Spot on: using camera traps to individually monitor one of the world’s largest lizards
Harry A. Moore
A E , Jacob L. Champney B , Judy A. Dunlop C , Leonie E. Valentine D and Dale G. Nimmo A
+ Author Affiliations
- Author Affiliations
A School of Environmental Science, Institute for Land, Water and Society, Charles Sturt University, 386 Elizabeth Mitchell Dr, Thurgoona, NSW 2640, Australia.
B University of the Sunshine Coast, 90 Sippy Downs Drive, Sippy Downs, Qld 4556, Australia.
C Department of Biodiversity, Conservation and Attractions, Locked Bag 104, Bentley Delivery Centre, Perth, WA, Australia.
D School of Biological Sciences, University of Western Australia, 35 Stirling Hwy, Crawley WA 6009, Australia.
E Corresponding author. Email: harryamos@live.com.au
Wildlife Research 47(4) 326-337 https://doi.org/10.1071/WR19159
Submitted: 9 September 2019 Accepted: 11 December 2019 Published: 11 May 2020
Abstract
Context: Estimating animal abundance often relies on being able to identify individuals; however, this can be challenging, especially when applied to large animals that are difficult to trap and handle. Camera traps have provided a non-invasive alternative by using natural markings to individually identify animals within image data. Although camera traps have been used to individually identify mammals, they are yet to be widely applied to other taxa, such as reptiles.
Aims: We assessed the capacity of camera traps to provide images that allow for individual identification of the world’s fourth-largest lizard species, the perentie (Varanus giganteus), and demonstrate other basic morphological and behavioural data that can be gleaned from camera-trap images.
Methods: Vertically orientated cameras were deployed at 115 sites across a 10 000 km2 area in north-western Australia for an average of 216 days. We used spot patterning located on the dorsal surface of perenties to identify individuals from camera-trap imagery, with the assistance of freely available spot ID software. We also measured snout-to-vent length (SVL) by using image-analysis software, and collected image time-stamp data to analyse temporal activity patterns.
Results: Ninety-two individuals were identified, and individuals were recorded moving distances of up to 1975 m. Confidence in identification accuracy was generally high (91%), and estimated SVL measurements varied by an average of 6.7% (min = 1.8%, max = 21.3%) of individual SVL averages. Larger perenties (SVL of >45 cm) were detected mostly between dawn and noon, and in the late afternoon and early evening, whereas small perenties (SVL of <30 cm) were rarely recorded in the evening.
Conclusions: Camera traps can be used to individually identify large reptiles with unique markings, and can also provide data on movement, morphology and temporal activity. Accounting for uneven substrates under cameras could improve the accuracy of morphological estimates. Given that camera traps struggle to detect small, nocturnal reptiles, further research is required to examine whether cameras miss smaller individuals in the late afternoon and evening.
Implications: Camera traps are increasingly being used to monitor reptile species. The ability to individually identify animals provides another tool for herpetological research worldwide.
Additional keywords: ecology, mark–recapture, wildlife management.
References
Abramoff, M. D., Magalhaes, P. J., and Ram, S. J. (2004). Image processing with ImageJ. Biophotonics International 11, 36–42.Alexander, P. D., and Gese, E. M. (2018). Identifying individual cougars (Puma concolor) in remote camera images: implications for population estimates. Wildlife Research 45, 274–281.
| Identifying individual cougars (Puma concolor) in remote camera images: implications for population estimates.Crossref | GoogleScholarGoogle Scholar |
Allen, M. L., Peterson, B., and Krofel, M. (2018). No respect for apex carnivores: distribution and activity patterns of honey badgers in the Serengeti. Mammalian Biology 89, 90–94.
| No respect for apex carnivores: distribution and activity patterns of honey badgers in the Serengeti.Crossref | GoogleScholarGoogle Scholar |
Alonso, R. S., McClintock, B. T., Lyren, L. M., Boydston, E. E., and Crooks, K. R. (2015). Mark–recapture and mark–resight methods for estimating abundance with remote cameras: a carnivore case study. PLoS One 10, e0123032.
