The City of Duncan has joined North Cowichan with council’s decision on Nov. 15 to ban the use of anticoagulant rodenticides to deal with rodents in all properties owned by the city.
But, like North Cowichan, the city doesn’t have the jurisdiction to ban the use of ACRs overall in Duncan.
Anticoagulant rodenticides kills effectively by interfering with the activation of vitamin K, a critical component in the production of blood clotting factors in the liver, but it’s known that ACRs can be consumed by species other than just rodents, and raptor species like eagles, owls, and hawks are highly susceptible to ACR poisoning when rodents are a primary diet item.
In a report, Duncan’s director of public works and engineering Brian Murphy, said that on June 21, the province announced a temporary ban on most ACRs for 18 months, with exceptions for designated essential services.
Murphy said Duncan’s designated essential service areas include its public works yard on Marchmont Road where aspects of sanitation collection and processing are dealt with, but his report recommended banning the use of ACRs there as well.
He said rodents are attracted to the facility due to the compost materials there and the residues on garbage trucks.
“The city currently utilizes a second-generation anticoagulant rodenticide at the public works facility by a licensed pest control service,” Murphy said.
“There is no rodenticide use at any other city facilities. Under the exemptions to the province’s temporary ban, the province notes that rodents can affect essential services by chewing electrical and data cables, contaminating food storage and spreading diseases.”
Murphy said when North Cowichan banned ACRs, the municipality had raised the significant concerns regarding the potential risks posed to wildlife, as well as domestic animals and human health, through the continued use of the poisons through secondary exposure.
“Several municipalities in B.C. have passed motions or bylaws to ban rodenticide use on all municipal properties since 2020,” Murphy said.
But Murphy acknowledged that safer alternatives to ACRs, including snap traps and live traps, are not considered to be an effective means of controlling rodents, and said that multiple kill repeater traps, like blunt traps, are the only alternative that would offer any degree of effectiveness compared to rodenticides.
But that comes with increased costs, and less effectiveness.
“For the public works department, the pest control service indicates that inspections will need to initially increase from the current frequency of once monthly, at a cost of $120 per month, to service calls every two weeks, at a cost of $215 per month,” Murphy said.
“If there is a spike in rodent activity, the service calls may subsequently need to increase to weekly, at a cost of $430 per month.”
In terms of ongoing debate on the topic, Murphy said there are some concerns that widespread bans of ACRs may result in increasing rodent numbers in urban areas over time and the associated concerns with disease spread and damage.
“Ultimately it should be left to the province to review the issue and those concerns more broadly,” he said.
“For the City of Duncan, it can be anticipated that rodents will indeed become more difficult to control at the public works facility and that the pest control expense will increase correspondingly.”