POPULATION CYCLES AND COLOR PHASE GENETICS OF THE COLORED FOX IN QUEBEC

• Published in: Canadian Journal of Zoology
• Main Author: Butler, L.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1951
• Subjects: Animal Science and Zoology; Ecology, Evolution, Behavior and Systematics; white fox; James Bay
• Online Access: http://dx.doi.org/10.1139/z51-003; http://www.nrcresearchpress.com/doi/pdf/10.1139/z51-003

The pelt collection figures for colored fox in the province of Quebec were examined. The figures for the central and southern part of the province show a typical nine-year cycle. In the northern sections the data show that until 1930 there was a nine-year cycle in colored fox coexisting with a four-year cycle in white fox. After 1930 the four-year and nine-year cycles exist simultaneously with the four-year gradually dominating the scene. In the Upper James Bay region the typical nine-year cycle shows a supplementary peak corresponding with the four-year peak observed in the regions to the north. The coat color phase ratios cannot be explained by monohybrid equilibrium but they are consistent with the view that the population consists of isolates. A partial breakdown of isolate barriers would account for the ratios observed without the necessity of the large unexplained gene frequency changes which occur if panmixia is postulated. Migration causes the breakdown of isolate barriers and this accounts for the sudden shift in gene frequency and explains the long term trends which have resulted in a lower percentage of the silver phase. The degree of isolation changes with the population pressures. The cause of the cycles appears to be resident in the respective area in which the animal breeds. Both the cycle and the color phase data indicate that northward migrations have taken place.