. The Canadian field-naturalist. 1983 Smith: Snowshoe Hare Population Cycles 157. Figure 3. Geographic variation in Snowshoe Hare cycle amphtude, 1931-32 through 1947-48. Stippled shading signifies areas for which data were unavailable. Higher values here represent lower amplitudes; see text for further explanation. (1974) provincial phase lag values for the Canada Lynx over the period 1919 to 1957, a good substantia- tion considering the two different types of data involved and the probability that Bulmer's results are spatially biased by his use of a national norm weighted unevenly by the va
. The Canadian field-naturalist. 1983 Smith: Snowshoe Hare Population Cycles 157. Figure 3. Geographic variation in Snowshoe Hare cycle amphtude, 1931-32 through 1947-48. Stippled shading signifies areas for which data were unavailable. Higher values here represent lower amplitudes; see text for further explanation. (1974) provincial phase lag values for the Canada Lynx over the period 1919 to 1957, a good substantia- tion considering the two different types of data involved and the probability that Bulmer's results are spatially biased by his use of a national norm weighted unevenly by the varying sales volumes of furs for each province. In addition, data of Figure 3 show a trend similar to that subjectively assessed by Adams (1959). Still, it should be emphasized that only limited confi- dence can be attached to the specifics of pattern pro- duced from such a short sampling period, regardless of the great cycle strength occurring in this case. Discussion and Summary Subjective descriptions of the trends visible in Fig- ure 1 accompany the original reports. A full analysis of these and the other data presented here will only be possible within the context of particular spatial- temporal modelling attempts; for the present, how- ever, several general trends can be pointed out. The low amplitude/degree of cycling in south central Canada has been recognized for some time; this is also true for southern British Columbia and parts of the Maritime Provinces. Here, however. Nova Scotia tests as strongly cyclic, and with a large negative phase lag (These patterns were also discovered in the Lynx data analysis in Smith and Davis 1981). A second trend, recognizable in all three summary maps, is a tendency for patterns visible at the southern limits of range to be repeated at the northern limits; thus, phase lag tends to increase, amplitude to decrease, and strength of cycle to diminish geographically south- ward or northward away from a strip extending across central Canada
Size: 1804px × 1384px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorottawafieldnaturalistsclub, bookcentury1900, bookcolle
