Relationship between the onset of winter and collared lemming abundance at Churchill, Manitoba, Canada: 1932-90

Abstract

Ten periods of high abundance and nine periods of low abundance of Dicrostonyx richardsoni were determined from 1932-1990. Response functions were used to relate extremes of lemming abundance to temperature and precipitation in the preceding 24 months. Good correspondence was found between conditions around fall freeze-up and both high and low collared lemming abundance. Thus, far-from-average temperature and precipitation may moderate the abundance of collared lemmings. During spring and fall the southern tundra, such as at Churchill, has a high frequency of annual freeze-thaw cycles, indicating that this area may be more stressful to lemmings than cooler climates with fewer freeze-thaw cycles. -from Author