Estimating and indexing feral cat population abundances using camera traps
Andrew Bengsen A B , John Butler A and Pip Masters AA Kangaroo Island Natural Resources Management Board, 35 Dauncey Street, Kingscote, SA 5223, Australia.
B Corresponding author. Present address: NSW Department of Primary Industries, Locked Bag 6006, Orange, NSW 2800, Australia. Email: andrew.bengsen@uqconnect.edu.au
Wildlife Research 38(8) 732-739 https://doi.org/10.1071/WR11134
Submitted: 26 July 2011 Accepted: 20 October 2011 Published: 9 December 2011
Abstract
Context: The ability to monitor changes in population abundance is critical to the success of pest animal management and research programs. Feral cats (Felis catus) are an important pest animal, but current monitoring techniques have limited sensitivity or are limited in use to particular circumstances or habitats. Recent advances in camera-trapping methods provide the potential to identify individual feral cats, and to use this information to estimate population abundances using capture–mark–recapture (CMR) methods.
Aims: Here, we use a manipulative study to test whether camera-trapping and CMR methods can be used to estimate feral cat abundances.
Methods: We established a grid of infrared cameras and lure stations over three pastoral properties on Kangaroo Island, Australia, for 15 days. We then reduced the population abundance with an intensive trapping program and repeated the camera survey. We estimated population abundances using robust design CMR models, and converted abundance estimates to densities using home-range data from GPS tracking. We also calculated relative abundance indices from the same data.
Key results: The CMR methods produced credible estimates of the change in population abundance, with useful confidence intervals, showing a statistically identifiable population decline from at least 0.7 cats km–2 before trapping down to 0.4 cats km–2 after trapping. The indexing method also showed a statistically identifiable decrease in abundance.
Conclusions: Camera-trapping and CMR methods can provide a useful method for monitoring changes in the absolute abundance of feral cat populations. Camera-trap data may also be used to produce indices of relative abundance when the assumptions of CMR models cannot be met.
Implications: These methods are widely applicable. The ability to reliably estimate feral cat abundances allows for more effective management than is generally available.
Additional keywords: abundance index, camera trap, Felis catus, feral cat, mark–recapture.
References
Baillargeon, S., and Rivest, L. P. (2007). Rcapture: loglinear models for capture–recapture in R. Journal of Statistical Software 19, 1–31.Bates, D., and Maechler, M. (2009). lme4: Linear mixed-effects models using S4 classes. R package version 0.999375-18. Available at http://CRAN.R-project.org/package=lme4 [verified November 2011]
Bengsen, A. J., Leung, L. K. P., Lapidge, S. J., and Gordon, I. J. (2011). Using a general index approach to analyze camera-trap abundance indices. The Journal of Wildlife Management 75, 1222–1227.
| Using a general index approach to analyze camera-trap abundance indices.Crossref | GoogleScholarGoogle Scholar |
Burnham, K. P., Anderson, D. R., White, G. C., Brownie, C., and Pollock, K. H. (1987) Design and analysis methods for fish survival experiments based on release–recapture. Monograph 5. American Fisheries Society, Bethesda, MD.
Caughley, G. (1977). ‘Analysis of Vertebrate Populations.’ (Wiley: New York.)
Conn, P., Bailey, L., and Sauer, J. (2004) Indexes as surrogates to abundance for low-abundance species. In ‘Sampling Rare or Elusive Species: Concepts, Designs, and Techniques for Estimating Population Parameters’. (Ed. W. L. Thompson.) pp. 59–74. (Island Press: Washington, DC.)
Edwards, G. P., De Preu, N. D., Shakeshaft, B. J., and Crealy, I. V. (2000). An evaluation of two methods of assessing feral cat and dingo abundance in central Australia. Wildlife Research 27, 143–149.
| An evaluation of two methods of assessing feral cat and dingo abundance in central Australia.Crossref | GoogleScholarGoogle Scholar |
Engeman, R. M. (2005). Indexing principles and a widely applicable paradigm for indexing animal populations. Wildlife Research 32, 203–210.
| Indexing principles and a widely applicable paradigm for indexing animal populations.Crossref | GoogleScholarGoogle Scholar |
Forsyth, D. M., Robley, A. J., and Reddiex, B. (2005). ‘Review of Methods Used to Estimate the Abundance of Feral Cats.’ (Arthur Rylah Institute for Environmental Research: Melbourne.)
Genovesi, P., Besa, M., and Toso, S. (1995). Ecology of a feral cat Felis catus population in an agricultural area of northern Italy. Wildlife Biology 1, 233–237.
Karanth, K. U., and Nichols, J. D. (1998). Estimation of tiger densities in India using photographic captures and recaptures. Ecology 79, 2852–2862.
| Estimation of tiger densities in India using photographic captures and recaptures.Crossref | GoogleScholarGoogle Scholar |
Kays, R. W., and Slauson, K. M. (2008). Remote cameras. In ‘Noninvasive Survey Methods for Carnivores’. (Eds R. A. Long, P. MacKay, J. Ray and W. Zielinski.) pp. 110–140. (Island Press: Washington, DC.)
Kays, R., Kranstauber, B., Jansen, P., Carbone, C., Rowcliffe, M., Fountain, T., and Tilak, S. (2009). Camera traps as sensor networks for monitoring animal communities. In ‘The 34th IEEE Conference on Local Computer Networks’. pp. 811–818. (IEEE Computer Society: Zurich.)
