Suchergebnisse

Context Across Australia, feral cat (Felis catus) control and eradication programs are conducted to conserve threatened and vulnerable species. Controlling feral cats effectively at a landscape scale, particularly in remote woodland habitats, remains a significant challenge. Unfortunately, some standard feral cat control methods, such as shooting and cage trapping, require road access. Poison baiting is one of the few methods available to control feral cat populations in remote and inaccessable areas. Aims We aimed to examine the impact of a Curiosity® (Scientec Research PTY LTD, Melbourne, Australia) baiting program on the feral cat population found in continuous woodland habitat of the Dudley Peninsula, on Kangaroo Island, South Australia. Methods The density of cats was monitored using camera traps set up across both treatment and control sites using a before–after control–impact approach. Feral cat density was calculated using a spatially explicit capture–recapture framework. In addition, 14 feral cats were GPS collared at the treatment site, and their status and location, before and after baiting, was monitored. Key results At the treatment site after baiting, feral cat density fell from 1.18 ± 0.51 to 0.58 ± 0.22 cats km−2. In total, 14 feral cats were GPS collared, and of those, eight were detected within the treatment zone during and after bait deployment. Six of those eight cats died shortly after baiting, likely from bait consumption. A new individual cat was detected in the treatment zone within 10 days of baiting, and within 20 days, four new individuals were detected. Both before and after baiting, the number of feral cat detections was highest on roads, suggesting cat recolonisation of baited areas may be assisted by roads. Conclusions Curiosity baiting was found to be an effective method for reducing the density of feral cats in continuous woodland habitats of Kangaroo Island. Roads may act as access routes aiding cat recolonisation. Implications Curiosity baiting programs on Kangaroo Island (and elsewhere) would benefit from incorporating follow-up control, particularly along roads, to target feral cats re-colonising the area.

Abstract
Context Feral cats (Felis catus) are a significant threat to wildlife in Australia and globally. In Australia, densities of feral cats vary across the continent and also between the mainland and offshore islands. Densities on small islands may be at least an order of magnitude higher than those in adjacent mainland areas. To provide cat-free havens for biodiversity, cat-control and eradication programs are increasingly occurring on Australian offshore islands. However, planning such eradications is difficult, particularly on large islands where cat densities could vary considerably.
Aims In the present study, we examined how feral cat densities vary among three habitats on Kangaroo Island, a large Australian offshore island for which feral cat eradication is planned.
Methods Densities were compared among the following three broad habitat types: forest, forest–farmland boundaries and farmland. To detect cats, three remote-camera arrays were deployed in each habitat type, and density around each array was calculated using a spatially explicit capture–recapture framework.
Key results The average feral cat density on Kangaroo Island (0.37 cats km−2) was slightly higher than that on the Australian mainland. Densities varied from 0.06 to 3.27 cats km−2 and were inconsistent within broad habitat types. Densities were highest on farms that had a high availability of macropod and sheep carcasses. The relationship between cat density and the proportion of cleared land in the surrounding area was weak. The total feral cat population of Kangaroo Island was estimated at 1629±661 (mean±s.e.) individuals.
Conclusions Cat densities on Kangaroo Island are highly variable and may be locally affected by factors such as prey and carrion availability.
Implications For cat eradication to be successful, resources must be sufficient to control at least the average cat density (0.37 cats km−2), with additional effort around areas of high carcass availability (where cats are likely to be at a higher density) potentially also being required.