Bioacoustics of Lasiopodomys brandtii

Movements, Home range and Social organization. Composition of family groups of Brandt's Voles vary seasonally. At the beginning of breeding season, family group usually has one male and one or up to five females. Later, family group also includes yearlings from 2-3 generations. Yearlings born in the first half of the breeding season disperse before achieving sexual maturity, but those born in the second half of the breeding season remain in the family group until next spring. During breeding season, mean size of home range is 2490 m? for males and 1520 m? for females. Home ranges of males marginally overlap with males from other family groups; males aggressively defend core areas of family groups’ home range. At the end of breeding season, males stop defending core areas. At this time, adult females and yearlingsstart storing food for winter and defend an area with radius of ¢.25 m around winter burrow with food storage. Winter groups consist of 4-24 individuals living in one burrow. These groups usually represent large non-dissociate families but sometimes also include non-related individuals. Individuals in wintering groups are tolerant of each other. Summer burrows are relatively simple and have 2-6 entrances and a nest chamber (diameter 10-12 cm) at a depth of 30 cm; total lengths of tunnels are 1-3 m. Winter burrows are much more complex and cover surface area of ¢.7 m* They have 10-15 entrances, a nest chamber (diameter 30-35 cm) at depths of 45-60 cm, several storage chambers with total volume up to 150 dm” and total length of tunnels up to 35 m. Contacts among individuals are accompanied by acoustic communication expressed in quiet or sharp squeals, and during courtship male songs. When in danger, Brandt’s Voles produce alarm calls while standing upright at burrow entrance.