The Return of Native Nordic Fauna

A research blog exploring animal reintroduction history by Dolly Jørgensen

Category: wild boar

Learning from wild boar

On 9 April 2015, I got to participate in a workshop on the potential opportunities and costs of reintroducing wild forest reindeer to Sweden. When Stig-Olof Holm publicly proposed bringing back the forest reindeer about a year ago, I was cynical to the idea. So when I was invited to talk about historical reintroductions in Sweden at a stakeholder workshop, I was both interested in sharing my historical viewpoint and hearing how others thought about proposed reintroduction.

WildBoar_Riga

Wild boar on exhibit at the Latvian Museum of Natural History, Riga.

Rather than talk about forest reindeer (which I actually know very little about), my presentation focused on historical reintroductions in Sweden. It included a section on the wild boar. Wild boar was originally one of the three animals I was going to deeply research in my project (beaver and muskox are the other two), but because of time limitations, I had to drop most of the work on it. I do, however, have a basic sense of the conflicts over wild boar in Sweden.

Wild boar had existed in Sweden in the Stone Age, but after that point it gets very tricky to distinguish between wild boar and domestic pigs in the archeological record. Some wild boar were probably in medieval game parks to be used in noble hunts, but some also may have been roaming the forest as late as the early 1600s. When King Fredrik I decided to reintroduced wild boar to Öland (a large island southeast of the Swedish mainland) in 1723, he wanted them as hunting quarry. But the Öland farmers were not at all pleased at the idea of having wild boar running around and damaging their crops. Their objections carried the day and a decision was made to exterminate them in 1752. Within 15 years, they were gone.

Wild boar continued to be popular game park animals. In the 1870s, for example, wild boar were brought to a Södermanland game park by Oscar Dickson, a Swedish magnate who owned among other things the sawmill Baggböle near Umeå. Game parks are notorious for animal escapees. With stone fences and ditches, some animals are bound to escape. In the early 1940s, some boar who presumably had gotten out of parks were free living, but these were hunted down by a state-sponsored hunt.

Populations that had been in game parks in Skåne and Södermanland once again became free living in the 1970s. This prompted the government to commission a report “Vildsvin i Sverige”. An inventory was made in 1979 and found small boar colonies (10-20 animals) in numerous counties. The largest population, probably 50, was found in Tullgarn-Mörkö area on the border of Stockholm-Södermanland county line. After the report was issued in 1980, the Parliament decided was that the boar population should be held under control, with less than 100 animals in Stockholms län and none in the others.

Wild boar statues in the "Swedish nature" exhibit of the Swedish Natural History Museum, Stockholm.

Wild boar statues in the “Swedish nature” exhibit of the Swedish Natural History Museum, Stockholm.

I’m not sure what action, if anything, was taken to bring about this desired reduction in number. In any case, it didn’t work. I think the position against boar continued to be debated and finally in 1987 the Swedish Hunting Law (Jaktlagen) declared that wild boar were part of the Swedish fauna. From that point on, recreational hunters would be the only control for the population.

Apparently, they’ve not been able to keep up with the pigs. Although hunters have ramped up hunts for wild boar–killing over 65,000 animals in the 2009/10 season–the boar population is growing exponentially every year. The current estimate of wild boar in Sweden is over 100,000 animals. As you can guess, there are some huge problems with the boar population growth, including significant damage to farmlands and crops and growing numbers of traffic accidents (3,714 in 2014). There are also concerns about cross breeding with domesticated pigs, as well as potential disease transmission between the wild and domestic pigs.

So why talk about wild boar at a workshop on reindeer? Well I think looking at the way historical reintroductions has worked (or not) can give us insights into possible issues with future ones. There are some key lessons about the wild boar:

  • Animals with high reproduction rates can only be contained in population & area if done early.
  • Animals spread outside of the areas in which they are first reintroduced, sometimes establishing populations very far away.
  • Increases in traffic accidents and conflict with rural land use should be expected with game reintroductions.
  • Animals can breed with others of the same species, even if we think of one version as wild and the other as domestic, and may be disease transmitters.

