Facts: Winners and losers among Sweden’s birds
About 250 bird species breed in Sweden. Inventories show that some of them have increased strongly in the last 20 years. This includes mallard duck, red gladiator, white-tailed eagle, pied piper, sandpiper, wren, spruce warbler, grebe and gray coot. In addition to these, among others whooper swan, greylag goose, great grebe, merganser, reed, crane, ring dove, greater woodpecker, robin, thorn warbler, kingbird, blue tit and whooper have increased in numbers.
Other species show a large decrease: puffin, eider, brushhane, barn swallow, house swallow, pine tit, greenfinch and ortolan sparrow. Also tufted whip, great sparrow, laughing gull, gray tern, tern, silver tern, bittern, birch thrush, green warbler, wood warbler, entita, starling and yellow sparrow have lost ground.
Many other species have been surprisingly stable for a long time, for example mallard, sparrow hawk, seagull, tern and blackbird.
Source: Swedish bird taxation
— The leaf warblers tend to disappear in warm southern locations. It must be remembered that it is essentially a northern species, and the probability is that it has become too warm in many places. It will perhaps be replaced by the warbler, which is undergoing strong expansion in Sweden, says Anders Wirdheim, ornithologist and responsible for the annual compilation of Sweden’s bird species, which is done under the auspices of Lund University and the Ornithological Association of Sweden.
The climate is just one of many factors that control which species decline and which increase. Anders Wirdheim points out that the biggest problem is the transformation of the agricultural landscape. Forestry is also a bigger threat than the climate – so far – but it is predicted that the effects of climate warming will become increasingly noticeable in the coming decades.
The songbird is Sweden’s most numerous bird species. It is also one of our best singers. But there are signs that it is declining due to global warming. Stock photography. Winners and losers
Some winners are already clear. In addition to the pine warbler, the wren, the sparrowhawk and the gray warbler have increased greatly in the last 20 years. In all cases, these are species that benefit from mild winters and/or a warmer and drier climate. In fact, the sturgeon is a characteristic species in the Mediterranean countries.
The losers are not as easy to identify. Most of Sweden’s seagulls have declined significantly, but there it is not particularly likely that the decline is climate-related.
– On the other hand, it is possible that the eider’s sharp decline has something to do with the climate. Danish studies have shown that the blue mussels that eiders live on do not put on as much fat as before due to rising temperatures. Perhaps the eider females have found it increasingly difficult to eat themselves before reproduction, says Wirdheim.
Steglitsen is one of the big winners in the Swedish bird fauna. Archive image.
There are also many difficult-to-explain changes in the statistics. It has been common wisdom that the birds of the mountains will have a hard time when the heat rises. Nevertheless, two of the typical small waders of the mountain moors, the pied piper and the marsh plover, have increased significantly since the turn of the millennium. The same applies to the mountain lab.
— It is strange. But factors other than temperature may have been more important, such as rainfall or the availability of food, says Wirdheim.
Longer species list
One thing is certain – the Swedish list of our breeding birds will get longer over time. Since 2000, only one species has disappeared from the country (black-legged sandpiper), while six new species have been added: cormorant, egret, black-capped gull, black-billed scrubby, fire-crowned kingbird and garden treecreeper. All of these, except the top cormorant, come from further south.
The bee-eater is a heat-loving species that is probably entering Sweden. Archive image.
— We can also count on spoonbills and egrets quite soon. Both are spreading northward. The bee eater is coming soon too. It has increased strongly in Germany recently, says Wirdheim.
The question is whether this is positive or negative. Anders Wirdheim is somewhat happy that birds like the bee-eater are on the way – it is a very beautiful bird – but at the same time feels sad about the changes.
— I think that we, Sweden, will manage fairly unscathed when the climate changes. But in other areas, such as in the mountain rainforests of the tropics, large numbers of species will be lost, he says.