the wingspan of house
sparrows from different Faroese villages.
They found a considerable geographic varia-
tion, which they explained by the existence
of local subpopulations, separated from each
others. Bengtson et al. (2004) described the
history of colonisation by the house sparrow
and its current status in the Faroes Island.
Censuses all potential sparrow-habitats, they
estimated the Faroese house sparrow popu-
lation to be in the order of 2,600 breeding
pairs. Additionally, they found that 80% of
the 118 settlements in the Faroes Islands
were more or less regularly occupied by the
house sparrow.
In this paper, we report the results from
all ringingstudies of the Faroese house spar-
row, which have been carried out since 1963.
These results give the basis for description of
the movements and life-span of the Faroese
house sparrow.
Material and methods
The present paper is based on results from
ringing studies of Faroese house sparrows.
Most of the data have been provided by the
Copenhagen Bird RingingCentre, Zoological
Museum, which has been the ringing au-
thority of all studies. The Copenhagen Bird
Ringing Centre's guideline for ringing and re-
covery of birds is available on:
http://www.zmuc.dk/VerWeb/ringing/del1.
htm.
Adults and juveniles ringed were caught
by mist net, Bow net, funnel trap or a Hel-
goland trap, whereas the pulli were ringed in
nestling boxes during their first week of life.
The age was determined on a scale from 1-4:
1 = Pullus i.e. nestling or chick. 2= Full-grown,
age otherwise unknown. 3= First calendar
year 4= Older than firs calendar year. The
life-span was defined as the time-lapse be-
tween the date of ringing and the date when
recovered as dead. Only birds ringed as
nestlings or juveniles in their first autumn
were used for calculation (see Bønløkke et
al„ 2006; Bakken et al„ 2009).
To get the best possible quality of the
date and to be sure that no results have been
forgotten or misreported, we have, when
possible, been in personal contact with the
persons responsible for the different ringing
studies.