Evaluation of Alternatives to Strychnine

Resolution 1-19, 3-21, 4-21, 11-23

2022 research in Saskatchewan and Alberta shows there are effective alternatives to Strychnine for Richardson Ground Squirrel (RGS) control. The study was conducted on grasslands and pastures with high populations of RGS in the MD of Willow Creek in Alberta and the Rural Municipality of Swift Current in Saskatchewan.

The study tested two anticoagulant products and two Zinc Phosphide products.

Product compared with 2% StrychnineAnticoagulant Zinc PhosphideAB site resultsSK site results$/Acre for one application
Rozol RTUXNo observed differenceLess effective14.73
Ramik GreenXNo observed differenceLess effective10.60
Burrow Oat BaitXNo observed differenceSame as Strychnine4.54
ZP Rodent Oat Bait AGXNo observed differenceSame as Strychnine 8.80
Cost of Strychnine estimated at $12.97.

Anticoagulants vs Zinc Phosphide

Rozol RTU and Ramik Green are by far the most expensive products. For this study they applied the products twice, where the Zinc Phosphide products were effective with just one treatment.

Intake was best for all products when available just when the RGSs are emerging from over wintering but before the pastures green up. Once green forage is available they are less interested in the baits.

Green forage, especially legumes, provide a significant source of vitamin K which is an antidote to the anticoagulant products (Rozol RTU and Ramik Green). There are no antidotes for the Zinc Phosphide products.


This study indicated that the Zinc Phosphide products can be as effective as 2% Strychnine at a much lower cost. Timing of application is key to success with any product but especially with the more expensive anticoagulant types.

Resources for further information

The Chinook Applied Research Association hosted three webinars this spring to address RGS control that were very popular with producers:

  1. Dr. James Tansey, “An evaluation of some alternatives to strychnine” (April 6 2023)
  2. Brad Downey, “Benefits of natural control agents, hawk pole design/use, & encouraging birds of prey to nest” (April 13, 2023)
  3. Andrea Sawatzky, “What happened to strychnine?” (April 20, 2023)

The Saskatchewan Ministry of Agriculture Crop Production News article summarizing the research study is available online:

Alternatives to Strychnine, Crop Production News June 2022

The full research detail can be found on the Saskatchewan Ministry of Agriculture website at the following link: Control of Richardson Ground Squirrel

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