Communal nesting in prairie voles (Microtus ochrogaster): formation, composition, and persistence of communal groups
We describe factors related to the formation, composition, and persistence of communal groups in the prairie vole (Microtus ochrogaster). Communal groups formed by the addition of philopatric offspring and unrelated adults to male – female pair and single-female breeding units. Although unrelated adults did not join a group until at least two philopatric offspring 30 days of age were present, there was no relationship between the presence of reproductively active philopatric offspring of the opposite sex and joining of unrelated adults. Most adults that joined a group were reproductive when they joined. Reproductive activation of philopatric offspring was not related to the joining of unrelated adults. During the breeding period all communal groups included 1 or more reproductive adults of each sex; in at least 75% of the groups, 2 or more adults of each sex were reproductive. There was no relationship between low temperature, snow cover, or population density and formation of communal groups. Dissolution of communal groups was not related to reproductive activation of residents.