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SE: Inbreeding also with immigrated wolves

Roughly translated by TWIN Observer

Inbreeding has long been a threat to the Swedish wolf strain. The need for new blood from the Finno-Russian straom is great. But now a study shows that even some immigrated wolves from the east are more or less inbred.

Roland Johansson TT

“It’s surprising. Everybody assumes that immigrants start from scratch with regard to family relationships. But to some extent, some of them are inbred already from the beginning, “said Hans Ellegren, professor of evolutionary biology at Uppsala University.

This was the clearest for two eastern wolves that 2013 appeared in Norrbotten, and then transported down to Tiveden.

” They were very close relatives, maybe even siblings,” says Ellegren.

Small wolf in the east?

He suspects that the reason is that the wolf in the east, on the border between Finland and Russia, has been quite small.

This may also be due to the fact that the wolves who immigrated to Sweden found themselves furthest in the population where the chance of finding a partner is as the least. Then they might bred with relatives.

However, it should be noted that this does not apply to all immigrated wolves. Some of them have been free from inbreeding.

In the study, published in Nature Ecology & Evolution, Ellegren and his colleagues have sequenced the entire legacy of 97 wolves from the Scandinavian tribe.

This is the first time this happens. Previously, the researchers have only examined single parts of the genome.

Hot to survival

The results show that the Scandinavian tribe is more inbred than previously thought.

” The most remarkable is that whole chromosomes lack genetic variation,” says Ellegren.

The question is what this means for the wolf strain. It is generally assumed that the degree of inbreeding that the tribe exhibits poses a threat to its survival in the long run.

” But we do not know how big the threat is. It is difficult to know when and when the ineffective effect is going through. From a genetic perspective, it is absolutely necessary to bring in more unrelated individuals in the tribe, “says Ellegren.

Facts: Wolf

The wolf was originally found throughout Sweden, except for Gotland. It was common until the 1850s, but then declined rapidly due to hard hunting pressure.

The decline continued until 1966 when the species was close to elimination. The listing as protected came almost too late, when only a handful of wolves were left. The species was extremely close to extinction until the beginning of the 1980s when a wolf began to propagate in Värmland.

In the early 1990s, the number of pairs increased and since then the strain has increased from a dozen individuals to the top 415 wolves winter 2014-2015. Thereafter, the number has decreased slightly, to about 350 wolves in the winter 2016-2017.

Source: SLU

Hans Ellegren
Roland Johansson