AGE-RELATED-CHANGES IN ODOR PREFERENCES BY HOUSE MICE LIVING IN SEMINATURAL ENCLOSURES

Changes in odor preferences with age were assessed in house mice inhab iting a series of eight 0.1-ha outdoor enclosures. The most recent cap ture in a live trap was assumed to provide the predominant odor in tha t trap for one week. Data were analyzed for two separate years for fem ales and males and for three age classes within each sex. Initial anal yses confirmed the use of the odor baiting technique; significantly mo re mice than expected entered traps that had captured another mouse in the previous week relative to traps that had not caught a mouse for a t least a week. For female mice two predictions were tested. (1) Young female mice avoid traps with odors from adult males. The findings sup port this prediction. (2) As they mature, female mice will shift their odor preference and enter significantly more traps odorized by adult males. The findings also support this prediction. Two predictions were tested for male mice. (3) Young male mice will avoid odors from adult males. The data do not support this prediction. (4) As they mature, m ales will shift their preference and enter more traps odorized by fema le mice. Some, but not all of the data support this hypothesis.