During the last months I have again got several queries as to which birds that
can be found here during the dark and cold winters at 70*N. I wrote about that
five years ago, but as the turnover on these lsist is quite large I may maybe
be forgiven to send the same piece out once more, rather than answer all the
individual queries. So here goes!
BIRDS WINTERING IN TROMSØ, N. NORWAY
I originally wrote this piecefive years ago at 65*S, as far away from Tromsø as
I have ever been probably, on a ship in the open Weddell Sea in the Antarctic.
Our ship, the Polarstern, lies on station near a large table iceberg, floating
over a sea just here 4780m deep (I know, as we are sampling the bottom fauna
here), and around the iceberg fly a couple of terns, Arctic Terns, possibly on
their way to Tromsø to nest there. This is about the longest migration route of
any bird known (although some southern shearwaters fly comparable distances
from their southern nesting areas to winter in the northern Pacific, and South
Polar Skuas have also been observed quite regularly in both the northern
Atlantic and Pacific). Still, all the other birds seen here never make it even
as far north as the equator, so the Arctic tern is definitely a special case.
It made me think, though, about the great variation in migration patterns among
the birds that are common in Tromsø, and as I have time on my hands
here---deep-sea collecting is often a slow business--- I thought it might be of
some interest to give an impression of this variation, even though I can not
check up all the details down here.
Not all birds in Tromsø migrate, in fact, in spite of our far northern locality
and the very prolonged, although not overly severe, winter. Our crows, ravens
and magpies are sedentary, and so are the various grouse: Willow Grouse,
Ptarmigan, Black Grouse and Capercaillie. Among the small birds, the House
Sparrows stay put, and so do most of the tits, the Creeper, and the Goldcrest,
as well as the Bullfinch and latterly also the Greenfinches of our feeders.
Also a few raptors spend the winter in the far north, local examples are the
White-tailed Sea Eagle, the Sparrow hawk and the Gyrfalcon, as well as some
forest owls. On the coast the local Common Eiders stay year round, and so do
the newcomers Grey Heron, while the Mallards of the island content themselves
with moving from their nesting lake on top of the island of Tromsøya to the
coasts of the sounds around the island, where the water never freezes over.Also
our Red-breasted Mergansers are with us summer and winter.
For some other species the situation is more complicated than it seems at first
sight; we do have them on our island both summer and winter, but they may well
not be the same individuals. Good examples of this are the Herring and Great
Black-backed Gulls; they are common year round in Tromsø, but ringing results
seem to indicate that the majority of our nesting birds migrate to the
countries around the North Sea, while they are replaced in Tromsø in winter by
birds that nest further north and east, e.g. in North Russia. Also our eider
flocks are augmented in winter by northern birds, i. a. those that nest on
Spitsbergen, easily recognized by a somewhat different bill colour. Similarly,
the Kittiwakes on the coast in winter, and the Guillemots (Murres) in the outer
fjords may well be primarily far northern birds, and not our own nesters, in
fact we have had returns also from immature British guillemots from winter
Tromsø
.
We know that for sure for a few other species that have been better studied:
Purple Sandpipers nest in the hills around Tromsø, although sparingly, and they
are, as the only shorebirds left in that season, also common in winter on our
stony coasts. But these are exclusively birds from northern Russia and the
Arctic areas, and our Purple Sandpipers spend the winter further south in
Europe.
(Similarly, Snow Buntings are common nesting birds of stony slopes in the
surrounding hills, where their cheerful presence and song greatly enliven that
often a bit depressing landscape. They are also well-loved in town as
harbingers of spring, and in late April-early May may occur in large numbers in
town and on partly snow free areas along the coast; they also come to feeders
in the gardens at that time. But these are not at all our nesters; these hordes
all belong to the E. Greenland population of Snow Buntings! These have a
complicated migration pattern, and apparently winter somewhere in Russia ---
they then move to the coasts of N. Norway where they stay for a while and
fatten up before the long and arduous oceanic crossing to Greenland. Meanwhile
our local Snow Buntings sneak in more or less unnoticed on their nesting
territories, and we see them rarely in town.
As far north as Tromsø may seem to be for most of you, we still have a number
of wintering birds that consider our winter climate an improvement to that of
their nesting areas, and who winter regularly in the Tromsø area. These are
almost exclusively coastal or sea birds, at least in winter. These hail mostly
either from the Arctic islands: the Svalbard archipelago, Frans Josef Land and
Novaya Zemlya, or from the bleak northern coastal areas of Russia. A few, like
the two scoters and the Long-tailed Ducks, all common winter birds on the
fjords, come partly from closer by, the now frozen freshwater lakes of N.
Scandinavia. But the King Eiders from Svalbard and the White-billed Divers from
N. Russia (Yellow-billed Loons, if you prefer; it is still the same bird, with
a bill neither truly yellow or white), the most famous of our wintering birds,
do not nest in Norway at all, and the same goes for the Glaucous and Iceland
Gulls that also are regular, though never very common winter visitors
here---they are much more common on the Finnmark coasts, where also Steller's
Eiders winter in large numbers.
There are also more local movements which result in wintering birds in Tromsø.
For some reason Cormorants Phalacrocorax c. carbo do not nest in the immediate
area around Tromsø, although they have colonies both north and south of us. But
in winter they migrate to Tromsø harbour in considerable numbers, and some old
wrecks and derelict piers are literally festooned with them in the winter half
year. Auks of several sorts, mainly Razorbills and Little Auks (Dovekies, who
nest on Svalbard) stay in winter normally mostly on the open coast, but come
near town under certain circumstances (large shoals of pelagic fish for the
Razorbills and occasionally Puffins, mostly adverse weather for the Little
Auks). As reported before, we can get wracks of Little Auks when strong winds
blow the birds ashore and often far inland.
As inland Troms is so much colder than the coastal areas where we live, there
may be also be movements coastwards in winter. These are not regular, however,
but have more the character of infrequent influxes. Underlying causes are often
as much scarcity of the right food as directly the cold itself. In years of
very rich crops of Rowanberry (Mountain Ash, Sorbus aucuparia) not only our
nesting thrushes (Fieldfares and Redwings) stay much longer in autumn, but we
may also have invasions of Bohemian Waxwings and, less often, Pine Grosbeaks
from the taiga forest of inland northeastern Scandinavia, Finland and N.
Russia. From the same regions in many winters come influxes of great Spotted
Woodpeckers, Crossbills and forest owls, chiefly Hawk Owls; more rarely we
have had Siberian Goshawks and ditto Nuthatches, while the invasions of
Siberian Nutcrackers usually go further south into S. Scandinavia and W. Europe.
Some winters we also have large numbers of birds that are normally uncommon in
the area, such as Long-tailed Tits, Coal Tits, Goldcrests, and Redpolls, but
such top years concern the entire area, and seem more to be a strong increase
in numbers than a migration. The normal resident birds of the inland usually
stay put, although a few Tree Creepers may turn up on the island in winter;
Siberian Tits, for example, I see not more often on Tromsøya than maybe once
every five years, and Siberian Jays and Three-toed Woodpeckers I have as yet
never met here at all.
These are the birds that make up the wintering population at 69*50*N.
Wim Vader, Tromsø Museum
9037 Tromsø, Norway
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