The federal government is taking extra steps to find out if Canadians are still OK with killing wildlife in what one scientist calls "one of the worst ways to die on earth."
The Pest Management Review Agency has extended public consultations into whether it should consider cruelty before licensing poisons used to control large predators such as wolves.
The most common of the three toxins under consideration is strychnine. One of Canada's largest users is the government of Alberta, which has used it to poison hundreds of wolves to help caribou herds survive in ranges heavily disrupted by industrial development.
"The use of pesticides to control large predators and the unintended effects on non-target animals is a growing concern among Canadians," says the agency's website.
Within 20 minutes of being dosed by strychnine, muscles start to convulse. The convulsions increase in intensity and frequency until the backbone arches and the animal asphyxiates or dies of exhaustion.
"Strychnine is one of the worst ways to die on earth in terms of pain and in terms of being conscious and aware," said Ryan Brook, a professor in the University of Saskatchewan's agriculture department.
"We have to do better. If you tried, I don't think you could find a worse way to do it."
Last fall, the advocacy group Wolf Awareness released a letter to the federal government calling strychnine and two other compounds inhumane. The letter was signed by 50 scientists and animal-welfare advocates from across Canada and three countries.
It's time Canada modernized its thinking on predator control, said Barbara Cartwright of Humane Canada, the national voice for humane societies and SPCAs.
"There's a great need to overhaul our wildlife management," she said.
"It has to be targeted and effective. There also needs to be — and this is a growing concern around the world — minimized animal welfare harms."
Strychnine opponents say the poison meets none of those standards.
Wolf Awareness has released documents showing that — along with 1,200 wolves killed by various means in Alberta since 2005 — at least 257 other animals have been poisoned, including 44 foxes and a grizzly bear.
Those numbers are likely to be conservative, said Sadie Parr of Wolf Awareness, because strychnine remains in the food web.
"Anything that consumes a poison carcass also suffers that same horrendous fate prior to death."
Many scientists doubt poisoning actually reduces wolves.
"You kill a dominant wolf, the pack splits, sometimes up to three or four times," said biologist Gilbert Proulx. "Then you're faced with four litters the following year instead of one."
Alberta government biologists say the wolf cull, which also uses aerial gunning, has preserved caribou on a landscape heavily affected by energy development and forestry.
Alberta Environment spokesman Matt Dykstra points out farmers also use strychnine to control rodents — although at a much lower dose that dwarfs the amount used against wolves.
Dykstra wonders how humaneness could even be measured.
"Humaneness is not something that can be defined with any degree of accuracy," he said.
The federal agency is using a definition created by the Australian Royal Society for the Prevention of Cruelty to Animals. It refers to "feasible control programs and techniques that avoid or minimize pain, suffering and distress to target and non-target animals."
Proulx said strychnine is no longer used to control predators in most Commonwealth and European countries or most U.S. states.
Parr acknowledges that hard choices sometimes have to be made on busy landscapes. But some decisions, she said, go beyond science.
"Gone is the day and age when we can do whatever we want to whatever we want," she said. "This is a conservation dilemma but it's also a moral dilemma."
— Follow Bob Weber on Twitter at @row1960
Bob Weber, The Canadian Press