Ornithologists have noticed a significant decline in the numbers of migratory songbird species. Here’s an overview of the problem.
Stutchbury (Biology/York Univ., Toronto) begins with the tropical forests of Central and South America, and many islands in the Caribbean: second homes to our familiar birds. There they adopt a different lifestyle, fattening up for the flight back to their breeding grounds in springtime. But their southern homes are under severe pressure. Deforestation is a significant threat, as the once-solid ranks of trees come down to make way for cash crops. Prime habitat is being lost, and, along with it, food sources the songbirds depend on. Worse still, in many of the countries where they winter, birds are subjected to heavy doses of pesticides. Some birds are killed outright; others are simply so weakened that they cannot complete their migration north. Stutchbury offers positive suggestions, such as drinking shade-grown coffee, which minimizes deforestation, and buying organic food instead of pesticide-laced products. But there are other, less easily dodged problems. City lights and tall buildings are bird killers—many thousands of birds can crash into a TV tower or wind farm during the migration season. Domestic cats allowed to roam free are prolific bird killers, too—as are feral cats. Northern habitats are also under pressure—forest preservation not being the highest priority in North America. The result has been a steady and measurable decline in the populations of almost all the major migratory songbirds over the last several decades. Stutchbury emphasizes that birds are not the only threatened species: The loss of forest contributes to global warming, and the human population will inevitably suffer the consequences. She closes with a short list of countermeasures the average person can take to help save the birds.
A powerful warning, very much in the vein of Rachel Carson’s Silent Spring.