A time series and geographical analysis of population dynamics of the red-backed vole in Hokkaido, Japan

Abstract

A time series and geographical analysis of the long term (25-years and 16-years) census data of the red-backed vole, Clethrionomys rufocanus bedfordiae, populations in Hokkaido, Japan was carried out. Eighty seven populations from all over Hokkaido were grouped into the following 4 types according to their flucturation patterns: type A: low density-constant type; type B: medium density-gradual increase type; type C: medium density-wavy change type; type D: high density-large amplitude type. The border between type B and type C was not clear. Although the distribution of the fluctuation types did not show any geographical cline, the high density type (type D) occurred in limited areas where the winter was severe and spring came later and almost all the populations in the Oshima peninsula were the low density type (type A). The most common type of population in Hokkaido, type C, greatly fluctuated from year to year with the maximum density level/the minimum one being over 10. The periodicity of the peak years was not statistically significant, although peaks often occurred at 3 or 4 year intervals. The population grew from spring to autumn in almost all years so that the pattern of the seasonal change was qualitatively constant. The population density levels in spring were not significantly different between peak years and others, while those in autumn were greatly different between them, so that the population growth rates from spring to autumn were variable from year to year. This differential pattern was also found between high and low density areas.

The biology of the voleClethrionomys rufocanus: A review

“…Veda et al (1966) and Ota (1984) provided comprehensive reviews of the Japanese works. More recent studies on this species include Henttonen et al (1977Henttonen et al ( , 1987, Saitoh (1981Saitoh ( , 1987Saitoh ( , 1989Saitoh ( , 1990Saitoh ( , 1991Saitoh ( , 1995, Nakata (1984Nakata ( , 1989, Kawata (1985Kawata ( , 1987Kawata ( , 1988Kawata ( , 1989, Ims (1987aIms ( , b, c, 1988Ims ( , 1989Ims ( , 1990, Yl6nen and Viitala (1987), and Ishibashi et al (1997). The volume edited by Stenseth (1985a) summarized much of what was known, particularly on the basis of the Western literature, at the time about this species and its congeners.…”

The role of vole populations in prevalence of the parasite (Echinococcus multilocularis) in foxes

“…The lowest and highest temperatures in a year usually occur in January and August, respectively. The total precipitation (mm), the maximum snow depth (cm), and the number of days with snow cover over 10 cm in a year are also given as averages during 1985-1992(source: Sapporo District Meteorological Office 1991, 1992 lations usually reach their maximum abundance in fall (Saitoh 1987;Saitoh et al 1998a). Even though most data on infection rates in foxes in Nemuro district came from foxes hunted in Nemuro city (70.2%), the three vole trapping sites in this district did not include Nemuro city.…”

Effects of regime shifts on the population dynamics of the grey-sided vole in Hokkaido, Japan

“…Based on our previous studies, the features of population dynamics of the Hokkaido vole can be summarized as follows (Saitoh 1987, 1998, 1999, 1998, 2002a, 2003, Saitoh et al 1997, 1998, 1999, 2003:…”