Sunday, 17 February 2013

A wolf in ecologist's clothing

It’s cheering when mankind does something right, isn’t it?

After all, we get plenty of things wrong. For instance, the northern United States ran an intense eradication campaign against wild predators (no, I don’t mean red-neck Republicans, though that would have made more sense) which led to the shooting of the last wolf in the Yellowstone Park in 1926.

For several decades afterwards, elk numbers grew vertiginously and their impact on the park was massive and deeply damaging: in particular, numbers of certain types of plant, including willows, fell drastically.

Mankind got something right.
Though the elks probably don't agree

In 1995, a final legislative hurdle was overcome and wolves were reintroduced to the Park. At the latest count, there are 98 of them in ten packs and the population seems stable. A new ‘apex predator’ has apparently been successfully brought back into a remarkable natural environment, a new top added to the food chain.

The impact has been swift and hugely positive. For instance, wolves often leave part of their kill and other animals scavenge on the remains, leading to their populations growing. That includes the bald eagle, a creature so iconic in the US that it even appears on banknotes (though I suspect it doesn't fully appreciate the honour).

More surprisingly, watercourses are flowing more truly and silting less; as a result all sorts of aquatic insect populations are thriving, and with them the birds and fish that feed on them are growing in numbers; indeed, the clearer, deeper streams are themselves contributing to rising fish populations, as they find more favourable spawning grounds.

Even the beavers are doing well: from just one colony prior to reintroduction, there are now nine in the park. That also helps improve the condition of the rivers, by regulating flow and creating a new natural environment for insects and therefore fish to thrive around the dams.

How was this all achieved through the simply reintroduction of wolves?

The first and most powerful impact was on the elk population, down 50% since the wolves returned. 
Nor is it just a matter of a reduction in numbers: the presence of the wolves keeps the elk stressed and on the move, so they don’t just stay in one area and strip it bare of vegetation. 

Now I know about stress and constant movement, with a career spanning a dozen jobs and then some, so I sympathise with the elk but, hey, the benefits for everyone else are just enormous: keeping them down and keeping them moving takes the pressure off so many others. The river banks don’t get trampled to death any more, plants on which so many others depend are surviving and even the willows are making it to maturity again – which is crucial, in particular, for the beavers.

There has also been a drastic reduction in the number of coyote. The ones that remain also tend to keep away from the valleys these days, though they dominated them before the wolves came back: a wolf is likely to catch a coyote on the flat but on mountain slopes, coyotes have developed a trick I’m sure you’ll agree is pretty astute: they lead a wolf on a downhill chase, then suddenly spin round and head back uphill; the bulkier wolf has trouble making the turn, giving the coyote the chance to build a significant lead.

Substantially reducing the number of coyote has allowed foxes to re-emerge in larger numbers. They have have an impact on the rodents and other small animals predated by both coyote and foxes, and in turn that influences the proportions of different seeds that germinate and plants that flourish.

The reintroduction of the wolf has hugely changed the environment at Yellowstone, and almost entirely for the better. It’s as though well-intentioned but badly planned human intervention had been recognised for what it was, a serious error, and steps taken to correct it.

Wouldn’t it be nice if that happened more often?

Coming next: 

  • western governments correct fiscal policies based on the erroneous concept of ‘trickle-down’; 

  • western governments correct foreign policies based on the erroneous concept that decency and democracy can be exported by torture and drone strikes; and biggest of them all, 

  • western governments correct energy polices based on the erroneous concept that natural resources are infinite and their use has no impact on the environment.
Doing well in Yellowstone.
Excellent news for us all


Awoogamuffin said...

That certainly is a great story about the wolves! Where'd you hear about it? As for the other stuff happening, I won't hold my breath

David Beeson said...

It was a BBC nature programme - supplemented, I have to confess, by good old Wikipedia...

David Beeson said...
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