All of these are potential issues that would need to be considered in the case of the wild forest reindeer. It was obvious from the presentations that the Sami reindeer herders are vocally against the plan because of potential mixing of the wild type with their domestic herds. Although the idea is to reintroduce the wild reindeer to specific places, the animals most certainly will not just stay where humans put them, as evidenced by the distribution maps of the reindeer reintroduced in Finland presented during the workshop. The hunters support the reintroduction plans because they see the wild reindeer as a potential prey, but I got a very negative response from the Svenska Jägarforbundet representative to a suggestion that some areas might need to be set aside from all hunting to aid in the reindeer establishment. These are all positions that we can predict if we look to history. We can also see that pleasing everyone is nearly impossible, so if wild forest reindeer are reintroduced in Sweden, conflict should be expected.

Short-term thinking

The Norwegian newspaper Aftenposten ran a feature article a couple of weeks ago about alien species with the dramatic, quantitative headline: “2320 nye arter har kommit til Norge — halvparten er uønsket” (2320 new species have come to Norway — half are unwanted). Because the huge image at the top featured a muskox, it caught my eye.

Aftenposten_Jan2015

The article doesn’t really say much new. It covers the definition of “fremmed art” (alien species), which is defined according to the Norwegian Natural Biodiversity Law (Naturmangfoldloven NOU 2004: 28) as “en organisme som ikke hører til noen art eller bestand som forekommer naturlig på stedet” (an organism which does not belong to a species or population which exists naturally in the place). Then the article goes over some examples of the “new species” in Norway, including muskox about which the article says, “A concrete result is muskoxen in Dovre, where the first animals came from Greenland in the 1920s. Even though we know muskoxen lived in Norway earlier also.” It is this statement which brings up the time question in my mind–a question that I’ve discussed before, including a comparison of different European countries choice of cut-off line for “native” species.

Fremmedearter2010_Boks2 The Norwegian list of alien species which came out in 2012 specifically had a call-out box discussing the issue of time. It sets up 1800 as the point at which “alien species” arrived in Norway — if the species was here before then, it is not considered alien–except in the case of muskoxen and wild boar “which had lived in Norway in prehistoric time and then reintroduced at a much later point in time.” If we compare the law definition with this report’s use, we see that “existing naturally” as specified in the law takes on a time perspective that it didn’t previously have. Now a species is not natural if it was not in Norway as of 1800 whether or not it had been there previously.

The thing is, people didn’t used to think this way about time. In the writings of Adolf Hoel, he makes it clear that he is bringing back muskox to Norway, where they previously had been. “It means so much more that muskoxen have lived in our land during and even after the ending of the Ice Age,” he wrote in 1929. In 1930, he lauded the project as “also interesting that muskoxen will again be a part of the Norwegian fauna.” For Hoel, the muskox was not an alien species, but a native species coming home.

There has been much criticism as of late about historians thinking too short term (see Guldi & Armitage’s The History Manifesto, although I’m not saying I agree with their methods or findings), but I think the natural sciences are much more guilty of that kind of short-term thinking. I get the feeling that many scientists are trying to keep things they way they are right now or recover what has only recently been lost (this is, after all, the definition of conservation biology). In the Alien Species report’s box shown above, the authors made the point that 1800 was chosen because data was more available after that. While it may be true that there is more data, does that make the date a “good” one? I’m reminded of my critique of the conflicting IUCN definitions of reintroduction which seemed to privilege certain kinds of knowledge (specifically Western written records) as the only way of knowing if a species had previously been in an area. It becomes a question of what qualifies as historical when talking about natural history, where the data sources can reach long into the distant past.

As a closing thought, if Methusela, Sarv-e Abarkuh or the Llangernyw Yew, which are all over 4000 years old, were writing definitions of “alien” species, would the definitions would favour such short time scales? I doubt it. Being around a long time would change your perspective on what belongs and what doesn’t. Maybe we should start thinking more like trees.

A mixed population

Today I taught an advanced undergraduate class on Ecosystem Management here at UmU and gave a lecture on reintroduction then led a discussion section. The discussion centered on Martin Goulding’s “Native or Alien? The Case of the Wild Boar in Britain,” which is one of the bright spots in the Invasive and Introduced Plants and Animals: Human Perceptions, Attitudes and Approaches to Management edited collection that I criticised in a previous post.

