Wildlife Research Wildlife Research Society
Ecology, management and conservation in natural and modified habitats

Control of feral cats for nature conservation. IV. Population dynamics and morphological attributes of feral cats at Shark Bay, Western Australia

Jeff Short A B and Bruce Turner A

A CSIRO Sustainable Ecosystems, Private Bag 5, Wembley, WA 6913, Australia.

B Present address: Wildlife Research and Management, PO Box 1360, Kalamunda, WA 6926, Australia. Email: jeff.short@optusnet.com.au

Wildlife Research 32(6) 489-501 http://dx.doi.org/10.1071/WR04102
Submitted: 29 October 2004  Accepted: 19 July 2005   Published: 18 October 2005


The dynamics of feral cats (Felis catus) were assessed at Shark Bay at two adjoining sites subject to differing intensities of predator control. The Heirisson Prong conservation reserve (12 km2) was fenced to exclude predators and was subject to intensive control actions, while a portion of the adjoining Carrarang pastoral lease (60 km2) was subject to a lesser level of control. Foxes (Vulpes vulpes) were largely absent at both sites owing to effective control. Densities of cats were highly variable over time, showing strong annual fluctuations over 14 years of records Three independent estimates of peak density were made, varying between 1.5 and 2.8 km–2. Rate of increase was assessed as 0.98 on the pastoral lease and 0.99 on the conservation reserve (to give an approximate doubling of the population every 8.5 months). A logistic model, with K = 1.5 km–2 and r of 0.98, gave a maximum sustained yield of 0.37 cats km–2 year–1 and a harvest rate of >0.6 cats km–2 year–1 for their elimination in 5 years or less (for K = 2.8 km–2, these values increase to 0.69 and >1.05 km–2 year–1 respectively). Harvest outcomes at both sites were consistent with these models. However, the effort required to maintain a given offtake rate increased 6-fold at low cat densities and offtake by trapping as a function of cat density took the form of a Type 3 functional response. The functional response for cat trapping (the offtake with constant effort per unit time) overlaid against the curve of cat productivity suggested a stable equilibrium point at low cat densities (0.07–0.13 cats km–2). Hence, trapping effort needed to be greatly intensified at low cat densities and/or augmented by other methods of control to eradicate cats from the closed system of the reserve. The strongly male-biased sex ratio of captures at the barrier fence suggested high levels of reinvasion from beyond the harvested area of the pastoral lease and this made effective control in this open system difficult.


Abbott I. 2002 Origin and spread of the cat, Felis catus, on mainland Australia, with a discussion of the magnitude of its early impact on native fauna. Wildlife Research 29 51 74 DOI

Algar D. Kinnear J. E. 1992 Cyanide baiting to sample fox populations and measure changes in relative abundance. Bureau of Rural Resources Proceedings 11 135 138

Algar D. Smith R. 1998 Approaching Eden. Landscope 13 28 34

Apps P. J. 1986 Home ranges of feral cats on Dassen Island. Journal of Mammalogy 67 199 200

Barlow N. D. Norbury G. L. 2001 A simple model for ferret population dynamics and control in semi-arid New Zealand habitats. Wildlife Research 28 87 94

Bester M. N. Bloomer J. P. Bartlett P. A. Muller D. D. van Rooyen M. Buchner H. 2000 Final eradication of feral cats from sub-Antarctic Marion Island, southern Indian Ocean. South African Journal of Wildlife Research 30 53 57

Bloomer J. P. Bester M. N. 1992 Control of feral cats on sub-Antarctic Marion Island, Indian Ocean. Biological Conservation 60 211 219

Brothers N. P. Skira I. J. Copson G. R. 1985 Biology of the feral cat, Felis catus (L.), on Macquarie Island. Australian Wildlife Research 12 425 436 DOI

Burbidge A. A. Manly B. J. F. 2002 Mammal extinctions on Australian islands: causes and conservation implications. Journal of Biogeography 29 465 473 DOI

Calver M. C. King D. R. Risbey D. A. Short J. C. Twigg L. E. 1998 Ecological blunders and conservation: the impact of introduced foxes and cats on Australian native fauna. Journal of Biological Education 32 67 72

Catling P. C. 1988 Similarities and contrasts in the diets of foxes, Vulpes vulpes, and cats, Felis catus, relative to fluctuating prey populations and drought. Australian Wildlife Research 15 307 317

Case T. J. (2000). ‘An Illustrated Guide to Theoretical Ecology.’ (Oxford University Press: New York.)

Caughley G. (1977). ‘Analysis of Vertebrate Populations.’ (John Wiley and Sons: Brisbane.)

