First in a series
Many causes contribute to the losses. Solutions will be just as complex.
Three billion birds have vanished in North America in the span of a single lifetime. They’re just gone. It’s as simple as that. But at the same time, this staggering finding from the study of bird populations published last weekj in the journal Science is so complex — the number so large — it’s hard to get your arms around it.
What does it mean to the environment, to the balance of nature, to the species themselves, that roughly a quarter of the avian population has disappeared since 1970?
In the coming weeks, we’ll explore these and others questions raised by the research that has uncovered a crisis over the future of birds in U.S. and Canada. Upcoming posts will look at why people should care, what these findings mean for other segments of wildlife and where the research will go from here.
The study shows that a combination of forces more powerful than previously thought is wreaking havoc across almost all bird species, according to its authors, scientists and researchers from the Cornell Lab of Ornithology, the Smithsonian, the American Bird Conservancy and four other institutions.
Some of the causes are indisputable: The most obvious is the way the places birds live are being developed at a pace affecting not just endangered species but our most common birds as well. It runs from the general to the specific. For example, the loss of grasslands to farming and housing has cost of the lives of half the Eastern and Western Meadowlarks and a huge numbers of sparrows. Many coastal species are hurt by the fact that so many people now live along beaches and waterways that birds are being squeezed out. At the same time, rising water levels are impacting the shallows where many species live and breed.
And then there’s the problem of insects. As their names imply, species like flycatchers and swallows survive on bugs, and they’re disappearing, too, due in part to newer types of powerful insecticides called Neonicotinoids. Warming trends are throwing off the life cycles of birds and cutting into their nesting and breeding seasons that fuel future generations.
A Scientific American graphic on the study.
The declines have been devastating to birds, but they also signal broader shifts in environments that all life forms depends on.
“We can do better, and we must, if only in our own self-interest, because trouble for birds means trouble for us as well,” Cornell Lab CEO John Fitzpatrick and Peter Marra, director of the newly created Georgetown Environmental Initiative, wrote in an essay for the New York Times this week.
While some causes are clear, the declines of certain species mystify researchers. The loss of millions of migratory birds — which make up about 40 percent of overall population — are a puzzle, since they rely on environments spread all across the hemisphere and make arduous trips twice a year that expose them to all sorts of hazards.
