Social Motivation and Residential Style in Prairie and Meadow Voles

The residential style of rodents varies across and within species from colonial to solitary and territorial (1). A mechanism that supports this behavioral distinction might be differential levels of social motivation rather than explicit species-typical social behavior. Accordingly, socially motivated animals learn seeking behavior that leads to a colonial residential pattern and socially unmotivated animals do not learn this behavior and remain solitary. The present experi- ments test this hypothesis by measuring social motivation in a gregarious social species of vole, the prairie vole, and in a solitary species, the meadow vole. Although their explicit social behavior was similar, Prairie voles readily learned to per- form an instrumental response for access to a target vole while meadow voles did not. Neither the estrus status nor the sex of the target affected instrumental responding in either species. In sum, differential social motivation may contribute to distinctive residential patterns in rodents.