Friday, June 22, 2007

Species Deceases - Tens Of Millions Of Birds In America Disappear Without A Trace


The passenger pigeon, from 5 billion to none in 200 years

This report from the New York Times discusses the massive decline in bird numbers across the past few decades. Tens of millions of birds have just disappeared :

Last week, the Audubon Society released a new report describing the sharp and startling population decline of some of the most familiar and common birds in America: several kinds of sparrows, the Northern bobwhite, the Eastern meadowlark, the common grackle and the common tern. The average decline of the 20 species in the Audubon Society’s report is 68 percent.

Forty years ago, there were an estimated 31 million bobwhites. Now there are 5.5 million. Compared to the hundred-some condors presently in the wild, 5.5 million bobwhites sounds like a lot of birds. But what matters is the 25.5 million missing and the troubles that brought them down — and are all too likely to bring down the rest of them, too. So this is not extinction, but it is how things look before extinction happens.

The word “extinct” somehow brings to mind the birds that seem like special cases to us, the dodo or the great auk or the passenger pigeon. Most people would never have had a chance to see dodos and great auks on their remote islands before they were decimated in the 17th and 19th centuries. What is hard to remember about passenger pigeons isn’t merely their once enormous numbers. It’s the enormous numbers of humans to whom their comings and goings were a common sight and who supposed, erroneously, that such unending clouds of birds were indestructible. We recognize the extraordinary distinctness of the passenger pigeon now because we know its fate, killed off largely by humans. But we have moralized it thoroughly without ever really taking it to heart.

The question is whether we will see the distinctness of the field sparrow — its number is down from 18 million 40 years ago to 5.8 million — only when the last pair is being kept alive in a zoo somewhere. We love to finally care when the death watch is on. It makes us feel so very human.

Why are so many bird species racing towards extinction?

Agriculture has intensified. So has development. Open space has been sharply reduced. We have simply pursued our livelihoods. We knew it was inimical to wolves and mountain lions. But we somehow trusted that all the innocent little birds were here to stay. What they actually need to survive, it turns out, is a landscape that is less intensely human.

In our everyday economic behavior, we seem determined to discover whether we can live alone on earth. E.O. Wilson has argued eloquently and persuasively that we cannot, that who we are depends as much on the richness and diversity of the biological life around us as it does on any inherent quality in our genes. Environmentalists of every stripe argue that we must somehow begin to correlate our economic behavior — by which I mean every aspect of it: production, consumption, habitation — with the welfare of other species.

This is the premise of sustainability. But the very foundation of our economic interests is self-interest, and in the survival of other species we see way too little self to care.

The story of the decimation and extinction of the American passenger pigeon is a shocking story, probably even more so today. From an estimated population of more than 5 billion before Europeans arrived in North America, to none in less than 200 years :

They lived in enormous flocks, and during migration, one could see flocks of them a mile (1.6 km) wide and 300 miles (500 km) long, taking several days to pass and probably containing two billion birds.

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