LABORATORY EVALUATION OF PREDATOR ODORS FOR ELICITING AN AVOIDANCE-RESPONSE IN ROOF RATS (RATTUS-RATTUS)

We evaluated eight synthetic predator odors and mongoose (Herpestes au ropunctatus) feces for eliciting avoidance responses and/or reduced fe eding by wild captured Hawaiian roof rats (Rattus rattus). In a bioass ay arena, we recorded: (1) time until each rat entered the arena, (2) time elapsed until first eating bout, (3) time spent in each half of t he arena, (4) number of eating bouts, and (5) consumption. Rats displa yed a response to the predator odors in terms of increased elapsed tim e before initial arena entry and initial eating bout, a lower number o f eating bouts, and less food consumption than in the respective contr ol groups. The odor that produced the greatest differences in response relative to the control group was 3,3-dimethyl-1,2-dithiolane [from r ed fox (Vulpes vulpes) feces and mustelid anal scent gland]. Mongoose fecal odor produced different responses in four of the five variables measured while (E,Z)-2,4,5-trimethyl-Delta(3)-thiazoline (red fox fece s) and 4-mercapto-4-methylpentan-2-one (red fox urine and feces) odors were different from the control group in three of the five variables measured. These laboratory responses suggest that wild Hawaiian roof r ats avoid predator odors.