A century ago introducing new birds to North America was something of a fad. People who did this sort of thing called themselves acclimatizers. They formed societies such as New York’s American Acclimatization Society to pool their resources so they could buy more birds–mostly in Europe–and import them to North America. We owe our starlings to the New York group. A similar society in Cincinnati imported more than 70 species of European songbirds during the last three decades of the 19th century. None of those birds survived.
Best of Chicago voting is live now. Vote for your favorites »
The rest of us have supposedly gotten too aware of the glories of American nature and too sophisticated in the concepts of ecology to be attracted to either the acclimatizers or the casual slaughterers. Or so I thought. Lately I have been taking part in discussions about preserving and restoring the natural wonders of the Chicago area–don’t laugh; we have them in abundance–and some of what I have heard suggests that the spirit of acclimatization is still very much alive.
The root of the problem seems to be confusion over the concept of biodiversity combined with a failure to recognize the reality of biological communities. Biodiversity has become a buzzword among those of us who are into the protection of nature. Indeed some people I know can scarcely string together four sentences without using the word at least once. “Biodiversity” may not be the most felicitous coinage in history, but it describes something quite real and quite important: the glorious profusion of nature, the clear evidence that God is not an accountant. Or to put it more plainly, the clear tendency of life to evolve in the direction of endless variety.
The community modifies the physical environment in countless ways. It is shadier, wetter, and cooler under a canopy of trees, and most prairie plants cannot grow there. Spruce and fir trees create acidic soils, and only plants adapted to those conditions can thrive in a spruce-fir forest. When sea otters were nearly extirpated from the kelp beds of the Pacific coast, the kelp beds themselves disappeared–along with the myriad crustaceans, mollusks, small fish, and algae that lived in the beds. Sea urchins, whose principal food is kelp and whose principal predator is the sea otter, had enjoyed a population explosion in the absence of otters. Now that sea otters have been reintroduced, the kelp beds are coming back. Midwestern oak woods have a rich herbaceous understory that provides fuel for frequent fires that keep the woods open and sunny, providing perfect conditions for reproduction of both the herbs and the oaks. Insert an exotic species like the tall shrub called common buckthorn, and its dense shade prevents the growth of the herbs, stopping the fires, and ultimately destroying the oak woods.
The flood of humanity into every corner of the natural world has made ark building one of the most urgent tasks of our time. To be successful ark builders we must recognize that our arks have to be designed to hold communities, not individual species. The lone species is like a human in a refugee camp, a creature without context, robbed of family, work, associates, and everything else that makes it possible for life to go on.
