District of North Vancouver will research alternative types of traps and controls for rodents because of the increasing number of owls being killed by secondary rodenticide poisoning.
The district also plans to create a one-year pilot project on alternative rodent control methods at certain facilities. The report is expected to be before council in 2020.
Staff informed council this summer that they received several calls from people who found owls and other raptors dead, later confirmed to have been killed by eating rats infested with poison. Other animals are also dying of secondary poisoning.
“A number of local owls have been confirmed, via toxicity testing, to have ingested fatal amounts of rodenticide. There is additional data that documents the presence of rodenticide occurring in other higher-order predators such as weasels and coyotes as well as scavenger species like birds and squirrels,” the staff said.
DNV says it is now discussing the use of rodenticide and bait traps with its partner organisations, such as the North Vancouver Recreation and Culture Commission, which has a number of facilities adjacent to green belts and wildlife corridors. NVRC currently has a contractor that uses rodenticide bait traps at six sites within the DNV.
The recreation commission has obtained cost estimates for alternative methods.
“Switching to mechanical snap traps or other methodology does add cost due to more labour associated with inspection and maintenance of deployed traps. Rodenticide bait traps have been the preferred rodent control method, mainly due to what was thought to be their effectiveness and lower cost. However more local research on the effectiveness of alternative methods compared to bait traps is needed,” the staff told council.
Staff also conducted an informal survey of a number of local pest control companies and determined that all the companies surveyed used rodenticide bait traps to some degree. Although some companies limit the amount of poisoned bait, none of them appeared to keep track of the amount of rodenticide being deployed into the environment.
Community activist Elise Roberts says DNV should create a new bylaw to end or at least limit the use of second-generation rodenticides in the community. “And that means at any building, community centre, shopping mall, strata,” she says.
Ever since DNV resident Roberts found a dead owl besides Blueridge Creek, she has been actively researching the issue, and has contacted DNV Parks, Health Canada and provincial authorities. She also contacted Sandi Lee, wildlife ecotoxicology technician, at Environment Canada, who told her the agency collected 25 raptor carcasses from North Vancouver between 2013 and 2018.
They were found in Cleveland Park, North and Lower Lonsdale, Central and Upper Lynn, Lower Capilano, Carisbroke and Pemberton Heights.
A post-mortem analysis of 18 carcasses revealed that 10 had detectable liver residues that included rodenticide. Of those 10 samples, eight had total liver residues that suggested a “significant” likelihood of toxicosis. Lee is now working on analysing more recent data from North Shore and Metro Vancouver.
Katharine Fremlin, a doctoral student at the Department of Biological Sciences at SFU, did an ecological risk assessment of pesticide use on owls in DNV, especially potential risks from the recreation centres. She found that owls that eventually died due to injuries or sickness were typically in close proximity to green spaces, public parks or riparian areas.
Many of the owls were within one to two km of recreation and community centers, she said.
“My findings likely underestimated the overall risk of rat poisons to owls on the North Shore as bait boxes with rat poisons are commonly used across North Vancouver at commercial and residential properties – and I only looked at the potential risk from the recreation centers,” she said.
DNV spokesperson Courtenay Rannards said the district was in the process of researching and compiling the findings and would inform the community once the project was complete.
Elise Roberts is right in my opinion. The second generation rodenticides are known to be toxic to non-target species, in particular predators like owls, eagles and cats. Living so close to nature we have a responsibilty to not kill off small predator species within our still natural ecosystem on the North Shore. More importantly, first generation rodenticides like Warfarin still work here and were designed to not kill non-target species. In places like New York the rats developed resistance to Warfarin which is why the more damaging second generation rodenticides were developed. I know in my neighbourhood, first generation Warfarin still works and is available. Eventually it will likely become ineffective but for now we can and should be sticking with the rodenticides that are not going to kill the predators that find and eat the dead rats. Those predators like owls, eagles and cats are helping us control and clean up the rat population as well as being a cherished part of our ecosystem.
about time it was banned in the DNV at least…My Cat was poisoned by a dead rat that itself had being poisoned..only quick intervention and a large amount money saved her…
Elise Roberts is a wonderful advocate for our planet! Thank you Elise for all the work you have done!
I just came across this article after researching current laws and regulations surrounding the use of rat poison in residential settings because i just discovered several black bait boxes in the backyard of our new not so nice neighbours.
We live directly under the greenbelt in north van very close to grouse mountain and there is nothing but forest behind us.
One of these poison boxes is just a few feet from our property line and abut 20 feet from our cat door.
This is a brand new house, they just moved in a month ago and there is no way they have a rat infestation (and they probably never will since the house is a concrete fortress that they selfishly blasted massive amounts of bedrock with explosives to nestle it into the mountain. They caused a lot of damage as a result, but that’s a whole other story)
We literally live right in the forest and they are needlessly poisoning rats, squirrels, chipmunks and everything else that eats them including neighbourhood cats and wild birds of prey. There are so many owls in our backyard and all over this area and you can hear them talk to each other almost every night.
It completely baffles me how this is even legal, or is it?? I do not understand how both these incompetent new homeowners and the pest control company they hired would feel it is ok to move into a new area bordering the wilderness and start to poison wild animals in their own natural habitat.
Im sure the rat population is in the millions up these north shore mountains, there always has been rats and always will be rats. In my opinion these people should be arrested, fined and publicly shamed as animal abusers because they are intentionally poisoning and killing wildlife in their own natural habitat for no reason at all other than they probably saw a rat walk by on their outdoor cctv footage.
They put the black boxes immediately below the cameras, probably to see what they kill. i will start making calls in the morning and if i have no luck getting them removed i will do it myself.