Mating system and reproductive success in a spring population of the red-backed vole, Clethrionomys rufocanus bedfordiae.

Most adult females copulated at post-partum estrus. Birth synchrony was observed in both the field and laboratory. Females occupied exclusive home ranges; males usually had overlapping home ranges that often enclosed those of several females. Multiple paternity was rare in this population. No male whose home range did not overlap with a female's range sired any of her offspring; but the degree of the overlap did not always affect copulatory success. No male successfully copulated with 2 females who had synchronized their parturitions. The body weight, testis weight, seminal vesicle weight, adrenal gland weight, flank gland size, and root ratio (age) of 10 successful males were compared with those of all captured adult males. Strong evidence for mate selection in these six male traits could not be found, although some differences in the means of flank gland size and seminal vesicle weight between 10 successful males and the population were observed.-from Author