A dramatic decline in songbird populations during the past four decades is a warning to humans about the dangers of toxic farm chemicals, says a Canadian expert on bird populations.
“Songbirds are the modern canaries in the coal mines,” Bridget Stutchbury of Toronto’s York University said during an April 2 Parliament Hill presentation.
“I have a simple message – once songbirds are in trouble, we are in trouble.”
She has studied migratory songbirds for several decades and has documented declines in many populations.
In the past 40 years, the wood thrush population has declined by 50 percent, she said.
Read Also
Agriculture ministers agree to AgriStability changes
federal government proposed several months ago to increase the compensation rate from 80 to 90 per cent and double the maximum payment from $3 million to $6 million
The Canada warbler population is less than half what it was.
“If these birds are disappearing, we will be next,” said Stutchbury, a Canada research chair in ecology and conservation biology at York.
Her 2006 book Silence of the Songbirds was short listed for a national award in 2007. It is considered a modern-day sequel to Rachel Carson’s groundbreaking 1962 book Silent Spring.
Stutchbury said the main issue ffecting bird numbers is farm chemicals used in Latin America, where songbirds go for the winter months, flying thousands of kilometres from their Canadian summer nesting areas.
In their winter habitat, chemicals such as terbufos, carbofuran and acephate are used regularly to grow crops. The chemicals can kill or maim songbirds and disrupt their ability to find their way back from winter resting grounds to Canadian breeding grounds, she said.
“This is a serious problem,” Stutchbury said.
“The chemicals they are exposed to make them very vulnerable and reduce their ability to reproduce.”
She said Canada has moved to improve the regulation of some of the older and more toxic chemicals.
A review in progress by the Pest Management Regulatory Agency to re-evaluate older chemical products is a good opportunity to reduce the impact of pesticide use in Canada.
However, she said it is a more difficult problem in Latin America, where chemical use is more widespread and intense and the products often more toxic.
Stutchbury said songbirds face two problems in Central and South America. She showed the audience of MPs, political aides and bureaucrats two maps of South America that showed a decline in tropical forest cover between 1965 and 2005.
“When the forest disappears, the birds are exposed to predators and they lose nesting areas.”
The same maps showed a spread of cultivated land where the forests once stood.
“These agricultural landscapes have a hidden danger for the birds and that hidden danger is pesticides,” she said, showing photographs from Argentina of dead birds lying around a recently sprayed field. They had eaten grasshoppers that had been poisoned by chemicals.
Stutchbury urged the federal government to encourage Latin American countries to strengthen their regulations of pesticide use.
She also said statistics compiled by government agencies in both Canada and the United States show fruit and vegetables imported from Latin America are much more likely to have chemical residues exceeding maxim residue limits than domestically produced product.
Stutchbury said the federal government should lower maximum residue limits.
She also urged consumers to consider organic products, noting sales of organic coffee are rising.
“Coffee drinkers are ahead of vegetable eaters in this,” she said to laughter.
