Prey selectivity by feral cats at central Australian rock-wallaby colonies

2019 ◽  
Vol 41 (1) ◽  
pp. 132 ◽  
Author(s):  
J. L. Read ◽  
E. Dagg ◽  
K. E. Moseby

Threatened warru, or black-footed rock-wallaby (Petrogale lateralis MacDonnell Ranges race), populations in northern South Australia continued to decline despite baiting for foxes (Vulpes vulpes), which improved their short-term conservation status elsewhere. To investigate whether feral cats (Felis catus) also represent a risk to warru we compared frequencies of prey occurrence in 103 feral cat and 14 fox stomachs shot near warru colonies in northern South Australia during 2001–17 with measures of prey abundance from pitfall trapping and opportunistic searches. We hypothesise that one fresh adult warru kill and the presence of warru remains in four other cats suggests predation by cats on adult and juvenile warru. Small reptiles and invertebrates were the most frequently recorded prey of cats in summer, whereas rodents and small dasyurids were the most frequent prey items in winter. Small mammals, small snakes and pygopodid lizards were over-represented in the diet of cats compared with estimated encounter frequencies, whereas fast-running dragons, knob-tailed geckoes (Nephrurus) and echidnas (Tachyglossus aculeatus) were not recorded from cat stomachs despite being relatively abundant. Rabbits (Oryctolagus cuniculus), rodents and fruits were the most frequently recorded items in fox stomachs. This study reinforces that targeted management of feral cat populations should be considered in concert with control of canids in sustainable recovery programs for warru and other cat-vulnerable species.

2020 ◽  
Vol 47 (8) ◽  
pp. 720
Author(s):  
Alyson M. Stobo-Wilson ◽  
Robert Brandle ◽  
Christopher N. Johnson ◽  
Menna E. Jones

Abstract ContextSignificant resources have been devoted to the control of introduced mesopredators in Australia. However, the control or removal of one pest species, such as, for example, the red fox (Vulpes vulpes), may inadvertently benefit other invasive species, namely feral cats (Felis catus) and rabbits (Oryctolagus cuniculus), potentially jeopardising native-species recovery. AimsTo (1) investigate the impact of a large-scale, long-term fox-baiting program on the abundance of foxes, feral cats and introduced and native prey species in the Flinders Ranges, South Australia, and (2) determine the effectiveness of a short time period of cat removal in immediately reducing feral cat abundance where foxes are absent. MethodsWe conducted an initial camera-trap survey in fox-baited and unbaited sites in the Flinders Ranges, to quantify the impact of fox baiting on the relative abundance of foxes, feral cats and their prey. We then conducted a secondary survey in sites where foxes were absent, following an intensive, but short, time period of cat removal, in which 40 cats were shot and killed. Key resultsNo foxes were detected within baited sites, but were frequently detected in unbaited sites. We found a corresponding and significant increase in several native prey species in fox-baited sites where foxes were absent. Feral cats and rabbits were also more frequently detected within baited sites, but fox baiting did not singularly predict the abundance of either species. Rather, feral cats were less abundant in open habitat where foxes were present (unbaited), and rabbits were more abundant within one predominantly open-habitat site, where foxes were absent (fox-baited). We found no effect of short-term cat removal in reducing the local abundance of feral cats. In both camera-trap surveys, feral cat detections were positively associated with rabbits. ConclusionsLong-term fox baiting was effective in fox removal and was associated with a greater abundance of native and introduced prey species in the Flinders Ranges. To continue to recover and conserve regional biodiversity, effective cat control is required. ImplicationsOur study showed fox removal has likely resulted in the local release of rabbits and an associated increase in cats. Because feral cat abundance seemingly fluctuated with rabbits, we suggest rabbit control may provide an alternative and more effective means to reduce local feral cat populations than short-term removal programs.


2019 ◽  
Vol 46 (5) ◽  
pp. 378 ◽  
Author(s):  
Patrick L. Taggart ◽  
Bronwyn A. Fancourt ◽  
Andrew J. Bengsen ◽  
David E. Peacock ◽  
Patrick Hodgens ◽  
...  

