Fróðskaparrit - 01.01.1983, Síða 79

82
THE AUTUMN MIGRATION AT AKRABERG,...
About 15.000 migrating Kittiwakes were
observed, the maximum being about 2.000
in one hour. The migrating movements of
the Kittiwake were similar to those of the
Fulmar. The large movements of Fulmar and
Kittiwake took place early in the day in
high southerly and southwesterly winds. Their
movements are interpreted as mainly foraging
movements, during which onshore winds
carry the birds particulary close to the coast.
The presence of at least partly local popula-
tions applies to both species.
It is difficult to ascertain the extent of true
migration of Fulmar and Kittiwake, but an
increasing number of »double dark morph«
Fulmars indicates that also foreign popu-
lations were present in the waters.
About 500 Gannets were seen, the maxi-
mum being 50 per hour. Without exception,
migration culminated during the earliest
hours of the day. Both along the eastern and
the southwestern coast, birds were flying to-
wards the south and the southeast. It is likely
that, besides foraging movements, many
birds were really migrating. At the end of the
period of observation, the number of Gannets
decreased abruptly, as the last 3 days had no
records at all. This surely shows that mi-
gration from the area has finished before the
middle of October. Evidently, the younger
birds migrate first as 99 % of all the observed
Gannets were adults, and no birds were
younger than 3rd C. (in all, four birds were
4th C. and one 3rd C.). In comparison with
the observations at Blávandshuk (Meltofte &
Overlund 1974), you will find that the migra-
tion at Akraberg has finished 2 or 3 weeks
before the migration in the southern part of
the North Sea and at both places the younger
birds migrate first.
All European species of Skuas were ob-
served, but in small numbers (table 4). Typi-
cally, the Skuas were seen on days of high
onshore winds, as was the case at Blávands-
huk (Meltofte 1979).
Apart from most of the Great Skuas Ster-
corarius skua, all the other Skuas were ob-
served flying actively towards the south,
evidently migrating.
Among other sea birds Sooty Shearwater
Puffinus griseus is worth mentioning. Five
days had a record of this species with the only
large occurrence of 184 birds in 31 2 * * 5/2 hours
on Oct. lst (table 4). All birds followed the
Table 4.
The observered number of Shearwaters, Skuas, Merlins and Geese.
September October
Species Date 17 18 19 20 21 22 23 24 27 28 29 30 1 2 4 5 6 7 8 9 10
Sooty Shearwater
Pomarine Skua
Arctic Skua
Pom./Arc. Skua
Long-tailed Skua
Great Skua
Merlin
Pink-footed Goose
Greylag Goose
Barnacle Goose
Goose sp.
1 11 184
2 1
11 7 4 1
2 1
1
1 11 2
2 1 1 2 12 2 11
50 41 16 46
8
5 7 7
1 3
1
1 1 1
15 8
5
7