Keitt, B. S., and Tershy, B. R. (2003). Cat eradication significantly reduces shearwater mortality. Animal Conservation 6, 307–308.
| Cat eradication significantly reduces shearwater mortality.Crossref | GoogleScholarGoogle Scholar |
MacKenzie, D., Nichols, J., Royle, J., Pollock, K., Bailey, L., and Hines, J. (2006). ‘Occupancy Estimation and Modeling: Inferring Patterns and Dynamics of Species Occurrence.’ (Academic Press: Burlington, MA.)
Mahon, P. S., Banks, P. B., and Dickman, C. R. (1998). Population indices for wild carnivores: a critical study in sand-dune habitat, south-western Queensland. Wildlife Research 25, 11–22.
| Population indices for wild carnivores: a critical study in sand-dune habitat, south-western Queensland.Crossref | GoogleScholarGoogle Scholar |
McLeod, R. (2004). ‘Counting the Cost: Impact of Invasive Animals in Australia 2004.’ (Cooperative Research Centre for Pest Animal Control: Canberra.)
Moseby, K., Stott, J., and Crisp, H. (2009). Movement patterns of feral predators in an arid environment – implications for control through poison baiting. Wildlife Research 36, 422–435.
| Movement patterns of feral predators in an arid environment – implications for control through poison baiting.Crossref | GoogleScholarGoogle Scholar |
Newbold, H., and King, C. (2009). Can a predator see ‘invisible’ light? Infrared vision in ferrets (Mustelo furo). Wildlife Research 36, 309–318.
| Can a predator see ‘invisible’ light? Infrared vision in ferrets (Mustelo furo).Crossref | GoogleScholarGoogle Scholar |
Nogales, M., Martín, A., Tershy, B., Donlan, C., Veitch, D., Puerta, N., Wood, B., and Alonso, J. (2004). A review of feral cat eradication on islands. Conservation Biology 18, 310–319.
| A review of feral cat eradication on islands.Crossref | GoogleScholarGoogle Scholar |
Otis, D., Burnham, K., White, G., and Anderson, D. (1978). Statistical inference from capture data on closed animal populations. Wildlife Monographs 62, 3–135.
Paton, D. (1994). Ecology of cats in South Australia and testing possible methods of control: annual progress report. University of Adelaide.
Pollock, K. (1982). A capture-recapture design robust to unequal probability of capture. The Journal of Wildlife Management 46, 752–757.
| A capture-recapture design robust to unequal probability of capture.Crossref | GoogleScholarGoogle Scholar |
R Development Core Team (2011). R: A Language and Environment for Statistical Computing. Available at: http://www.R-project.org (R Foundation for Statistical Computing: Vienna.)
Read, J., and Eldridge, S. (2010). An optimised rapid detection technique for simultaneously monitoring activity of rabbits, cats, foxes and dingoes in the rangelands. The Rangeland Journal 32, 389–394.
| An optimised rapid detection technique for simultaneously monitoring activity of rabbits, cats, foxes and dingoes in the rangelands.Crossref | GoogleScholarGoogle Scholar |
Risbey, D. A., Calver, M. C., Short, J., Bradley, J. S., and 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.
| The impact of cats and foxes on the small vertebrate fauna of Heirisson Prong, Western Australia. II. A field experiment.Crossref | GoogleScholarGoogle Scholar |
Rivest, L., and Baillargeon, S. (2007). Applications and extensions of Chao’s moment estimator for the size of a closed population. Biometrics 63, 999–1006.
| Applications and extensions of Chao’s moment estimator for the size of a closed population.Crossref | GoogleScholarGoogle Scholar |
Robley, A., Gormley, A., Woodford, L., Lindeman, M., Whitehead, B., Albert, R., Bowd, M., and Smith, A. (2010). ‘Evaluation of Camera Trap Sampling Designs Used to Determine Change in Occupancy Rate and Abundance of Feral Cats.’ (Arthur Rylah Institute for Environmental Research: Melbourne.)
Swann, D. E., Hass, C. C., Dalton, D. C., and Wolf, S. A. (2004). Infrared-triggered cameras for detecting wildlife: an evaluation and review. Wildlife Society Bulletin 32, 357–365.
| Infrared-triggered cameras for detecting wildlife: an evaluation and review.Crossref | GoogleScholarGoogle Scholar |
Turner, D. C., and Meister, O. (1988). Hunting behaviour of the domestic cat. In ‘The Domestic Cat: the Biology of its Behaviour’. (Eds D. C. Turner and P. Bateson.) pp. 111–121. (Cambridge University Press: Cambridge, UK.)
Van Aarde, R. (1979). Distribution and density of the feral house cat Felis catus on Marion Island. South African Journal of Antarctic Research 9, 14–19.
Wegge, P., Pokheral, C., and Jnawali, S. (2004). Effects of trapping effort and trap shyness on estimates of tiger abundance from camera trap studies. Animal Conservation 7, 251–256.
| Effects of trapping effort and trap shyness on estimates of tiger abundance from camera trap studies.Crossref | GoogleScholarGoogle Scholar |
Wilson, G. J., and Delahay, R. J. (2001). A review of methods to estimate the abundance of terrestrial carnivores using field signs and observation. Wildlife Research 28, 151–164.
| A review of methods to estimate the abundance of terrestrial carnivores using field signs and observation.Crossref | GoogleScholarGoogle Scholar |
