U.S. Department of Agriculture: Animal and Plant Health Inspection Service


Date of this Version



Published in Journal of Chemical Ecology, Vol. 24, No. 1, 1998. © 1998 Plenum Publishing Corporation. Permission to use.


We evaluated eight synthetic predator odors and mongoose (Herpestes auropunctatus) feces for eliciting avoidance responses and/or reduced feeding by wild captured Hawaiian roof rats (Rattus rattus). In a bioassay 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 the arena, (4) number of eating bouts, and (5) consumption. Rats displayed a response to the predator odors in terms of increased elapsed time before initial arena entry and initial eating bout, a lower number of eating bouts, and less food consumption than in the respective control groups. The odor that produced the greatest differences in response relative to the control group was 3,3-dimethyl-l ,2-dithiolane [from red 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-A3-thiazoIine (red fox feces) 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 rats avoid predator odors.