A Comparison of Maternal Behavior in Three Species of Voles (Microtus pennsylvania, M. pinetorum, and M. ochrogaster) Using a Laboratory System

A system has been developed to describe and compare the maternal behavior of three species of microvine rodents within a naturalistic environment. The apparatus consists of two interconnected Plexiglas-based tables with a peat substrate and hay cover. A pregnant female and her mate are placed within the tables, once the female has shown a thirty percent weight gain and pups can be felt by palpating her abdomen. Maternal behavior, as well as male-female interactions and information on pup physical and behavioral development, are recorded daily for twenty-five days immediately following parturition. Unrestricted observation of female behavior during neonatal, preweaning and post-weaning phases of pup development is possible from below the tables. Preliminary observations indicate that pup behavioral development rate, and male-female social interactions and spatial relationships during the breeding period, differ between the three species. This system provides for ease and clarity of observation of individual microtines, thus combining the best attributes of both field and laboratory studies.