Responses of Australian bush rats, Rattus fuscipes, to the odor of introduced Vulpes vulpes

Predator-avoidance behavior of native bush rats (Rattus fuscipes) to an introduced predator (Vulpes vulpes) was investigated by measuring their responses to predator odor. Trapping success of wild bush rats was compared between clean traps and traps scented with fox odor, set along creeks in Namadgi National Park in southeastern Australia. Two experimental, designs were used; the first measured trapping success of clean and scented traps alternating along a trapline through bush rat habitat in winter, spring and summer. The second design offered a choice of clean and scented traps at each trap station and was repeated in spring and summer. Relative trapping successes were analyzed to determine if rats avoided fox odor. Multiple t-tests showed no avoidance responses with similar numbers of captures in clean and fox-scented traps. Consequences of the apparent naivete of bush rats to the odor of an introduced predator are discussed.