Predation by introduced foxes on native bush rats in Australia: do foxes take the doomed surplus?

Published source details Banks P.B. (1999) Predation by introduced foxes on native bush rats in Australia: do foxes take the doomed surplus?. Journal of Applied Ecology, 36, 1063–1071.
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This study is summarised as evidence for the following.

	Action	Category
	Remove/control non-native mammals Action Link

Remove/control non-native mammals

A controlled, before-and-after study in 1993–1995 in four mountain forest sites in the Australian Capital Territory, Australia (Banks 1999) found that after baiting with poison to control invasive red foxes Vulpes vulpes, bush rat Rattus fuscipes numbers did not increase. Bush rat numbers at the end of the study were higher in sites with fox control (11–14 animals) compared to without (6–8 animals). However, in sites with control, bush rat numbers were similar 22 months after fox control began (11-14 animals) compared to immediately beforehand (11-12 animals; results not statistically tested). Four 10–28 km² sites were studied in Namadgi National Park. Fox control started in two sites in July 1993 using 1080 poison bait, and in two sites there was no fox control. Red fox numbers in baited sites were reduced from 2.8–3.4/km to <0.5/km in six months and to almost zero over the following 12 months, while fox density remained stable and approximately five times higher in unbaited sites. Bush rats were monitored on two plots in unbaited sites (>2 km apart) and in one plot in baited sites. In total, two trap lines (25 m apart) of 15 Elliott live traps were set at 10–14 m intervals for three consecutive nights, every two months from June 1993 to March 1995 (6,480 trap nights). Foxes were surveyed using spotlights along transects.

(Summarised by: Ricardo Rocha)