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changes in bird fauna at 70*N

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Subject: changes in bird fauna at 70*N
From: "Wim Vader" <>
Date: Sun, 11 Nov 2001 13:27:35 +0100

                        CHANGES IN BIRD FAUNA AT TROMSØ, N.NORWAY (69*50'N)


Tromsø, where I have lived and worked since 1973 (with several longer
visits in the decade before that) is situated in N.Norway, at a latitude
that would only be snow, ice and bleak tundra if we had not had reaped the
benefit of the warm North Atlantic Current, that bathes the coasts of
N.Norway and penetrates as far as the west and north coast of Svalbard
(Spitsbergen), ten degrees latitude north of here. Because of this
influence, we have a moderate Atlantic climate, birch forest, open water at
sea and on the coast year round. We also have less cold, but more humid
winters than more inland climates, and this tendency seems to have become
even stronger in the later years: "more weather of all sorts".

This week it has been snow! Since I last wrote to you, we have had snow on
most days and even the next outbreak of milder Atlantic air, yesterday and
today, was just not mild enough to do much else than whip up the winds and
replace the snow with hail and sleet, while temperatures hover just above
freezing. They will sink again from tonight, with more northerlies and more
snow to come. I see fewer thrushes around now, although the Rowans are
still bulging with berries, but now and then a large flock sweeps in and
through, so they are still around, as are the Waxwings and the scattered
Great Spotted Woodpeckers. (One lady phoned and told she had seen a very
strange thrush, and she probably had too; but identifying vagrants by phone
is not easy, and her description never could be fit to any bird in the book).

The weather is not really conducive to too much outdoors activities (My
skiing days being over), and instead I have been musing about the changes
in the local bird fauna in the 30-odd years I have followed the picture
here. They have, in fact, been quite many!!

Some are the usual changes in a growing town. When I arrived, Tromsø had 40
000 inhabitants, while now we have passed 60 000, by our standards a
sizeable town, and e.g. in my neighbourhood, at Sorgenfri near the sound,
there have been built several hundreds of houses and apartments the last
few years. As a result several bird species that still were quite common
nesters and winterers around here during my first years, are hardly ever
seen here anymore. I used to see Willow Grouse both around Tromsø Museum
and even in my garden now and then; the last one is probably at least 15
years ago now! Snipe winnowed and nested on the open area adjacent to the
Folkeparken (now radio and TV studio and music school); both they and the
redshanks have disappeared from this area, only the Oystercatchers have
persisted and they now nest on the flat roof of the TV house! In
Folkeparken Bluethroats sang, Sedge Warblers occurred in the more bushy
areas, and a Woodcock roded every spring in a course that brought it
straight over my house. Virtually all those have disappeared now,  although
strangely enough the Woodcock is still hanging on, in spite of the fact
that half Tromsø airs their dogs in Folkeparken, and often, against
regulations, let them run loose. Some other birds are strangely unaffected:
White-tailed Sea Eagles are still common in and around town in winter, and
several pairs of Red-throated Loons nest in the 'town pond', Prestvannet,
where all the burghers go to feed the ducks on Sunday.

But these are not the sort of changes I have in mind; these are just local
impoverishments because of too many people, dogs, cats and traffic, and all
these birds are still easily seen as soon as one gets to suitable places
out of town, usually even on the less built-up northern half of the island
of Tromsøya. A few other birds seem to have genuinely fared less well in
this period. Yellowhammers used to be regular spring visitors in town, and
Skylarks nested on the airport and at some other suitable localities, while
a few pairs of Temminck's Stints also nested at the airport and often could
be seen displaying from the boundary fence. These species are  gone or at
least definitely less common in the area now; this may be partly the result
of the destroying of the most suitable areas because of the extensions to
the airport and the traffic around (This also took a colony of Sand Martins
(Bank Swallows), that had nested there as long as I can remember), while
the larks and buntings probably suffer from the changing practices in
agriculture and the steadily diminishing number of working farms in the area.

When I first visited Tromsø on my honeymoon in 1965, and when I  moved to
Tromsø in 1973, there were a few species that then were quickly spreading
across N.Norway, and which I therefore was asked to keep an eye with. These
were the House Sparrow, that profited no doubt from the proliferation of
roads in the area, and the Great Tit and Pied Flycatcher, that spread
quickly in the wake of the new habit of putting out nest boxes for the
birds and feeding them in winter. All three species were already
well-established in town, when I moved there, although the nesting patern
of House Sparrows has remained extremely patchy: Although there are two
stable colonies some 100 yards down the road from my home, I have had
sparrows in my own garden only a few times during these 30 years---they are
extremely resident.

