Abstract
To test the hypothesis that adult voles reduce the survival, growth, and maturation rates of young voles, cohorts of young were introduced at 6—week intervals throughout the spring, summer, and fall of 1975 onto an unmanipulated area, a ♂ removal area, and a total removal area. Young survived best on the total removal area but poorly on both other areas. Growth in young ♂ ♂ was directly related to the density of adult ♂ ♂. The weight at which ♀ ♀ attained sexual maturity was directly related to the density of adult ♀ ♀ but not to the density of adult ♂ ♂. Males showed a similar relationship in response to the density of adult ♂ ♂. I conclude that adult ♀ ♀ reduce the survival of young. Further study of ♀—young interactions is necessary to determine the mechanisms involved.