| Mark–recapture and mark–resight methods for estimating abundance with remote cameras: a carnivore case study.Crossref | GoogleScholarGoogle Scholar | 25822245PubMed |
Azevedo, F., Lemos, F., Freitas‐Junior, M., Rocha, D., and Azevedo, F. (2018). Puma activity patterns and temporal overlap with prey in a human‐modified landscape at southeastern Brazil. Journal of Zoology 305, 246–255.
| Puma activity patterns and temporal overlap with prey in a human‐modified landscape at southeastern Brazil.Crossref | GoogleScholarGoogle Scholar |
Bastille‐Rousseau, G., Wall, J., Douglas‐Hamilton, I., and Wittemyer, G. (2018). Optimizing the positioning of wildlife crossing structures using GPS telemetry. Journal of Applied Ecology 55, 2055–2063.
| Optimizing the positioning of wildlife crossing structures using GPS telemetry.Crossref | GoogleScholarGoogle Scholar |
Bennett, D., and Clements, T. (2014). The use of passive infrared camera trapping systems in the study of frugivorous monitor lizards. Biawak 8, 19–30.
Bennett, A. F., Radford, J. Q., and Haslem, A. (2006). Properties of land mosaics: implications for nature conservation in agricultural environments. Biological Conservation 133, 250–264.
| Properties of land mosaics: implications for nature conservation in agricultural environments.Crossref | GoogleScholarGoogle Scholar |
Bureau of Meteorology (BOM) (2019). ‘Climate data online.’ Available at http://www.bom.gov.au/climate/data/ [verified 20 August 2019].
Brieger, F., Hagen, R., Kröschel, M., Hartig, F., Petersen, I., Ortmann, S., and Suchant, R. (2017). Do roe deer react to wildlife warning reflectors? A test combining a controlled experiment with field observations. European Journal of Wildlife Research 63, 72.
| Do roe deer react to wildlife warning reflectors? A test combining a controlled experiment with field observations.Crossref | GoogleScholarGoogle Scholar |
Brooks, K., Rowat, D., Pierce, S. J., Jouannet, D., and Vely, M. (2010). Seeing spots: photo-identification as a regional tool for whale shark identification. Western Indian Ocean Journal of Marine Science 9, 185–194.
Burton, A. C., Neilson, E., Moreira, D., Ladle, A., Steenweg, R., Fisher, J. T., Bayne, E., and Boutin, S. (2015). Wildlife camera trapping: a review and recommendations for linking surveys to ecological processes. Journal of Applied Ecology 52, 675–685.
| Wildlife camera trapping: a review and recommendations for linking surveys to ecological processes.Crossref | GoogleScholarGoogle Scholar |
Cerutti-Pereyra, F., Bassos-Hull, K., Arvizu-Torres, X., Wilkinson, K., García-Carrillo, I., Perez-Jimenez, J., and Hueter, R. (2018). Observations of spotted eagle rays (Aetobatus narinari) in the Mexican Caribbean using photo-ID. Environmental Biology of Fishes 101, 237–244.
| Observations of spotted eagle rays (Aetobatus narinari) in the Mexican Caribbean using photo-ID.Crossref | GoogleScholarGoogle Scholar |
Chen, I.-P., Symonds, M. R., Melville, J., and Stuart-Fox, D. (2013). Factors shaping the evolution of colour patterns in Australian agamid lizards (Agamidae): a comparative study. Biological Journal of the Linnean Society. Linnean Society of London 109, 101–112.
| Factors shaping the evolution of colour patterns in Australian agamid lizards (Agamidae): a comparative study.Crossref | GoogleScholarGoogle Scholar |
De Bondi, N., White, J. G., Stevens, M., and Cooke, R. (2010). A comparison of the effectiveness of camera trapping and live trapping for sampling terrestrial small-mammal communities. Wildlife Research 37, 456–465.
| A comparison of the effectiveness of camera trapping and live trapping for sampling terrestrial small-mammal communities.Crossref | GoogleScholarGoogle Scholar |
den Hartog, J., and Reijns, R. (2008). I3S Manta manual: interactive individual identification system. Version 2.1. Available at http://www.reijns.com/i3s/download/I3SM%20v2.1.pdf [verified 29 June 2019].