Context Feral cats (Felis catus) impact the health and welfare of wildlife, livestock and humans worldwide. They are particularly damaging where they have been introduced into island countries such as Australia and New Zealand, where native prey species evolved without feline predators. Kangaroo Island, in South Australia, is Australia’s third largest island and supports several threatened and endemic species. Cat densities on Kangaroo Island are thought to be greater than those on the adjacent South Australian mainland, based on one cat density estimate on the island that is higher than most estimates from the mainland. The prevalence of cat-borne disease in cats and sheep is also higher on Kangaroo Island than the mainland, suggesting higher cat densities. A recent continental-scale spatial model of cat density predicted that cat density on Kangaroo Island should be about double that of the adjacent mainland. However, although cats are believed to have severe impacts on some native species on the island, other species that are generally considered vulnerable to cat predation have relatively secure populations on the island compared with the mainland. Aims The present study aimed to compare feral cat abundance between Kangaroo Island and the adjacent South Australian mainland using simultaneous standardised methods. Based on previous findings, we predicted that the relative abundance of feral cats on Kangaroo Island would be approximately double that on the South Australian mainland. Methods Standardised camera trap surveys were used to simultaneously estimate the relative abundance of feral cats on Kangaroo Island and the adjacent South Australian mainland. Survey data were analysed using the Royle–Nichols abundance-induced heterogeneity model to estimate feral cat relative abundance at each site. Key results Cat abundance on the island was estimated to be over 10 times greater than that on the adjacent mainland. Conclusions Consistent with predictions, cat abundance on the island was greater than on the adjacent mainland. However, the magnitude of this difference was much greater than expected. Implications The findings show that the actual densities of cats at local sites can vary substantially from predictions generated by continental-scale models. The study also demonstrates the value of estimating abundance or density simultaneously across sites using standardised methods.


2012 ◽  
Vol 39 (3) ◽  
pp. 258 ◽  
Author(s):  
Andrew J. Bengsen ◽  
John A. Butler ◽  
Pip Masters

Context Effective feral-cat (Felis silvestris catus) management requires a sound understanding of the ways cats use their environment. Key characteristics of landscape use by cats vary widely among different regions and different conditions. Aims The present study aimed to describe the most important characteristics of landscape use by feral cats on a large, human-populated island, and to use this information to guide the development of feral-cat management programs. Methods We used GPS tracking collars to record the movements of 13 feral cats at two sites on Kangaroo Island, South Australia, for between 20 and 106 days. We described home-range extents by using local convex hulls, and derived management suggestions from examination of home-range and movement data. Key results Median feral-cat home range was 5.11 km2, and this did not differ between sexes or sites. Cats at a fragmented pastoral site tended to favour woody vegetation over open paddocks, but habitat preferences were less clear at a bushland site. Cats that preferentially used treelines at the pastoral site were almost twice as likely to be recorded close to a tree-line junction as expected. Conclusions Control programs for feral cats on Kangaroo Island should deploy control devices at a density no less than 1.7 devices km–2. Spatial coverage should be as large as practicable or repeated frequently. Infrequent programs covering small areas can be expected only to provide short-term reductions in cat abundance. Implications The information gained from the present study will contribute to the development of strategic sustained management plans for feral cats on Kangaroo Island. The principles from which we inferred management guidelines are applicable to other regions and species.


2020 ◽  
Vol 47 (8) ◽  
pp. 669
Author(s):  
Rosemary Hohnen ◽  
Karleah Berris ◽  
Pat Hodgens ◽  
Josh Mulvaney ◽  
Brenton Florence ◽  
...  

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.


1985 ◽  
Vol 12 (3) ◽  
pp. 425 ◽  
Author(s):  
NP Brothers ◽  
IJ Skira ◽  
GR Copson

246 feral cats were shot on Macquarie Island, Australia, between Dec. 1976 and Feb. 1981. The sex ratio ( males : females ) was 1:0.8. The percentages of animals with tabby, orange and black coats were 74, 26 and 2 resp. [sic]. Of the 64 orange cats, 56 were males . The breeding season was Oct.-Mar., with a peak in Nov.-Dec. The number of embryos in the 14 pregnant females averaged 4.7 (range = 1-9). The size of the 23 litters that were observed averaged 3 (range = 1-8). Kitten survival to 6 months of age was estimated to be <43%.


