CUES INVOLVED IN RELOCATION OF STRUCK PREY BY RATTLESNAKES, CROTALUS-VIRIDIS-OREGANUS

Following release of an envenomated mouse, a rattlesnake begins a post -strike trailing behavior that allows it to track chemically and to re cover the dispatched prey. The rattlesnake can discriminate the trail of the mouse that it struck from trails of other unstruck mice, sugges ting that the struck mouse produces a chemically unique odor trail. Th e purpose of this study was to determine generally what those chemical cues might be and what emphasis the rattlesnake might give to each du ring post-strike trailing. Taking advantage of venomoid (venomless) ra ttlesnakes, four experiments were performed in which we examined the a bility of rattlesnakes to discriminate trails of mice receiving fang p unctures (but no venom), mice artificially struck by hand (no venom), different individual mouse scents, and the effects of venom on post-st rike trailing ability. We found that fang puncture alone was sufficien t to produce a distinctive odor trail, but that this was subordinate t o the distinctiveness of individual mice odors; envenomated mice produ ced the most distinctive trail. Our results indicate that alone the me chanical effects of fang penetration of the integument produce a chemi cal uniqueness in the mouse, but that can be overridden by mouse odor and venom effects. Thus, rattlesnakes biting mice have available ranke d odors unique to the struck mouse: venom > mouse odor > fang puncture .