Individual study: Predation by red foxes limits recruitment in populations of eastern grey kangaroos
Banks P.B., Newsome A.E. & Dickman C.R. (2000) Predation by red foxes limits recruitment in populations of eastern grey kangaroos. Austral Ecology, 25, 283-291
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
Remove/control non-native mammals
A replicated, controlled study in 1993–1995 in four open grassy sites in the Australian Capital Territory, Australia (Banks et al. 2000) found that controlling invasive red foxes Vulpes vulpes increased eastern grey kangaroo Macropus giganteus population growth rates and juvenile survival. Kangaroo population growth rates were higher in fox control sites than in uncontrolled sites (data reported as statistical model outputs). In sites with fox control the proportion of females with pouch young was similar at the end of pouch emergence (0.87-0.88 females with young) compared to at the beginning (0.78-0.80 females with young), whereas in sites without fox control, the proportion of females with young declined by 50% by the end of the pouch emergence phase (0.55-0.61 females with young) compared to the beginning (0.94-0.97 females with young). Foxes were removed from two sites within Namadgi National Park using 35 g FOXOFF baits (containing 0.3 mg of 1080 poison). Baiting commenced in July 1993 and reduced fox numbers from 2.8–3.4/km to <0.5/km within six months and to almost zero over the following 12 months. Fox numbers in two unbaited sites remained relatively constant (0.8–2/km). Kangaroos were counted in four sites (two with fox control and two without) one hour before dusk from a slow moving car (<5 km/h) along 1.5–2 km transects (400–700 m wide). Surveys were conducted in August, October and December 1993 and then monthly until March 1995. Transects were surveyed twice each survey period.
(Summarised by Ricardo Rocha)