African forest elephants populations are declining rapidly due to local human pressures. But is it fair to expect other humans to live among potential threats to their livelihood? (Image Credit: Ray in Manila, CC BY 2.0, Image Cropped)
When species like this toucanet are lost, the interactions that they are a part of are lost too. So how can we restore them? (Image Credit: Jairmoreirafotografia, CC BY-SA 4.0)
Estimating interaction credit for trophic rewilding in tropical forests (2018) Marjakangas, E.-L. et al., Philosophical Transactions of the Royal Society of Biology, 373, https://dx.doi/10.1098/rstb.2017.0435
We have reviewed more than enough papers on biodiversity loss to entitle us to skip the whole “losing species is bad” spiel (see here, here and here). But what we haven’t talked about is that when some species are lost, specific interactions that those species participate in disappear from an ecosystem. Those interactions range from the minute to the crucial. One such crucial example is that of seed dispersal, whereby specific plants rely on specific animals to disperse their seeds, thus maximising biodiversity in other parts of the forest and creating a positive feedback loop.
Naturally, conservationists will want to reintroduce animals to propagate some of these reactions. But as is always the case in conservation, maximising return is absolutely essential when you’re faced with limited resources and a lot of ground to cover. Today’s authors wanted to develop a system for maximising the effect of species reintroduction.
Why support bringing species back?
Reintroducing species, or rewilding, can have effects well beyond making hippies in Green Peace happy. The reintroduction of beavers in the UK, for example, has reduced flooding in Devon, and the reintroduction of wild boar in Sweden has led to an increase in plant species across habitat types where the wild pigs rooted. The reintroduction of wolves to Yellowstone National Park in my home country the good old US of A has led to the natural regulation of deer and elk populations, in turn leading to more diverse forests as grazing of seedlings decreased.
Why not reintroduce species?
Reintroducing species has understandably led to controversy. Sure, wolves are cool-until they eat your sheep. Since wolves were reintroduced to Yellowstone in the 1990s, locals have protested citing safety concerns, the loss of livestock, and a decreasing population of elk for hunters. In Sweden, the boom in wild boar numbers has led to destruction of crops, and much outcry from farmers. Having protected species on land also makes it harder for companies to extract natural resources, both from a political and practical perspective (image a miner facing off with a bear).
The future of reintroducing species in Scandanavia
Species that are either being reintroduced in the UK and US or are under consideration are being hunted to extinction in Scandinavia. Norway, a country known for leading the change in environmental issues, is mired in debate over maintaining their current populations of large carnivores like wolves and wolverines. It seems unlikely that sheep farmers that have pushed for the cull of wolves to protect their flocks would support bringing in any more large animals that might pose a threat to their economic well being. If a species like wild boar are reintroduced to Norway like in Sweden and carnivore populations are kept low, hunting would be the main limitation to the population exploding to pig-pocalypse proportions.
Bringing back some of the species we have lost could bring back some biodiversity that we have lost. There will be short term costs, but the long term benefits of preserving biodiversity for future generations is immeasurable. However, I do think the Viking is best left extinct.
For more information on rewilding, we invite you to read the following works.
Feral by George Monbiot, The Return of Native Nordic Fauna project
The Sixth Extinction: An Unnatural History by Elizabeth Kolbert
