We’ve written about this industrious animal before on these pages, but in a completely different light. As with many introduced species, there are frequently unintended consequences on a disastrous environmental scale when the species has no natural predators in their new locations. Indeed there are huge areas of new wetlands in Patagonia’s Tierra del Fuego, but at the expense of millions of trees. (It’s actually calculated that in Patagonia beavers cause the 15 tons of biomass per year.)
However the case in Northern England and Scotland is quite different.
Beavers lower the canopy around a water body by felling trees and digging canals – opening it up. Solar energy piles in to places that have been in shade for decades. They stir life into action, kicking up nutrients as they beaver about their daily doings. Nature loves change; it frees up opportunities. Species of every size and shape wade in and snatch their chances. Beavers shift everything, tirelessly, instinctively, creatively. That’s why ecologists call them a “keystone species”. By doing their own thing, they create habitats and opportunities for just about everything else.
Our nine years of soggy monitoring have demonstrated precisely what the scientific literature predicts. Measured against adjacent wetland the beavers have not utilised, we find that biodiversity has expanded by a factor of four.
That’s a 300% increase on the initial pre-beaver presence: more aquatic bugs for fish to hoover up; more fish for herons, diving ducks, grebes, otters and ospreys; more newts, frogs and toads; more insects for small birds to snatch; more small mammals, including water voles and water shrews, for owls and other predators. And so it continues up the chain: more food for pine martens, stoats, weasels, foxes, badgers; more and a wider variety of wild flowers and wetland plants. Altogether more of just about everything, in a happier, fatter, richer, healthier and more diverse ecosystem bubbling with life and energy.
That, you might think, would be justification enough to reintroduce the beaver, but it’s only half the story. The incidental benefits beavers deliver for free include flood retention, thanks to their small dams; preventing flash-flood siltation, which is a real hazard to young fish; and creating fish nurseries in their lagoons and ponds behind the dams.
The fact that these beavers are helping to maintain balance in the ecosystem can only be viewed as a good thing.
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