Doody, J., Green, B., Sims, R., Rhind, D., West, P., and Steer, D. (2006). Indirect impacts of invasive cane toads (Bufo marinus) on nest predation in pig-nosed turtles (Carettochelys insculpta). Wildlife Research 33, 349–354.
| Indirect impacts of invasive cane toads (Bufo marinus) on nest predation in pig-nosed turtles (Carettochelys insculpta).Crossref | GoogleScholarGoogle Scholar |
Doughty, P., Rolfe, J. K., Burbidge, A. H., Pearson, D. J., and Kendrick, P. G. (2011). Herpetological assemblages of the Pilbara biogeographic region, Western Australia: ecological associations, biogeographic patterns and conservation. Records of the Western Australian Museum 78, 315–341.
| Herpetological assemblages of the Pilbara biogeographic region, Western Australia: ecological associations, biogeographic patterns and conservation.Crossref | GoogleScholarGoogle Scholar |
ESRI (2017). ‘ArcGIS for Desktop. Ver. 10.5.1.’ (Environmental System Research Institute, Inc.: Redlands, CA, USA.)
Fahrig, L. (2003). Effects of habitat fragmentation on biodiversity. Annual Review of Ecology, Evolution, and Systematics 34, 487–515.
| Effects of habitat fragmentation on biodiversity.Crossref | GoogleScholarGoogle Scholar |
Fancourt, B. A., Hawkins, C. E., Cameron, E. Z., Jones, M. E., and Nicol, S. C. (2015). Devil declines and catastrophic cascades: is mesopredator release of feral cats inhibiting recovery of the eastern quoll? PLoS One 10, e0119303.
| Devil declines and catastrophic cascades: is mesopredator release of feral cats inhibiting recovery of the eastern quoll?Crossref | GoogleScholarGoogle Scholar | 26106887PubMed |
Foster, R. J., and Harmsen, B. J. (2012). A critique of density estimation from camera‐trap data. The Journal of Wildlife Management 76, 224–236.
| A critique of density estimation from camera‐trap data.Crossref | GoogleScholarGoogle Scholar |
French, R. K., Muller, C. G., Chilvers, B. L., and Battley, P. F. (2019). Behavioural consequences of human disturbance on subantarctic yellow-eyed penguins, Megadyptes antipodes. Bird Conservation International 29, 277–290.
| Behavioural consequences of human disturbance on subantarctic yellow-eyed penguins, Megadyptes antipodes.Crossref | GoogleScholarGoogle Scholar |
Fry, B. G., Vidal, N., Norman, J. A., Vonk, F. J., Scheib, H., Ramjan, S. R., Kuruppu, S., Fung, K., Hedges, S. B., and Richardson, M. K. (2006). Early evolution of the venom system in lizards and snakes. Nature 439, 584–588.
| Early evolution of the venom system in lizards and snakes.Crossref | GoogleScholarGoogle Scholar | 16292255PubMed |
Garrick, D. (2008). Body surface temperature and length in relation to the thermal biology of lizards. Bioscience Horizons 1, 136–142.
| Body surface temperature and length in relation to the thermal biology of lizards.Crossref | GoogleScholarGoogle Scholar |
GéCzy, C. (2009). Cannibalism in captive Varanus timorensis. Biawak 3, 61–63.
Gibbons, J. W., Scott, D. E., Ryan, T. J., Buhlmann, K. A., Tuberville, T. D., Metts, B. S., Greene, J. L., Mills, T., Leiden, Y., and Poppy, S. (2000). The global decline of reptiles, déjà vu amphibians: reptile species are declining on a global scale. Six significant threats to reptile populations are habitat loss and degradation, introduced invasive species, environmental pollution, disease, unsustainable use, and global climate change. Bioscience 50, 653–666.
