By Sunniva Midtskogen
A video on the effects of reintroducing wolves into Yellowstone National Park in the United States circled around the internet recently. It is a fascinating study that started 22 years ago and has gone viral more than once. It proves to me once again how perfectly balanced the natural system is. There is a phrase for the effect the wolves had on the park: trophic cascades. This basically means that an ecological process starts from the top of the food chain and tumbles on down the system.
The grey wolves came from Jasper, Alberta in January 1995. There were eight of them to start with, and they were the first wolves in the park since the 1920s. The effects were both slow and immediate. The first thing that happened was that the deer population changed. It dwindled due to the wolves’ hunting, but more importantly the deer’s behaviour changed: where before they had been able to roam the park freely, they started to avoid places where the wolves would be able to hunt them easily. Valleys and gorges began to blossom as the deer no longer grazed them. Forests grew, which brought back song birds and beavers. The beavers would build dams from the trees, creating pools where an entirely new ecosystem thrived, consisting of amphibians, otters and more.
The coyote population was also reduced by the wolves, causing an influx of rodents, which in turn brought hawks, eagles, foxes and weasels back to the park. The bears also thrived, eating scraps left from wolves and the lush berries growing where the deer used to graze. The way the food chain was affected by these few wolves is in itself spectacular, but amazingly it doesn’t stop there. The whole physicality of the national park changed as a direct effect of the wolves; after the deer abandoned the more open spaces and the earth could grow trees and bushes, the river banks stabilised, fixing the rivers in place. Soil erosion had let the rivers meander and change, but the effects of the wolves cascaded down the food chain and as a result the soil got firm enough to direct the flow of water in a steady direction.
In my home country of Norway, we have an election coming up, and one of the topics the parties are most divided on is the topic of wolves. The wolves in Scandinavia were almost extinct in the 60s, and in the 80s the whole of Norway, Sweden and Denmark had only one pack of around 10 wolves. It is a topic the politicians cannot agree on: it is a hard decision between protecting an endangered species and protecting our domesticated livestock, a highly important industry.
We always think that it is up to us to make these decisions, when nature has such a powerful way of figuring it out on its own. A wonderful example is the way the classic science-fiction novel by H G Wells The War of the Worlds ends: the alien invasion that threatens us dies from an earthly virus. We humans struggle and research and hustle to try to fix whatever problems we have, sometimes finding a way through science. Sometimes what science tells us is that we need the wolves to come back. Unfortunately, the problem with the wolves in Norway has no easy solution: it’s either the wolves or our sheep. If the wolves get to roam free, farmers will lose their livestock and be forced to leave the villages, which in turn causes urbanisation. A direct opposite effect of what the wolves achieved in Yellowstone.
So although I cannot decide what to think of our wolf problem in Norway, I found the story about the wolves in Yellowstone to be many things: humbling, inspiring, incredible. In the bustle of all that comes with being an active member of our society, all the problems we cause that seem to have no easy solution, it is nice to think that in Yellowstone the ecosystem is more diverse and more stable because eight wolves were left to just do what they do.