ARCTIC Relationship between the Onset of Winter and Collared Lemming Abundance
ABSTRACT. Ten periods of high abundance and nine periods of low abundance of collared lemmings (Dicrostonyx richrdsoni) at Churchill, Manitoba, Canada, were determined from 1932 to 1990 using published and unpublished trapping studies. Response functions were used to relate extremes of lemming abund...
| Main Author: | |
|---|---|
| Other Authors: | |
| Format: | Text |
| Language: | English |
| Published: |
1992
|
| Subjects: | |
| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.543.5187 http://pubs.aina.ucalgary.ca/arctic/Arctic46-4-293.pdf |
| Summary: | ABSTRACT. Ten periods of high abundance and nine periods of low abundance of collared lemmings (Dicrostonyx richrdsoni) at Churchill, Manitoba, Canada, were determined from 1932 to 1990 using published and unpublished trapping studies. 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. This indicates that 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. Key words: Churchill, Manitoba, collared lemmings, cycles, freeze-thaw, temperature, precipitation, freezing rain, snow cover RÉSUMÉ. De 1932 ti 1990, on a dktermink 10 pkriodes de forte abondance et 9 @riodes de basse abondance de lemmings it collerette (Dicrostonyx richardsoni) B Churchill (Manitoba), au Canada, en se servant d’ktudes publikes ou inMites sur le pikgeage. On a utilisk les fonctions de repense pour relier les extrhes d’abondance de lemmings B la temperature et aux prkipitations durant les 24 mois prWents. On a trouvk qu’il existait une correspondance intkressante entre les conditions de I’engel automnal et la forte comme la faible abondance des lemmings B collerette. Cela indique que des temp6ratures et des prkipitations nettement diffkrentes de la moyenne peuvent influer sur l’abondance des lemmings B collerette. Au cours du printemps et de l’automne, la frkquence des cycles annuels de gel et dkgel est klevke dans la toundra mkridionale, comme celle qui se trouve B Churchill, ce qui rkvkle que cette region peut &re plus stressante pour |
|---|