Green, B., and King, D. (1978). Home range and activity patterns of the sand goanna, Varanus gouldii (Reptilia: Varanidae). Wildlife Research 5, 417–424.
| Home range and activity patterns of the sand goanna, Varanus gouldii (Reptilia: Varanidae).Crossref | GoogleScholarGoogle Scholar |
Guarino, F. (2002). Spatial ecology of a large carnivorous lizard, Varanus varius (Squamata: Varanidae). Journal of Zoology 258, 449–457.
| Spatial ecology of a large carnivorous lizard, Varanus varius (Squamata: Varanidae).Crossref | GoogleScholarGoogle Scholar |
Hernandez-Santin, L., Goldizen, A. W., and Fisher, D. O. (2016). Introduced predators and habitat structure influence range contraction of an endangered native predator, the northern quoll. Biological Conservation 203, 160–167.
| Introduced predators and habitat structure influence range contraction of an endangered native predator, the northern quoll.Crossref | GoogleScholarGoogle Scholar |
Hertel, A. G., Leclerc, M., Warren, D., Pelletier, F., Zedrosser, A., and Mueller, T. (2019). Don’t poke the bear: using tracking data to quantify behavioural syndromes in elusive wildlife. Animal Behaviour 147, 91–104.
| Don’t poke the bear: using tracking data to quantify behavioural syndromes in elusive wildlife.Crossref | GoogleScholarGoogle Scholar |
Higashide, D., Miura, S., and Miguchi, H. (2012). Are chest marks unique to Asiatic black bear individuals? Journal of Zoology 288, 199–206.
| Are chest marks unique to Asiatic black bear individuals?Crossref | GoogleScholarGoogle Scholar |
Hohnen, R., Ashby, J., Tuft, K., and McGregor, H. (2013). Individual identification of northern quolls (Dasyurus hallucatus) using remote cameras. Australian Mammalogy 35, 131–135.
| Individual identification of northern quolls (Dasyurus hallucatus) using remote cameras.Crossref | GoogleScholarGoogle Scholar |
Jessop, T. S., Madsen, T., Sumner, J., Rudiharto, H., Phillips, J. A., and Ciofi, C. (2006). Maximum body size among insular Komodo dragon populations covaries with large prey density. Oikos 112, 422–429.
| Maximum body size among insular Komodo dragon populations covaries with large prey density.Crossref | GoogleScholarGoogle Scholar |
Jhala, Y., Qureshi, Q., and Gopal, R. (2011). Can the abundance of tigers be assessed from their signs? Journal of Applied Ecology 48, 14–24.
| Can the abundance of tigers be assessed from their signs?Crossref | GoogleScholarGoogle Scholar |
Johnson, C. R. (1976). Some behavioural observations on wild and captive sand monitors, Varanus gouldii (Sauria: Varanidae). Zoological Journal of the Linnean Society 59, 377–380.
| Some behavioural observations on wild and captive sand monitors, Varanus gouldii (Sauria: Varanidae).Crossref | GoogleScholarGoogle Scholar |
Kellner, C. J., Lawson, G. R., Tomke, S. A., and Noble, J. H. (2017). Computer-aided individual identification of Sceloporus consobrinus based on patterns of head scalation. Herpetological Review 48, 766–769.
Kendall, W. L. (1999). Robustness of closed capture–recapture methods to violations of the closure assumption. Ecology 80, 2517–2525.
King, D., and Green, B. (1999) ‘Goannas: the biology of varanid lizards.’ (UNSW Press: Sydney, NSW, Australia.)
King, M., and Horner, P. (1987). A new species of monitor (Reptilia: Platynota) from northern Australia and a note on the status of Varanus acanthurus insulanicus Mertens. The Beagle: Records of the Museums and Art Galleries of the Northern Territory 4, 73–77.