In our discussion, one of the students commented on how strange it was that the wild boar were seen as aliens and rejected when they were thought to be hybrid animals (wild boar crossed with domestic pig) but after genetic studies showed that continental wild boars were just as genetically mixed, the wild boars in England were native and more acceptable. I completely agree. After all, if it looks like a wild boar and acts like a wild boar, isn’t it close enough to be a wild boar? Maybe, maybe not.

I think with today’s advancing genetic science, conservation decisions are increasingly being made on genetic grounds. I recently read an article about the recommended source of beavers for reintroduction to Great Britain (Halley 2011 in Mammal Review). It turns out that the European beaver (Castor fiber) has been previously divided into 8 subspecies based on the remnant populations that survived to the 20th century. That means that the ones in Norway were classified as C. fiber fiber, the ones along the Elbe as C. fiber albucus, the ones along the Rhône as C. fiber galliae, etc. This was based on very small differences in cranial morphology. I can only think of phrenology here and the attempt to classify people into subspecies by their cranial morphology. It’s funny how the same idea in animal species has been allowed to persist without comment much longer.

Graphic from Halley 2011 showing the similarity of the genes of different beaver populations: (fi) Telemark, (ga) Rhône, (al) Elbe, (bi) Mongolia, (po) Ob, (tu) Yenesei, and (in) Pripet/Voronezh

Graphic from Halley 2011 showing the similarity of the genes of different beaver populations: (fi) Telemark, (ga) Rhône, (al) Elbe, (bi) Mongolia, (po) Ob, (tu) Yenesei, and (in) Pripet/Voronezh

Halley, on the contrary, points out that genetics divide the extant beaver population before the 20th century reintroduction into western and eastern evolutionarily significant units (ESUs). The remnant populations in Norway, Germany and France that survived to the 20th century are all closely related and have low genetic diversity because of the low population levels in the “founder” remnant populations. The eastern populations in Ukraine and Belarus and China are put into another group, although these are much less closely related to each other. This leaves a “hybrid” group with mixes of east and west.

So why does this genetic tree matter? In the IUCN Guidelines for Re-introductions from 1998, it states

the source population should ideally be closely related genetically to the original native stock and show similar ecological characteristics (morphology, physiology, behaviour, habitat preference) to the original sub-population.

Thus, when new reintroduction projects are undertaken, if they are to comply with the guideline, the beavers should be as closely related genetically as possible to the original population of the area.

The problem Halley identifies with this approach is genetic bottlenecks. The beavers in the western ESU all got down to very small populations, and thus may have lost genetic diversity. Reintroducing from a single stock would be “to reintroduce only a fragment of the genetic variability formerly present.” Thus, he advocates that a mixture of beavers from all three of the western refugia stock be used in reintroduction in Great Britain. He also points out that mixing in eastern individuals would maximize genetic diversity, even though such a decision would be contrary to the IUCN guidelines. Halley’s suggestion to bring in eastern stock was vehemently rejected in 2012 by Rosell et al. who argued that such mixing was clearly against the guidelines and should under no circumstances be taken forward.

Where does this leave the beaver in the UK? The trial reintroduction in Scotland includes only beaver from Norway. Perhaps if a full scale reintroduction is undertaken, beavers from the other western groups will be mixed in, but the eastern groups will likely be left out.

To me, dividing the European beaver into genetic groups that shouldn’t be mixed can be dangerous. It seems all too reminiscent of fears about racial mixing in general. While I understand being careful about reintroducing the “wrong” species — like bringing the North American beaver (Castor canadensis) to Europe where it shouldn’t be — eastern and western populations of Castor fiber are still the same species. If the argument is that these beavers shouldn’t interbreed because they are genetically not identical, then from a philosophical position the same should apply to different breeds of dogs or people from different ethic backgrounds — and we all know that such a position is absolutely unacceptable. If there are geographical boundaries that would have kept these populations clearly isolated forever (like what happens in island geographies), then it might be more reasonable to keep them apart, but that’s not the case here. Instead, beavers in the geographical middle of the range are “hybrids” between west and east. It goes to show that the populations regularly mixed in the past and will continue to do so. This mixing may be a critical part of the gene flow that has kept beavers healthy and competitive. Mixing is not the unnatural thing it’s been made out to be.

Wild boar woes

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?

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