Every five years, SLU (Swedish University of Agricultural Sciences) publishes an updated red list of individual species' risk of extinction in Sweden.
The next update will be published this spring, but a preliminary list was already published this summer, including moose and ferret as red-listed species.
The preliminary list of birds was also recently released – where both the snowy owl and the barn owl are proposed to be classified as nationally extinct. The last known breedings for the species are from 2015 and 2003, respectively.
At the same time, both the barn owl and the hawk owl are new to the red list.
It is a bit surprising that things are looking bad for so many of the owls, says Mikael Svensson, a biologist at the SLU Species Data Bank.
Things are also going badly for, for example, the barn owl, so it's something that happens at night, you could say.
“Crash” system
When it comes to the snowy owl – which has become famous not least thanks to the owl Hedwig in the Harry Potter films – it is the availability of small rodents that seems to be the problem.
"People have previously talked about lemming years, with rodent peaks in the mountains about every four years. But that system has crashed since the early 1980s," says Mikael Svensson.
It has had a huge impact on the snowy owl and other birds of prey in the mountains.
The cause of the rodent shortage is not fully understood, but climate change is believed to be an important factor.
The rodents depend on a stable snow cover, under which they can build walkways. But if the snow alternates between melting and freezing, there will only be ice crust on the ground.
Two mammals
On SLU's previous red list, there were just over 200 species that were classified as nationally extinct. This largely concerns various insects, as well as vascular plants, mosses and lichens.
However, there are also two mammals on the list – wild reindeer and black rat – as well as eight other bird species that were previously on the list.
However, the fact that a species is nationally extinct does not mean that it has disappeared globally, Mikael Svensson points out.
No, for example, there are still snowy owls in Norway, even though the situation there is very bad, he says.
SLU's red list is updated every five years and is an assessment of the risk of a species becoming extinct in Sweden.
A red-listed species is a species that is not considered to have a long-term viable population in Sweden and is at risk of disappearing from the country.
It is estimated that there are approximately 60,000 multicellular species in Sweden. For approximately 22,000 of them, knowledge is good enough to be assessed within the work on SLU's red list.
In the latest update, 2020, there were just over 4,700 red-listed species, of which just under half were assessed as threatened.
Source: Swedish University of Agricultural Sciences (SLU).
In addition to the snowy owl and the barn owl, which are proposed to be classified as nationally extinct on the next red list from SLU, there are already eight other bird species that are considered extinct in Sweden.
These include black-legged kittiwake, black stork, blue crow, common woodpecker, puffin, tufted lark, great bustard and hoopoe.
A handful of species are classified as critically endangered on the upcoming list: field pipit, common tit, black-headed gull, ortolan bunting, and southern marsh snipe (a subspecies of the marsh snipe).
Seven species are proposed to be removed from the Red List, including the white-tailed eagle and the great snipe. However, eight species are added, such as the hawk-owl and the barn owl.
Sources: Swedish University of Agricultural Sciences (SLU) and Birdlife.se.
