What’s killing the songbirds?

A York University professor’s new book is raising the alarm about an environmental crisis that threatens our forests and the battle against global warming.

In Silence of the Songbirds, biologist Bridget Stutchbury (left) argues that songbirds are disappearing from our skies – an environmental danger sign equivalent to canaries in a coal mine.

"We’ve lost nearly half the birds that filled our skies just 40 years ago," says Stutchbury, who is York’s Canada Research Chair in Ecology and Conservation. "This is not just an endangered species problem. What we’re facing is a severe loss of ecosystem that comes with removing millions of birds from our forests each year."

This year marks the 100th anniversary of the birth of American environmentalist and author Rachel Carson, whose 1962 book Silent Spring first warned of the dangers of the pesticide, its detrimental impact on the world’s bird population and its threat to human health. Stutchbury has devoted decades to the study of migratory songbirds and how their habitats are linked with our ecological well-being. Her book details the 10,000-kilometre migratory journey of songbirds from Canada to South America and highlights the environmental threats faced by songbirds. She illustrates that little has changed since 1962.

What’s killing the birds? The prime offenders, says Stutchbury, are pesticides and destruction of tropical habitat.

"The switch to sun-grown coffee has pushed birds out of their forest refuges in traditional shade coffee farms so we can get a cheap morning fix," she says. "So, even something as simple as your morning coffee has critical impact."

Silence of the Songbirds highlights how a shade coffee farm is a mini-ecosystem. More than two dozen different species of trees shade the coffee plants below and provide a home for plants and animals, including songbirds. On a shade coffee plantation in Chiapas, Mexico, a bird survey found 46 species of songbird migrants, including 22 species of warbler.

In the 1970s, many coffee growers in South and Central America cut down their trees and planted a sun-grown coffee species to halt an outbreak of coffee leaf rust. Without the shade trees that naturally provided nutrients and gave a home to insect-eating birds, these plantations now depend on chemical fertilizers, herbicides, fungicides and insecticides to keep pests at bay.

While Carson’s efforts and writings did much to rid the world of DDT, today’s pesticides pose significant threats to the world’s songbird population. Stutchbury documents the impact of chemicals such as chlorpyrifos and diazinon, that are acutely toxic to birds, which are still widely used on vegetable and fruit crops in the United States and Canada.

The destruction of vital habitat extends right from Canada’s shrinking boreal forests to the tropical jungles of Brazil and to the grasslands of Argentina. Even the bright lights and structures of our cities prove to be a minefield for migrating birds.

"One single building in Chicago used to cause 1,500 migratory bird deaths each year until they turned their lights out," Stutchbury notes. Now, as part of the Lights Out campaign, almost all of Chicago’s major skyscrapers turn off their flood lights during the main bird migration season. Yet the lights remain on in many North American cities, including Toronto, and the carnage continues – more than 600 ovenbirds and 800 Tennessee warblers were killed by flying into two towers in Nashville in one night.

"Without birds to disperse fruit, many native shrubs and trees cannot move their seeds, and without birds to eat bugs our forests face infestation. Without healthy forests, we lose a vital tool in the fight against global warming," Stutchbury says. Songbirds also help in natural control of agricultural insect pests, which eat up to 20 per cent of our crops before and after harvest.

Ten ways to help migratory songbirds, from Silence of the Songbirds

  • Buy shade coffee
  • Buy organic produce from tropical countries (e.g. bananas, pineapple)
  • Buy organic for crops that pose the greatest pesticide risk to birds (e.g. potatoes)
  • Go pesticide-free on your lawn
  • Buy wood and paper products certified by the Forest Stewardship Council
  • Buy paper products (e.g. toilet paper, paper towel) made from recycled paper
  • Turn your office and household lights off at night during migration
  • Reduce bird-window collisions by moving bird feeders
  • Make your backyard bird-friendly by planting shrubs and trees
  • Keep your cat indoors

For more information on Silence of the Songbirds, click here.

For information on shade coffee, visit York’s Las Nubes Web site.