A note on aberrant pelage colors in a wild population of the gray red-backed vole Clethrionomys rufocanus bedfordiae in Hokkaido

Abstract

The pelage of adult gray red-backed voles Clethrionomys rufocanus bedfordiae (Rodentia, Arvicolinae) in Hokkaido is usually red-brown or black on the dorsum and ivory or gray-ivory on the side-venter (Fig. 1a; Ota 1984; Nakata et al. 1989). However, pelage aberrations have been observed on several occasions in natural populations of C. rufocanus bedfordiae (Aizawa and Makino 1938; Fujimaki 1974; Murakawa 1986; Miyatsu et al. 1988; Takahashi 1988; Nakata et al. 1989). Although pelage color aberrations of this vole have been known of since 1938, there have been no records of several individuals with different pelage color aberrations being captured at one time from a single locality (Nakata et al. 1989). In July 2003, however, three specimens were collected from a locality in Hokkaido, these three were aberrant types with light brown buff pelage and partially white pelage. Ecological and genetic perspectives on these aberrations are expressed.