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The ecology of predatory politics

By Clark Nida

Working my way patiently through an audiobook of Charles Darwin’s The Origin of Species. It’s heavy going, but stuffed with hidden gems.

Everyone knew in Darwin’s day how breeders cross specimens of different varieties to get variants of a given attribute lying on a scale between end-points represented by the parents. But this does not explain how an attribute, like the woodpecker’s beak, can grow virtually without limit beyond the range seen in the fossil record of its ancestors. Until he deals with that, Darwin cannot establish that the origin of species needs no other mechanism than that afforded by the production of varieties by selective breeding. But Darwin painstakingly searches out objections to his theory and demolishes them one by one with the application of his extensive knowledge, aided by evidence from his correspondence with field-workers in other lands.

At one point he musters evidence to show how an entire landscape can critically depend on a single species. The absence in Paraguay of feral cattle, dogs and horses he attributes to a fly which lays its eggs in the navels of newborn mammals: exterminate this fly, he claims, and the landscape would soon be drastically altered by browsing mammals.

Sometimes the chain of dependency is long, leading to unexpected effects.

Thus an excess of cats in a given neighbourhood can encourage the growth of heartsease (Viola tricolor). The reason is this: fieldmice destroy the nests of bumble bees, the essential pollinators of this plant. Introduce cats and the fieldmouse population plummets, allowing heartsease to flourish.

Having just heard that, my eye was caught by an article about the beneficial effects on willow from the reintroduction of wolves in Yellowstone Park.

http://www.bbc.co.uk/news/world-12634898

Let me quote:

Dr Smith has noticed dramatic changes amongst the willow stands that grow in Yellowstone’s river valleys. He said: “When I first came to Yellowstone about 16 years ago the willows here were all eaten by elk. But since wolves have been reintroduced we saw the willow come back, before our eyes. A big factor is, very simply, wolves eat elk, so it’s connected.”

For scientists like Dr Smith, the potential rewards of bringing back predators outweigh the logistical complexities and risks of their return. They believe we have to stop hating predators and learn to live with them, for our own good.

That insight, well-known to Darwin, has the potential to transform America – and indeed the world.

But Darwin has many enemies in the USA. Might those enemies be the very people who have most to lose by a change in the economic status-quo? If so, they are relying on the very principles of the man whose theories they resist: to keep the world safe for their destructive lifestyle they want to repopulate Congress with savage predators on needful public expenditure.