Suomen Luonto
English summaries 11/2000

The forest’s gimlet eye
By Juha Valste
Pages 4–11

With a size only equal to that of a starling, the pygmy owl is Europe’s smallest owl. Previously it was thought that there were 200-300 pygmy owl pairs in Finland but we now know that there are at least 10,000 of them.

The pygmy owl can easily be distinguished from Tengmalm’s owl because it is smaller and has a cruel look about it. In daylight a Tengmalm’s owl looks as though it has just had a fright - the yellow eyes of the pygmy owl have the forest’s most piercing gaze. These small owls inhabit Finland wherever there is boreal coniferous forest, nesting in old woodpeckers’ holes (strictly speaking, cavities) and willingly, when available, in nest boxes. In winter, the pygmy owl can be seen around the bird table, where it can feed on small birds just as easily as great tits or bullfinches feed on seeds.

Pygmy owls prey on voles, mice, shrews and small birds. Occasionally, one may nab a thrush, blackbird or great spotted woodpecker, birds that are larger than the owl itself. The owls store food in the form of small mammals and birds in woodpecker holes and nest boxes in autumn and early winter. Should it become hungry in winter, the owl will visit its larder for food.

“Thur’s gold in them thar hills”
By Juho Rahkonen
Pages 18-21

The River Lemmenjoki flows through Finland’s largest national park, Lemmenjoki National Park, in what Finns call Inari Lapland. This park extends over 2,900 square kilometres. It encloses fells that soar above the treeline, with fell, or mountain, birch clothing their lower slopes. Scots pine forests grow along the rivers and in the valleys, the largest trees being over 600 years old. The autumn russet is exceptionally spectacular in the Lemmenjoki valleys, thanks to the extensive fell birch forests and abundance of dwarf shrubs. In many years, snow begins to fall, however, in September or October.

The Lemmenjoki is well known for the gold rush taking place there after the Second World War, and for its prospectors who, even today, pan for gold along its tributaries and streams. There are still a handful of professional gold diggers sharing the area with a few dozen semi-professionals and thousands of tourists each year, who arrive here believing they will “strike it rich” and who at least make an effort to realise their dreams.

Vuotos Reservoir would destroy eastern Lapland’s tourism aspirations
By Tapani Niemi, photos by Veikko Vasama
Pages 22-26

Tourists coming to Lapland seek peace and quiet, peace of mind, experiences and adventures in the wilds, and beautiful scenery. Tourism would create permanent jobs in eastern Lapland and help to keep the villages inhabited. If the Vuotos Reservoir is ever built, these dreams of opening up tourism in the area will be destroyed.

A conflict has been raging over the proposed reservoir for over 20 years. Most of the area’s inhabitants have sold their land to the power utility, but there are many who obstinately continue to refuse to move. The reservoir would flood mires which have been shown to be important bird habitats under the EU’s criteria. Several bird species nest there which are the target of special conservation measures in Europe. Moreover, the scenery and the residents are themselves worthy of preservation.

Buprestid beetles arrive after a fire
By Ilpo Mannerkoski, photos by Jouko Veikkolainen
Pages 28-31

There are only around 30 species of buprestids in Finland, whereas some 15,000 are known worldwide. Many species are beautifully coloured and a large number have a metallic colouration. In Finland, however, buprestids tend to be more sombrely dressed than their relatives living in hot countries.

Buprestids favour dry, warm areas where the forest cover is frequently burned. Among the most familiar species of burnt areas immediately after a fire are Melanophila acuminata and Phaenops cyanea. These are able to detect a burned area through their antennae, which are sensitive to chemicals formed by the combustion of wood. Equipped with special organs for the job, the beetles use infrared radiation to home in on an area.

In Finland, the best area for buprestids of this kind is the army firing range at Hankonniemi, where small scale fires frequently flare up. Here species like the rare Buprestis novemmaculata, and the commoner B. octoguttata, have been observed. Some buprestids have taken to living in houses as well. These include Buprestis haemorrhoidalis (heaven knows where it got its name from!) and B.rustica.

