Fróðskaparrit - 01.01.2009, Síða 189

RINGMERKINGAR AV FØROYSKUM GRÁSPURVUM ÁRINI 1963-2007
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the house sparrow reluctant crossing open
water or mountain barriers separating the
Faroese settlements (Bengtson et al„ 2004).
Therefore, newcolonization mainly occurred
along the coast and open areas with sources
from the neighbouring settlements. Thus, it
took long time to spread all over the islands.
During the years 1940 to 1962, 27% of the
settlements had been colonised. In 1972 this
had attained to 35%, in 1988, 65% and in
2002, 80% of the 118 Faroese settlements
were more or less colonised by the house
sparrow (Bengtson et al„ 2004).
Indeed, the low dispersal between vil-
lages observed in the Faroese ringing stud-
ies, the results are in accordance with earlier
findings for this species, both world-wide
(Summers-Smith, 1988; Wernham et al„
2002; Bønløkke et al„ 2006; Bakken et al„
2009) and in the Faroe Islands (Jensen and
Kampp, 1997). Besides low, or hardly any mi-
gration between villages, high fidelity to the
area for the house sparrow has also been
demonstrated in other studies. A review of
Danish ringing studies during the 19th cen-
tury showed, that of 873 recoveries, 84%
were within 1 km of the ringed site and 98 %
within 10 km (Bønløkkeeta/., 2006). Investi-
gations of the Faroese house sparrow show
similar results. In a small-scale study, where
112 house sparrows were colour banded at
seven diflferent locations in Tórshavn, most
recoveries were sighted within 500 m (max.
ca. 1600 m) of the ringing site (Eliasen and
Jacobsen, 2002).
Generally, the dispersal of the house
sparrows depends on the birds age, being
highest for the juveniles (Summers-Smith
1988). Once the house sparrow has bred, it
usually remains faithful to the breeding area
and, according Summers-Smith (1988), they
rarely move more than two kilometres to
find food. This statement is also in accor-
dance with results found elsewhere. Based
on nearly 6,000 recoveries, Paradis et al.
(1998) calculated the mean natal dispersal
to be 1.7 km and breading dispersal 1.9 km in
different places in the UK. In Norway, the av-
erage distance between ringing and recovery
sites was a little longer: 4 km for those ringed
as fully fledged and 12 km for those ringed
as nestlings (Bakken et al„ 2009).
Figure 3. Cause of death for
house sparrows ringed in the
Faroe Islands (n= 98).
3% Other known causes