King, D., Green, B., and Butler, H. (1989). The activity pattern, temperature regulation and diet of Varanus-giganteus on Barrow-Island, Western-Australia. Wildlife Research 16, 41–47.
| The activity pattern, temperature regulation and diet of Varanus-giganteus on Barrow-Island, Western-Australia.Crossref | GoogleScholarGoogle Scholar |
Lashley, M. A., Cove, M. V., Chitwood, M. C., Penido, G., Gardner, B., DePerno, C. S., and Moorman, C. E. (2018). Estimating wildlife activity curves: comparison of methods and sample size. Scientific Reports 8, 4173.
| Estimating wildlife activity curves: comparison of methods and sample size.Crossref | GoogleScholarGoogle Scholar | 29520029PubMed |
Lei, J., and Booth, D. T. (2017). Intraspecific variation in space use of a coastal population of lace monitors (Varanus varius). Australian Journal of Zoology 65, 398–407.
| Intraspecific variation in space use of a coastal population of lace monitors (Varanus varius).Crossref | GoogleScholarGoogle Scholar |
Li, D., Liu, Y., Sun, X., Lloyd, H., Zhu, S., Zhang, S., Wan, D., and Zhang, Z. (2017). Habitat-dependent changes in vigilance behaviour of red-crowned crane influenced by wildlife tourism. Scientific Reports 7, 16614.
| Habitat-dependent changes in vigilance behaviour of red-crowned crane influenced by wildlife tourism.Crossref | GoogleScholarGoogle Scholar | 29192203PubMed |
McKenzie, N., Van Leeuwen, S., and Pinder, A. (2009). Introduction to the Pilbara biodiversity survey, 2002–2007. Records of the Western Australian Museum 78, 3–89.
| Introduction to the Pilbara biodiversity survey, 2002–2007.Crossref | GoogleScholarGoogle Scholar |
Meek, P. D., Fleming, P., and Ballard, G. (2012). ‘An Introduction to Camera Trapping for Wildlife Surveys in Australia.’ (Invasive Animals Cooperative Research Centre: Canberra.)
Menkhorst, P., and Knight, F. (2001) ‘Field guide to the mammals of Australia.’ (Oxford University Press: New York, NY, USA.)
Meredith, M. and Ridout, M. (2014). ‘‘R. Proj’: Overview of the Overlap Package.’ Available at https://cran.r-project.org/web/packages/overlap/vignettes/overlap.pdf [verified 29 June 2019].
Molyneux, J., Pavey, C., James, A., and Carthew, S. (2017). The efficacy of monitoring techniques for detecting small mammals and reptiles in arid environments. Wildlife Research 44, 534–545.
| The efficacy of monitoring techniques for detecting small mammals and reptiles in arid environments.Crossref | GoogleScholarGoogle Scholar |
Moro, D., and MacAulay, I. (2014). Computer-aided pattern recognition of large reptiles as a noninvasive application to identify individuals. Journal of Applied Animal Welfare Science 17, 125–135.
| Computer-aided pattern recognition of large reptiles as a noninvasive application to identify individuals.Crossref | GoogleScholarGoogle Scholar | 24665952PubMed |
Morton, A. (1982). The effects of marking and capture on recapture frequencies of butterflies. Oecologia 53, 105–110.
| The effects of marking and capture on recapture frequencies of butterflies.Crossref | GoogleScholarGoogle Scholar | 28310610PubMed |
Polis, G. A., and Myers, C. A. (1985). A survey of intraspecific predation among reptiles and amphibians. Journal of Herpetology 19, 99–107.
| A survey of intraspecific predation among reptiles and amphibians.Crossref | GoogleScholarGoogle Scholar |
Pollock, K. H. (1980). ‘Capture–recapture Models: a Review of Current Methods, Assumptions and Experimental Design.’ (CiteSeer: Raleigh, NC, USA)
Pradel, R. (1996). Utilization of capture–mark–recapture for the study of recruitment and population growth rate. Biometrics 52, 703–709.
| Utilization of capture–mark–recapture for the study of recruitment and population growth rate.Crossref | GoogleScholarGoogle Scholar |
R Core Team (2013). ‘R: a Language and Environment for Statistical Computing.’ (R Foundation for Statistical Computing: Vienna.)