Another new bird species reached Tromsø in the late 60's (1969), at the end
of its marvelous march across Europe (which it now replicates across the
US), and that was the Collared Dove. As this is also basically a resident,
Tromsø is in fact not at all a suitable place for this more southern
species. Additionally,  there are both Sparrowhawks, Goshawks and the
occasional Gyr Falcon here in winter, where feral pigeons, crows and magpie
are the normal prey of the larger raptors. Still, a few pairs (usually
apparently just one or two) have hung on in a specially leafy area near the
cemetery all these years, where they are under the special protection of an
old lady, who feeds them in winter; and they are still here!

Temporary changes also occur regularly, partly because we are now and then
at the receiving end of invasions of birds from the vast taiga area further
east. This winter there are Great Spotted Woodpeckers, Bohemian Waxwings
and a few Siberian Tits, while in other years we may have Pine Grosbeaks,
various owls, or even Siberian nuthatches and the white-speckled Siberian
Goshawks. These birds are nevertheless almost exclusively winter visitors,
so do not affect the nesting avifauna. But this is different for a few
other species that now and then also arrive in numbers from the east, and
then swell the low numbers of local breeders. This is probably the case
with Bullfinches, Long-tailed Tits and Goldcrests in some years,  maybe
also Siskins, and this may well be a major reason for the large
oscillations in the numbers of those bird species locally from year to
year. And for two other species this is still more self-evident, as they
normally do not nest here near the coast at all, but have lingered and
nested in Folkeparken for several years after large winter invasions. These
are the Coal Tit and the Crossbill, both present for a few years as a
nesting bird in Folkeparken, but now gone again from there.

But the most interesting changes of all are maybe those birds that 'sneak
in' slowly', with gradually more observations in the town area, until one
suddenly comes to the conclusion that they have come to stay. An early
example of this was the Greenfinch, that cheerful bully of the garden
feeders that now is one of the most common winter birds in town. When I
arrived in 1973 there were no Greenfinches in Tromsø at all, and the
official northern border of its distribution area was south on the island
of Senja, some 150km south. Then they were seen more and more often, and
stayed longer and longer in the autumn, and now they are in practice a
common resident all over town, --and also virtually all over northern
Norway--, and maybe the most common bird on my feeders in autumn and
spring, usually also still present in winter. The reason for this
range-extension is unclear; it is of course tempting to call out: 'Global
warming', and milder winters may well have played a role, but I suspect
that also the growing up of the many coniferous plantations and hedges in
and around town may have had a favourable effect, furnishing as they do
both good nesting areas and protection and shelter from the elements in winter.

In Folkeparken, the mixed remnant birch forest and spruce plantation,
around Tromsø Museum and between the museum and my home, there have also
been changes the last summers. Garden Warblers, earlier always to be relied
on to be present in the morning chorus, although never many, have gradually
become less and less reliable here, and I blame mostly the compulsive
neatness of the park people, in combination with all the loose dogs, for
that. But we have got new voices too; European Robins, until recently
typically a bird of the inland pine forests here in Troms, have discovered
the place and last summer there were at least 3 or 4 of these fine singers
with their crystal flutes, and I heard them also scolding regularly and saw
the speckled young later in the season. And also the sonorous voice of the
Wood Pigeon is now heard in Folkeparken each spring, although nesting is
not yet proven here. Last spring I came across a flock of some forty
pigeons in Balsfjorden, some 40 km souith of Tromsø, and I have no doubt
that they too have come to stay.

On the coasts of our island there is also a newcomer of the last ten years,
when the Grey Heron started nesting in a small coniferous wood. And
now  these stately herons are a feature of the  local intertidal both
summer and winter (they winter locally!), and last winter I saw a flock of
18. These herons are sea-fishermen here mostly, but in summer one can also
meet some along the many small lakes, competing with the loons and mergansers.

Finally I want to mention two further newcomers, that have not yet really
made it into Tromsø town, but are clearly on their way. These are the
feisty Blue Tit and the colourful but crafty European Jay. I have these
last two years got many telephones from people in the country south of
here, telling that they have seen these new birds around their homes or
even on their feeders, and both are clearly slowly extending their area of
distribution northwards and toward i.a. Tromsø. Both are resident bird
species, and therefore the march north is slow, and the Blue Tit, that
relies heavily on nest boxes, will also suffer severe competition from
Great Tits and Pied Flycatchers, but I feel sure they are going to make it,
and they will constitute a welcome addition to our bird fauna. I have not
yet seen the Jays myself, but I have come across Blue Tits quite regularly
on my spring excursion along the Balsfjorden.

I am unsure, in how far such a story as this is of any interest at all for
people in different parts of the world for whom all these bird species are
merely names, but I felt the urge to sit down and sort out all these
gradual changes over a longer period; it is the advantage of adverse
weather! And there is always the delete button!

                                                                Wim Vader, 
Tromsø Museum
                                                                9037 Tromsø, 
Norway
                                                                

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