An Excerpt from:
Ned K. Johnson and Joseph R. Jehl, Jr.
Studies in Avian Biology No.15:1-3, 1994
The most pervasive cause of negative [bird] population trends continues to be outright habitat destruction, with clear documentation of declines or extirpation of birds requiring riparian woodland, old-growth coniferous forest, grassland, saline lakes, marshes, and coastal beaches. .....
Many authors properly lament the massive role played by humans in destroying natural landscapes and the birds they support. Recognition of this fact over the last decade or more has led to commendable conservation efforts, with some outstanding successes. We can be heartened by increasing public concern for the environment and expanded general efforts to protect biotic diversity. Despite these gains, however, the long term prognosis is bleak. Incomprehensibly, national and international political leaders and the media either do not believe or will not discuss the connection between continued growth of the human population, with its attendant multitude of human social ills, and degradation of the world's resources. How ironic that overpopulation, the most pressing problem for ourselves and the earth's biota, is not only routinely ignored but its urgency is completely unappreciated. In company with many others, we conclude that all conservation efforts are doomed to eventual failure without prompt stabilization of the human population, which is now expanding at the rate of approximately one million every four days.
[Note: Dr. Johnson at the University of California at Berkeley is the top avian systematist and ornithologist in California. Dr. Jehl of Hubbs Sea World Research Institute is the foremost North American authority on birds of saline lakes.]