New federal restrictions on rodenticide sales should reduce incidents of accidental poisonings, including of threatened birds of prey.
"We're hoping there will be fewer incidences of poisoned rats going outside and then getting eaten by wildlife," said Sofi Hindmarch, an independent contract biologist who did her master's thesis on barn owls. "It's an attempt to contain where the poison is going."
A 2009 Environment Canada study of the livers of 164 barn, barred and great horned owls from B.C. and Yukon found evidence of at least one anticoagulant rodenticide in 70 per cent of cases. Barn owls are a threatened species in B.C.
Of those, more than 41 per cent contained more than one rodenticide, most often the second-generation poisons, including bromadiolone, which are now restricted to indoor use or against the outside walls of dwellings, including farm buildings and restaurants.
Health Canada explained in a news release that anticoagulant rodenti-cides fall into two categories: first-generation products (chlorophaci-none, diphacinone, warfarin) and second-generation products (brodifa-coum, bromadiolone, difethialone).
Under new federal rules, sales of highly toxic second-generation anticoagulant rodenticides will be restricted to professionals. Public retail sales of less-potent, first-generation poisons must include bait stations to further reduce unintended poisonings.
Manufacturers were permitted to sell existing rodenticide products until Dec. 31, 2012. All products distributed after that date at the manufacturer level must bear new label requirements.
Older rodenticides currently on the market may be sold by retailers until Dec. 31, 2013, and can continue to be used according to current label directions until Dec. 31, 2016.
James Nicol, a manager with Burnaby's Care Pest and Wildlife Control, encouraged the public to use traps as an effective and environmentally friendlier alternative.
"When it comes to rats and mice, traps are probably the best," he said.
Traps ensure rodents don't die in walls and they work faster than baits, which can take many days to kill a rodent. They also ensure the rodent does not wander off to be consumed by pets or wildlife.
Nicol recommends people place traps alongside walls where rodents tend to travel, close to where they find droppings, or inside a bait station for added safety.
"Under your stove, behind your fridge, maybe a storage room. Places that are undisturbed."
Nicol uses "chocolate frosting" as trap bait, although peanut butter also works well.
lpynn@vancouversun.com