The wild boar is rooting up trouble in Norway, according to a recent article on ScienceNordic. In February 2013, for the first time in thousands of years, a wild boar was killed in Norway.

Rock art from Uppland, Sweden, showing wild boar. Enköpings museum, EK0136.

Rock art from Uppland, Sweden, showing wild boar. Enköpings museum, EK0136.

Wild boar were last roaming about the Norwegian countryside in the Stone Ages, 5000+ years ago, when they were used as a food source according to archeological finds near Stavanger. Sweden has a similar history of free-range wild boar — evidence points to them dying out 4000 years ago — but wild boar are also known to have survived in Sweden well into the 17th century in royal hunting parks. Needless to say, they were gone from the Scandinavian forests for thousands of years.

Now they are back. They were accidentally released in Sweden from hunting parks in the later 20th century. (I haven’t yet traced how those parks ended up to have wild boar in the first place – more research is ahead.) In 1979, a Swedish government inventory estimated 50 to 75 swine in the southern counties, resulting in an intensive hunt in 1980. The efforts clearly failed: the Swedish Hunting Association estimates 65,000 boar were shot in the 2009/10 season alone. Wild boar is thus fully reintroduced in the Swedish countryside. Rogue boars are now crossing the border into Norway and the alarm has been sounded.

Drawing of wild boar from A. E. Brehm, Däggdjurens lif, trans. Smith and Lindahl (1882)

Drawing of wild boar from A. E. Brehm, Däggdjurens lif, trans. from German by Smith and Lindahl (1882)

The wild boar (Sus scrofa) is on Norwegian Black List of invasive species. Because it has been absent from the area for thousands of years, it is considered an alien species, just like the muskox I discussed in a previous post. But unlike the muskox, the boar gets a designation of “WWIAS” – on the IUCN World’s Worst Invasive Alien Species list. Sus scrofa clearly is highly damaging in many parts of the world like tropical island ecosystems which evolved without it, but is the designation appropriate in the case of returning the wild boar to part of its prior range? Of course, that depends on how you define ‘prior range’, and in the case of the Norwegian Black List, a prior range thousands of years ago doesn’t count.

Norway is likely facing an influx of wild boar that cannot stopped. As Scandinavia gets warmer with climate change, it will be better and better habitat for the boar. The ecosystems to which they are returning will certainly be affected by the boar’s presence, but perhaps the evolution of those systems seen in long-time scales included wild boar so its return completes the system rather than destroys it. Should the boar’s re-entry into Norway be a day of rejoicing or sorrow?