I watched a fantastic documentary on BBC4 last night which demonstrated how the reintroduction of wolves into Yellowstone National Park in the United States benefited the entire ecosystem almost immediately. Part of the Nature’s Microworlds series, it’s well worth catching on the iPlayer if you get a chance.
Wolves had been eradicated from the park 70 years earlier as part of pest-control measures (yes, really) and were reintroduced in the 1990s. Here’s what happened.
- The population of coyotes, which had grown out of control from having no predators or competitors, shrunk to more natural levels
- With the coyote threat reduced the population of pronghorn antelopes rose immediately (they are too quick for wolves)
- Bears benefited because wolf packs often leave behind unfinished carcasses for them to scavenge
- The elk population, which had become accustomed to eating tree saplings on riverbanks, moved to less open areas where they were at less risk from wolf packs
- With the elk gone, riverbanks which had become sandy and silted started to grow birch and aspen trees again
- Beavers returned to the riverbanks and started to build dams from the newly grown trees
- Beaver dams caused an increase in water-borne plants
- More water-borne plants meant a richer habitat in the rivers and more fish
- More fish in the rivers meant an increase in the otter and osprey populations
A positive story all round, you would think, but there is a sting in the tale which wasn’t covered in the documentary. In December one of the alpha females featured in the programme was shot and killed quite legally by a hunter in Wyoming. The wolf was wearing a scientific monitoring collar, and three more collared wolves from the reintroduction programme have also been killed. Why is this happening? I don’t pretend to understand the motives of hunters, but perhaps a parallel here in the UK is the farming community that wishes to cull our native population of foxes and badgers. An item on the wolf-hunter story in Yellowstone was published recently in Outside magazine.
The reintroduction of wolves into the Scottish Highlands has often been talked about, and after watching the BBC programme it seems obvious that Scottish wildlife will benefit in the same way. Much of the Scottish countryside has long been denuded by red deer which no longer have any natural predators. There would probably be no trees at all were the red deer population not culled by humans every year.
It’s unlikely wolves will be reintroduced into Scotland any time soon. The move would be too controversial, and hill walkers like me would have to take up fencing in order to learn how to fend them off with our trekking poles. Personally, though, I’d much rather see wolves on the hills than wind farms.
