"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
wim.vader@tmu.uit.no"
11-18th May 2013 in Tromso, can't what it's like Dec-Feb!
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