Strychnine has recently been made available in Canada under an emergency registration program for the control of Richardson's ground squirrels. From 2007 to 2009, we tested the control efficacy of this poison using >1-year-old and newly produced strychnine on hulless oats, canary seed, and alfalfa pellets. Newly produced 2% liquid strychnine, mixed with hulless oats to formulate 0.4% strychnine freshly mixed baits, controlled ≥70% of adult and juvenile ground squirrels in spring and summer. Other types of strychnine baits were not as reliable from one season to the other. At 0.2% concentration, strychnine-treated oats were relatively inefficient. When >1 year old, the control efficacy of strychnine baits dropped significantly. Independent of the age of the product, strychnine killed non-target animals. This paper recommends a series of measures to ensure quality control and greater selectivity.

During a study of Richardson's Ground Squirrel (Spermophilus richardsonii) populations in southern Saskatchewan, we captured one adult female with a partially prolapsed uterus. This is the first known case of uterine prolapse in a Richardson's Ground Squirrel.

The Western Harvest Mouse (Reithrodontomys megalotis) is rare in Canada, and its distribution is believed to be restricted to south-central British Columbia and southeastern Alberta. Between 2008 and 2010, we identified Western Harvest Mouse hairs in 71 of 1424 scats (5%) of Red Fox (Vulpes vulpes), Coyote (Canis latrans), American Badger (Taxidea taxus), and Long-tailed Weasel (Mustela frenata) collected in southwestern Saskatchewan. The presence of Western Harvest Mouse was confirmed at the same latitude as populations reported in Alberta and British Columbia, in scats collected in or nearby grasslands. This is the first time that the presence of the Western Harvest Mouse has been confirmed in Saskatchewan.