Banning Anti-Coagulant Rodenticides.

29 June 2020

Dear Mayor Fred Haynes and Council,

I am writing on behalf of the Victoria Natural History Society, a community organization that has supported those with an interest in the natural history of our region since 1944 and with approximately 750 members.  We support Councilor Ned Taylor’s and Councilor Colin Plant’s agenda item on July 13th regarding banning Anti-Coagulant Rodenticides.

Owls are perishing due to secondary poisoning from highly toxic Second Generation Anticoagulants (SGAR’s).  Rat poison moves through food webs after a rodent ingests it. In a recent study of

164 owls from western Canada, scientists found that 70% had residues of at least one rodenticide in their livers and at least half of those owls had multiple rodenticides in their system. The necropsy from a Great-horned Owl found in Saanich had three different types of commercial grade anticoagulant rodenticides in its system. Two of them are so potent they are not to be used outdoors. (See link to these reference at end of this letter)

Other wildlife and domestic animals are also at risk of secondary poisoning and many of them go undetected and under reported. As well as the owls in Kings Community Nature Space, we have had anecdotal reports of several otherwise healthy dogs who live in the area or visit the area daily become very ill. Dead or poisoned rats are easy prey for curious pets. BCSPCA and the College of Vets are aware of the owl necropsy reports.

We know there are safer alternatives such as Contrapest and automatic traps ( The District of North Vancouver did an extensive investigative report on the subject of secondary poisoning of wildlife due to rodenticides and voted unanimously this month to ban rodenticides in municipal owned facilities. Their report highlights how using other methods to control rats instead of rodenticides is cheaper in the long run. As a free service, owls eat as many as 1000 rats a year, helping to keep the rodent populations in balance naturally.

We fully support Councilors Ned Taylor and Colin Plant’s motion and applaud them for taking action on this serious issue in our community.

The references mentioned above can be found in the Google drive folder at Photos and references.

Thank you,



Philip Lambert

President, Victoria Natural History Society,