In a few pockets of the world wolves have been carefully reintroduced and the effects are proving enchantingly dramatic. With surrounding trepidation they were reintroduced to Yellowstone National Park in 1995. In the years that followed the effects of introducing a pre-existing apex predator have started to unveil. The beaver are being brought back to Wales, Trout to London and native pine trees to the Scottish Highlands.
“There will never be a healthy self sustaining eco-system until we get all the component parts back in place,” says Alan Watson Featherstone, founder of the charity Trees for Life. Although, quite understandably without rigorous management the idea of top evolutionary predators roaming the forests is potentially unnerving, with it however the effects are somewhat magical.
Take the wolf in Yellowstone, initially considered useful in controlling the rise of destructive herbivores, they have revealed themselves to be far more than simply killers, they also give life. Their presence in an ecosystem creates a trophic cascade, a tumble down effect between species.
By hunting they have changed deer behavior — under the watch of the wolf they no longer graze in valleys or gauges allowing the vegetation there to flourish with certain trees quintupling in size over six years. This draws back the birds, muskrats and beavers. Beavers— the ‘ecosystem engineers’ — then create habitat for otters, ducks and fish through their dam building.
The wolves also kill coyotes which mean more rabbits and mice which mean more hawks, weasels, foxes and badgers.
Other apex predators such as ravens, eagles and bears feed on the carcasses that the wolves leave behind. Steadily rising in numbers, they then reinforce the impact of the wolves by killing deer calves.
And most magnificently of all, by allowing forests to grow the wolves have changed the way the rivers move, the health of the water has been propelled and more habitats for more wildlife have been created. With less erosion, the creation of pools and ripple sections, animals have come to live once again in the rivers.
This phenomenon supports a shift in thinking amongst conservationists and governments. Legislation encourages rewilding and in March 2015 the Lynx UK Trust announced plans for trial releases. Once reintroductions have been facilitated nature then expertly rebuilds its heritage of secure ecosystems, brimming with webs and networks of species. Just like the wolf, many other apex predators catalyse a trophic cascade.
It has been estimated that bringing wolves back to Yellowstone National Park has created $35 million in tourist revenue, which more than covers the reintroduction and management costs. The Scottish Highlands however are restricted in roaming space with farms and livestocks interspersed across the landscape. Meaning with the propensity of wolves to travel large distances in search of territory and a mate a high level of long term costly population management is needed.
The debate on apex reintroduction — often between ecologists, farmers and hunters worldwide — reflects the challenges to overcome. How can we safeguard the farmers’ and hunters’ livelihood and provide security and answers to community concerns while letting apex predators embody ‘wild’ and perpetuate nature back into our forests and hillsides?
Reintroductions of the wolf, whale, lynx, bear, beaver and more to their native homes — whether it be Scotland, Siberia or the United States — depend on this delicate balance being met. Ecosystems were built in the presence of apex predators and as the evidence starts to reveal itself, we see that the biodiversity of life thrives with them.
To discover the intricacies of the wolf phenomenon and that of the whale trophic cascade follow the link to a short talk on ‘rewilding’ by George Monbiot below…