Caughley G. Krebs C. J. 1983 Are big mammals simply little mammals writ large? Oecologia 59 7 17 DOI

Choquenot D. (1992). The outsiders: competition between introduced herbivores and domestic stock in rangeland grazing systems. In ‘Australian Rangelands in a Changing Environment, 7th Biennial Conference of the Australian Rangeland Society’. pp. 106–116. (Australian Rangeland Society: Cobar, NSW.)

Christensen P. , and Burrows N. L. (1994). Project Desert Dreaming: the reintroduction of mammals to the Gibson Desert, Western Australia. In ‘Reintroduction Biology of Australian and New Zealand Fauna’. (Ed. M. Serena.) pp 199–207. (Surrey Beatty: Sydney.)

Coman B. J. 1986 Control of feral cats and foxes in a rabies exercise. Australian Veterinary Journal 63 8

Courchamp F. Langlais M. Sugihara G. 1999 Cats protecting birds: modelling the mesopredator release effect. Journal of Animal Ecology 68 282 292

Derenne P. 1976 Notes sur la biologie du chat haret de Kerguelen. Mammalia 40 531 595

Domm S. Messersmith J. 1990 Feral cat eradication on a Barrier Reef island, Australia. Atoll Research Bulletin 338 1 4

Edwards G. P. de Preu N. Shakeshaft B. J. Crealy I. V. Paltridge R. M. 2001 Home range and movements of male feral cats (Felis catus) in a semi-arid woodland environment in central Australia. Austral Ecology 26 93 1001

Holling C. S. 1959 The components of predation as revealed by a study of small mammal predation of the European pine sawfly. Canadian Entomologist 91 293 320

Horsup A. Evans M. 1993 Predation by feral cats, Felis catus, on an endangered marsupial, the bridled nailtail wallaby, Onychogalea fraenata. Australian Mammalogy 16 83 84

Izawa M. Ono Y. 1986 Mother–offspring relationship in the feral cat population. Journal of the Mammalogical Society of Japan 11 27 34

Izawa M. Doi T. Ono Y. 1982 Grouping patterns of feral cats (Felis catus) living on a small island in Japan. Japanese Journal of Ecology. 32 373 382

Jones E. 1977 Ecology of the feral cat, Felis catus (L.), (Carnivora: Felidae) on Macquarie Island. Australian Wildlife Research 4 249 262

Jones E. Coman B. J. 1982 a Ecology of the feral cat, Felis catus (L.), in south-eastern Australia. II. Reproduction. Australian Wildlife Research 9 111 119 DOI

Jones E. Coman B. J. 1982 b Ecology of the feral cat, Felis catus (L.), in south-eastern Australia. III. Home ranges and population ecology in semiarid north-west Victoria. Australian Wildlife Research 9 409 420 DOI

Jones E. Horton B. J. 1984 Gene frequencies and body weights of feral cats, Felis catus (L.), from five Australian localities and from Macquarie Island. Australian Journal of Zoology 32 231 237 DOI

Konecny M. J. 1987 Home range and activity patterns of feral house cats in the Galapagos Islands. Oikos 50 17 23

Krebs C. J. Singleton G. R. 1993 Indices of condition for small mammals. Australian Journal of Zoology 41 317 323

Liberg O. , and Sandell M. (1988). Spatial organisation and reproductive tactics in the domestic cat and other felids. In ‘The Domestic Cat: the Biology of its Behaviour’. (Eds D. C. Turner and P. Bateson.) pp 83–98. (Cambridge University Press: Cambridge.)

Merton D. (1977). Controlling introduced predators and competitors on islands. In ‘Endangered Birds. Management Techniques for Preserving Threatened Species’. (Ed. S. A. Temple.) pp. 121–128. (University of Wisconsin Press: Madison, WI.)

Molsher R. L. 2001 Trapping and demographics of feral cats (Felis catus) in central New South Wales. Wildlife Research 28 631 636 DOI

Morris K. D. , Sims C. , Himbeck K. , Christensen P. , Sercombe N. , Ward B. , and Noakes N. (in press). Project Eden. In ‘Western Shield Review’. Conservation Science. (Department of Conservation and Land Management: Perth.)

Natoli E. 1985 Spacing pattern in a colony of urban stray cats (Felis catus L.) in the historic centre of Rome. Applied Animal Behaviour Science 14 289 304 DOI

Newsome A. E. (1991). Feral cats: an overview. In ‘The Impact of Cats on Native Wildlife’. (Ed. C. Potter.) pp 7–13. (Australian National Parks and Wildlife Service: Canberra.)

Newsome A. E. (1995). Cat Felis catus Linnaeus, 1758. In ‘The Mammals of Australia’. (Ed. R. Strahan.) pp. 700–702. (Australian Museum / Reed Books: Sydney.)

