PARENTAL CARE AND MATING SYSTEM OF THE PRAIRIE VOLE, MICROTUS-OCHROGASTER

1. The mating system of prairie voles (Microtus ochrogaster) was investigated by experimentally manipulating the sexual composition of vole societies, thereby providing each vole with a variety of mating choices. 2. In male-female pairs, both parents appeared to contribute equally to the care of young, with the exception of lactation. Paternal activities included nest and runway construction, food caching, and grooming, retrieving, and brooding the young. 3. Voles in 26 of 27 societies mated monogamously; those in the other group mated polygynously. 4. Nonreproductive voles in the experimental societies generally lived in communal groups. Communal groups are known to occur in field populations of prairie voles, but it is not known if they exist during periods of reproductive activity. 5. We address the questions of the adaptive significance of voles living communally and we consider the relationship between communal voles and dispersing voles in nature. The results of this study were interpreted relative to four mating systems that may be associated with paternal care in mammals. We conclude that M. ochrogaster is basically monogamous; a verbal model is presented for the evolution of monogamy in this species. © 1979 Springer-Verlag.