The use of synthetic predator odours to elicit an avoidance response in the roof rat (Rattus rattus)

• Main Author: Burwash, Michael David
• Format: Thesis
• Language: English
• Published: 1996
• Subjects: Rattus rattus
• Online Access: http://hdl.handle.net/2429/5724

I evaluated mongoose (Herpestes auropunctatus) feces and eight synthetic predator odours for eliciting avoidance responses and/or reduced feeding by captured wild roof rats (Rattus rattus). I released individual rats into an open box stainless steel arena, partitioned in half by a wall with an opening allowing passage from one side to the other, as well as access to a covered "safe area". Each half of the arena contained a bowl with a chunk of coconut and a vial of either water or one of the predator odours. I used a video camera to record: 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. Although there were no statistical differences in any one variable, rats displayed trends in response to the predator odours 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 odour which produced the greatest differences in response relative to the control group was DMDIT (red fox (Vulpes vulpes) feces, mustelid anal scent gland). Field trials were conducted to determine whether the synthetic predator odours 3,3- dimethyl-l,2-dithiolane (DMDIT) and £,Z-2,4,5-trimethyl-A3-thiazoline (TMT) were effective at eliciting a behavioural response in wild roof rats (Rattus rattus). The study site was a macadamia nut orchard with a recent history of roof rat feeding damage. The synthetic predator odours were encapsulated in urethane devices which could then be secured to tree branches. Radio telemetry and mark-recapture were used to assess behavioural responses to the predator odours. Mark-recapture data assessed capture numbers, mean male body weight, median distance moved and proportion of capture locations relative to treatment areas. Radio telemetry provided data on home range size (minimum convex polygon), median distance from center of activity and proportion of readings in treated areas. Results from the field trials indicated no treatment effects between pre- and post-treatment weeks or between treatments. Insight was also gained as to the movement patterns of roof rats within an orchard environment. Forestry, Faculty of Graduate