Read, J. L., and Scoleri, V. (2015). Ecological implications of reptile mesopredator release in arid South Australia. Journal of Herpetology 49, 64–69.
| Ecological implications of reptile mesopredator release in arid South Australia.Crossref | GoogleScholarGoogle Scholar |
Richardson, E., Nimmo, D. G., Avitabile, S., Tworkowski, L., Watson, S. J., Welbourne, D., and Leonard, S. W. (2017). Camera traps and pitfalls: an evaluation of two methods for surveying reptiles in a semiarid ecosystem. Wildlife Research 44, 637–647.
| Camera traps and pitfalls: an evaluation of two methods for surveying reptiles in a semiarid ecosystem.Crossref | GoogleScholarGoogle Scholar |
Ridout, M. S., and Linkie, M. (2009). Estimating overlap of daily activity patterns from camera trap data. Journal of Agricultural Biological & Environmental Statistics 14, 322–337.
| Estimating overlap of daily activity patterns from camera trap data.Crossref | GoogleScholarGoogle Scholar |
Rodda, G. H., Bock, B. C., Burghardt, G. M., and Rand, A. S. (1988). Techniques for identifying individual lizards at a distance reveal influences of handling. Copeia 1988, 905–913.
| Techniques for identifying individual lizards at a distance reveal influences of handling.Crossref | GoogleScholarGoogle Scholar |
Rostro-García, S., Kamler, J. F., Crouthers, R., Sopheak, K., Prum, S., In, V., Pin, C., Caragiulo, A., and Macdonald, D. W. (2018). An adaptable but threatened big cat: density, diet and prey selection of the Indochinese leopard (Panthera pardus delacouri) in eastern Cambodia. Royal Society Open Science 5, 171–187.
| An adaptable but threatened big cat: density, diet and prey selection of the Indochinese leopard (Panthera pardus delacouri) in eastern Cambodia.Crossref | GoogleScholarGoogle Scholar |
Rovero, F., Zimmermann, F., Berzi, D., and Meek, P. (2013). Which camera trap type and how many do I need? A review of camera features and study designs for a range of wildlife research applications. Hystrix 24, 148–156.
Rowat, D., Speed, C. W., Meekan, M. G., Gore, M. A., and Bradshaw, C. J. (2009). Population abundance and apparent survival of the vulnerable whale shark, Rhincodon typus, in the Seychelles aggregation. Oryx 43, 591–598.
| Population abundance and apparent survival of the vulnerable whale shark, Rhincodon typus, in the Seychelles aggregation.Crossref | GoogleScholarGoogle Scholar |
Ruxmoore, R., and Groombridge, B. (1990). ‘Asian Monitor Lizards: a Review of Distribution, Status, Exploitation, and Trade in Four Selected Species.’ (Secretariat of the Convention on International Trade in Endangered Species of Wild Fauna and Flora: Lausanne, Switzerland.)
Sanecki, G. M., and Green, K. (2005). A technique for using hair tubes beneath the snowpack to detect winter-active small mammals in the subnivean space. European Journal of Wildlife Research 51, 41–47.
| A technique for using hair tubes beneath the snowpack to detect winter-active small mammals in the subnivean space.Crossref | GoogleScholarGoogle Scholar |
Sannolo, M., Gatti, F., Mangiacotti, M., Scali, S., and Sacchi, R. (2016). Photo-identification in amphibian studies: a test of I3S pattern. Acta Herpetologica 11, 63–68.
