The fate of 7,800 pesticide—treated and radiotagged white spruce seeds (Picea glauca (Moench) Voss var. albertiana (S. Brown) Sarg.) was studied under field conditions near Hinton, Alberta, Canada, from 1962 to 1967. Approximately 50% of spring—placed seeds were destroyed by small mammals within 4 months, whereas only 19% or less of winter—placed seeds were lost within a year. From five to six times more seeds germinated following the winter seeding operations than after the first spring seeding test. Calcualted ground seed—eating small—mammal populations varied from 2.0 to 7.4 (average 4.5) animals per acre in spring and from 4.9 to 12.2 (average 8.1) in the fall. Percentages of seeds destroyed were more directly related to time of seeding than to the number of animals present.