Author(s):  
D. W. Minter

Abstract A description is provided for Schizothecium vesticola, a dung-inhabiting fungus. Some information on its associated organisms and substrata, dispersal and transmission, habitats and conservation status is given, along with details of its geographical distribution (Africa (Algeria, Morocco)), North America (Canada (Alberta, British Columbia, Manitoba, Nunavut, Prince Edward Island, Quebec, Saskatchewan, Yukon), Mexico, USA (Alaska, Colorado, Idaho, New York, Utah, Washington, Wyoming), South America (Argentina, Brazil, Chile, Falkland Islands/Malvinas), Arctic Ocean (Denmark (Greenland), Norway (Svalbard)), Asia (Iraq, Pakistan, Russia (Sakhalin Oblast)), Atlantic Ocean (Spain (Canary Islands), St Helena), Australasia (Australia (South Australia, Victoria, Western Australia), New Zealand), Europe (Austria, Belgium, Bulgaria, Denmark (including Faroe Islands), Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy (including Sicily), Netherlands, Norway, Poland, Romania, Russia (Krasnodar Krai, Moscow Oblast, Yaroslavl Oblast), Spain, Sweden, Ukraine, UK)).


Author(s):  
D. W. Minter

Abstract A description is provided for Podospora excentrica. Some information on its associated organisms and substrata, dispersal and transmission, habitats and conservation status is given, along with details of its geographical distribution (South America (Venezuela), Atlantic Ocean (Portugal (Madeira)), Australasia (Australia (New South Wales, South Australia, Victoria, Western Australia)), New Zealand, Europe (Belgium, Denmark, Germany, Ireland, Italy, Netherlands, Spain, Sweden, UK)).


Author(s):  
D. W. Minter

Abstract A description is provided for Nitschkia broomeana, which are found on cracks in bark. Details are given of its hosts, geographical distribution (Gambia, Ghana, Malawi, Sierra Leone, Zimbabwe, USA (Alabama, Florida, Georgia, Idaho, Louisiana, Nebraska, New Jersey, North Carolina, Ohio, Oklahoma, South Carolina, Tennessee and Virginia), Guatemala, Nicaragua, Panama, Argentina, Brazil, Venezuela, China (Beijing, Fujian, Hebei, Hunan, Jiangsu, Sichuan, Yunnan and Zhejiang), India (Andhra Pradesh, Chhattisgarh, Madhya Pradesh and Maharashtra), Japan, South Korea, Pakistan, Sri Lanka, Taiwan, Australia (South Australia), New Zealand, Czech Republic, France, UK, Italy, and Serbia and Montenegro), transmission, diagnostic features and conservation status.


1979 ◽  
Vol 30 (6) ◽  
pp. 741 ◽  
Author(s):  
WG Jones ◽  
KF Walker

The accumulation of iron, manganese, zinc and cadmium by freshwater mussels in the River Murray, South Australia, and their response to changes in environmental iron concentrations are considered. Metal loads varied markedly between individuals from the same population. The variability is accounted for partly by systematic relationships between metal loads and body weight and age, but not sex. The distribution of metals between the major organs is discussed, but the analysis of separate organs showed no advantage for biological monitoring. Comparisons between iron concentrations in river water and in mussels showed no clear correspondence. The study suggests that V. ambiguus may not be a good short-term monitor of iron, but still may have potential as a long-term and site-comparison monitor of metals. once inherent variability is taken into account.


Author(s):  
D. W. Minter

Abstract A description is provided for Geoglossum cookeanum. Some information on its associated organisms and substrata, habitats, dispersal and transmission and conservation status is given, along with details of its geographical distribution (North America (Mexico and USA (Kentucky, Michigan, New Hampshire and Tenesse)), Asia (Georgia, India (Uttarakhand) and China (Guizhou, Heilongjiang, Jilin and Yunnan)), Australasia (Australia (South Australia, Tasmania, Victoria and Western Australia) and New Zealand), Europe (Austria, Belgium, Czech Republic, Denmark, Estonia, Finland, France, Germany, Ireland, Italy, Luxembourg, Netherlands, Norway, Poland, Russia, Slovakia, Spain, Sweden, Switzerland and UK)). No reports of negative economic impacts of this fungus have been found.


Sign in / Sign up

Export Citation Format

Share Document