HOME-RANGE AND SOCIAL-ORGANIZATION OF THE SINGING VOLE (MICROTUS-MIURUS)

Intensive live-trapping over four summers revealed that neither popula tion density nor season (early or late growing season) affected the ho me-range size of singing voles. Home-range size increased with body si ze for both sexes, and males generally had larger home ranges than fem ales (average areas of 1,250 and 450 m2 for adult males and females, r espectively). Seasonal patterns of overlap for reproductive animals su ggested that singing voles have a promiscuous mating system and that t erritorial behavior is flexible (males tended to be territorial early in the breeding season and females tended to be territorial late in th e breeding season). The construction of haypiles in August provided wi nter forage with higher protein content and occurred primarily in the home ranges of immature animals, the only cohort found to survive over winter.