Buprestids are Finland’s most seriously declining beetles. Changes in forestry practices, the reduction in the number of forest fires, and climate change have all adversely affected them. Of our 30 species, one, Chalcophora mariana, has become extinct in this country, while 11 more are endangered and two are vulnerable.

Awaiting us in a hundred year’s time
By Antti Halkka
Pages 32-36

Finnish researcher Markku Rummukainen is spearheading the six-year Sweclim project at Norrköping, Sweden. The project aims to elucidate the impact of the greenhouse effect on climate. Despite its name, the project is a joint Nordic one featuring researchers from different countries.

For the first time it has been possible, through Sweclim, to integrate local Fennoscandian factors into the large calculations affecting the entire globe. In this way, the effect of, for instance, the Baltic Sea and the mountain chain lying between Norway and Sweden can be evaluated. As a basis for these calculations, Sweclim has actually used the global models developed by Britain’s Hadley Centre and Germany’s Max Planck meteorological institute.

The results have been alarming. Northern Europe is warming much faster than the world on average. In addition to the actual warming, torrential autumn rains are expected, in addition to warm, wet winters and a much earlier spring than previously. Finland’s mean winter temperature will rise by over five degrees Celsius, and the mean summer temperature by three degrees. The climate of southern Finland will come to resemble that of present-day Denmark. Southern Finland’s winter snow cover will be similar to that of Poland, and conditions in Lapland equivalent to those of the Tampere region of Central Finland at the moment.

If these predictions come true, Finland’s ecosystems will rapidly change into the present-day north Central European type. However, the researchers hope that their forecasts will never actually come true. The predicted events will happen unless human society is able to prevent the greenhouse effect from accelerating.

”Peat frenzy” disturbs mire nesting birds
By Jorma Luhta
Pages 38-39

A large peat-fired power plant uses up all the available peat within a hundred kilometre radius. Mire and bog nesting birds ought to learn to avoid nesting in any suitable habitat within this area. A pair of peregrines attempted to nest on a mire being used for peat extraction purposes, but were obliged to forsake their nest and eggs due to constant disturbance. Protected mires have been artificially drained by open ditching and restrictions on their use have been lifted after the event, while peat-stained waters have been conducted off bogs into previously unpolluted wilderness areas. Peat really cannot be said to be an environmentally friendly fuel!

Heliconiids willingly expose themselves
By Tari Haahtela
Pages 44-47

Heliconiids are butterflies with long, narrow wings, long, thin bodies, long antennae and large eyes. There are some 70 species, inhabiting the southern states of North America, Central and South America and islands in the Caribbean. The greatest number of species are found in Brazil and Peru, in the Amazon basin.

Heliconiids are some of the most eye-catching neotropical insects. They have startling colours and tend to show themselves off. Few colours adorn their wings but these are extremely arresting. Their purpose is to warn predators of their owner’s toxicity.

The larvae of heliconiids eat the leaves of cyanide-containing Passiflora sp. vines. In so doing, they themselves become poisonous. Adult butterflies contain so much toxin that birds leave them well alone. Thanks to this freedom from predation, heliconiids do not appear to fear any other animals.

A combination of toxicity and bright colour patterns effectively protects these butterflies from potential predators, so much so that many other, perfectly palatable, species have come to copy the warning colours and patterns. This is called Batesian mimicry. However, heliconiids also copy each other, making them sometimes difficult to identify. An insect’s warning colouration can be even more effective, if one poisonous species mimics another - thus ensuring that there are even more similarly adorned, best-avoided individuals flying about in the forest. This kind of mimicry is known as Müllerian mimicry.

As adults, heliconiids live for rather a long time - even as much as nine or ten months - so that they consume pollen in addition to energy-providing flower nectar. They have excellent sight, relatively large brains, and good memories. Thanks to their longevity, these butterflies are able to learn to recognise their environment better than butterflies on average.

This skill, though, is of little use where forests are being destroyed - rainforest destruction is threatening a large proportion of heliconiid species.

Teksti: Leigh Plester