Noy-Meir I. 1975 Stability of grazing systems: an application of predator–prey graphs. Journal of Ecology 63 459 481

Pech R. P. Hood G. R. 1998 Foxes, rabbits, alternative prey and rabbit calicivirus disease: consequences of a new biological control agent for an outbreaking species in Australia. Journal of Applied Ecology 35 434 453

Pech R. P. Sinclair A. R. E. Newsome A. E. Catling P. C. 1992 Limits to predator regulation of rabbits in Australia: evidence from predator-removal experiments. Oecologia 89 102 112 DOI

Priddel D. Wheeler R. 2004 An experimental translocation of brush-tailed bettongs (Bettongia penicillata) to western New South Wales. Wildlife Research 31 421 432 DOI

Rauzon M. J. 1985 Feral cats on Jarvis Island: their effects and their eradication. Atoll Research Bulletin 282 1 32

Read J. L. 2003 Are miners the bunnies or the bilbies of the rangelands? Rangeland Journal 25 172 182

Read J. Bowen Z. 2001 Population dynamics, diet and aspects of the biology of feral cats and foxes in arid South Australia. Wildlife Research 28 195 203 DOI

Richards J. D. Short J. 2003 Reintroduction and establishment of the western barred bandicoot Perameles bougainville (Marsupialia: Peramelidae) at Shark Bay, Western Australia. Biological Conservation 109 181 195 DOI

Ricklefs R. E. (1980). ‘Ecology.’ 2nd edn. (Nelson: Middlesex, UK.)

Risbey D. A. Calver M. C. Short J. 1999 The impact of cats and foxes on the small vertebrate fauna of Heirisson Prong, Western Australia. I. Exploring potential impact using diet analysis. Wildlife Research 26 621 630

Risbey D. A. Calver M. C. Short J. Bradley J. S. Wright I. W. 2000 The impact of cats and foxes on the small vertebrate fauna of Heirisson Prong, Western Australia. II. A field experiment. Wildlife Research 27 223 235

Rogers Q. R. , Baker D. H. , Hayes K. C. , Kendall P. T. , and Morris J. G. (1986). ‘Nutrient Requirements of Cats.’ (National Academy Press: Washington, DC.)

Short J. (1999). Decline and recovery of Australian mammals, with particular emphasis on the burrowing bettong, Bettongia lesueur. Ph.D. Thesis, Murdoch University, Perth.

Short J. Turner B. 2000 Reintroduction of the burrowing bettong Bettongia lesueur (Marsupialia: Potoroidae) to mainland Australia. Biological Conservation 96 185 196 DOI

Short J. , Turner B. , Parker S. , and Twiss J. (1994). Reintroduction of endangered mammals to mainland Shark Bay: a progress report. In ‘Reintroduction Biology of Australian and New Zealand Fauna’. (Ed. M. Serena.) pp 183–188. (Surrey Beatty: Sydney.)

Short J. Turner B. Risbey D. A. Carnamah R. 1997 Control of feral cats for nature conservation. II. Population reduction by poisoning. Wildlife Research 24 703 714 DOI

Short J. Turner B. Risbey D. A. 2002 Control of feral cats for nature conservation. III. Trapping. Wildlife Research 29 475 487 DOI

Sinclair A. R. E. (1996). Mammal populations: fluctuation, regulation, life history theory and their implications for conservation. In ‘Frontiers of Population Ecology’. (Ed. R. B. Floyd, A. W. Sheppard and P. J. De Barro.) pp 127–154. (CSIRO Publishing: Melbourne.)

Spencer P. B. S. 1991 Evidence of predation by a feral cat Felis catus (Carnivora: Felidae) on an isolated rock-wallaby colony in tropical Queensland. Australian Mammalogy 14 143 144

van Aarde R. J. 1984 Population biology and the control of feral cats on Marion Island. Acta Zoologica Fennica 172 107 110

van Rensburg P. J. J. 1986 Control of the Marion Island cat (Felis catus) population: why and how. Suid-Afrikaanse Tydskrif vir Navorsing in Antarktika 16 110 112

van Rensburg P. J. J. Skinner J. D. van Aarde R. J. 1987 Effects of feline panleucopaenia on the population characteristics of feral cats on Marion Island. Journal of Applied Ecology 24 63 73

Veitch C. R. (1985). Methods of eradicating feral cats from offshore islands in New Zealand. In ‘Conservation of Island Birds. Case Studies for the Management of Threatened Island Species’. (Ed. P. J. Moors.) pp. 125–141. (International Council for Bird Preservation Technical Publication: Cambridge.)

Veitch C. R. 2001 The eradication of feral cats (Felis catus) from Little Barrier Island, New Zealand. New Zealand Journal of Zoology 28 1 12

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