Schwarz, C. J., and Arnason, A. N. (1996). A general methodology for the analysis of capture–recapture experiments in open populations. Biometrics 52, 860–873.
| A general methodology for the analysis of capture–recapture experiments in open populations.Crossref | GoogleScholarGoogle Scholar |
Sears, M. W., Angilletta, M. J., Schuler, M. S., Borchert, J., Dilliplane, K. F., Stegman, M., Rusch, T. W., and Mitchell, W. A. (2016). Configuration of the thermal landscape determines thermoregulatory performance of ectotherms. Proceedings of the National Academy of Sciences of the United States of America 113, 10595–10600.
| Configuration of the thermal landscape determines thermoregulatory performance of ectotherms.Crossref | GoogleScholarGoogle Scholar | 27601639PubMed |
Shine, R. (2010). The ecological impact of invasive cane toads (Bufo marinus) in Australia. The Quarterly Review of Biology 85, 253–291.
| The ecological impact of invasive cane toads (Bufo marinus) in Australia.Crossref | GoogleScholarGoogle Scholar | 20919631PubMed |
Shine, R., and Harlow, P. S. (1998). Ecological traits of commercially harvested water monitors, Varanus salvator, in northern Sumatra. Wildlife Research 25, 437–447.
| Ecological traits of commercially harvested water monitors, Varanus salvator, in northern Sumatra.Crossref | GoogleScholarGoogle Scholar |
Silver, S. C., Ostro, L. E., Marsh, L. K., Maffei, L., Noss, A. J., Kelly, M. J., Wallace, R. B., Gomez, H., and Ayala, G. (2004). The use of camera traps for estimating jaguar Panthera onca abundance and density using capture/recapture analysis. Oryx 38, 148–154.
| The use of camera traps for estimating jaguar Panthera onca abundance and density using capture/recapture analysis.Crossref | GoogleScholarGoogle Scholar |
Smith, J., Brook, B., Griffiths, A., and Thompson, G. G. (2007). Can morphometrics predict sex in varanids? Journal of Herpetology 41, 133–140.
| Can morphometrics predict sex in varanids?Crossref | GoogleScholarGoogle Scholar |
Speed, C. W., Meekan, M. G., and Bradshaw, C. J. (2007). Spot the match: wildlife photo-identification using information theory. Frontiers in Zoology 4, 2.
| 17227581PubMed |
Stevenson, R. (1985). Body size and limits to the daily range of body temperature in terrestrial ectotherms. American Naturalist 125, 102–117.
| Body size and limits to the daily range of body temperature in terrestrial ectotherms.Crossref | GoogleScholarGoogle Scholar |
Sutherland, D. R., Glen, A. S., and de Tores, P. J. (2011). Could controlling mammalian carnivores lead to mesopredator release of carnivorous reptiles? Proceedings. Biological Sciences 278, 641–648.
| Could controlling mammalian carnivores lead to mesopredator release of carnivorous reptiles?Crossref | GoogleScholarGoogle Scholar | 21123272PubMed |
Thompson, G. G., and Withers, P. C. (1997). Comparative morphology of western Australian varanid lizards (Squamata: Varanidae). Journal of Morphology 233, 127–152.
| Comparative morphology of western Australian varanid lizards (Squamata: Varanidae).Crossref | GoogleScholarGoogle Scholar | 29852689PubMed |
Treilibs, C. E., Pavey, C. R., Hutchinson, M. N., and Bull, C. M. (2016). Photographic identification of individuals of a free‐ranging, small terrestrial vertebrate. Ecology and Evolution 6, 800–809.
| Photographic identification of individuals of a free‐ranging, small terrestrial vertebrate.Crossref | GoogleScholarGoogle Scholar | 26865967PubMed |
Tyne, J. A., Johnston, D. W., Christiansen, F., and Bejder, L. (2017). Temporally and spatially partitioned behaviours of spinner dolphins: implications for resilience to human disturbance. Royal Society Open Science 4, 160626.
| Temporally and spatially partitioned behaviours of spinner dolphins: implications for resilience to human disturbance.Crossref | GoogleScholarGoogle Scholar | 28280561PubMed |
Volkov, I., Banavar, J. R., Hubbell, S. P., and Maritan, A. (2003). Neutral theory and relative species abundance in ecology. Nature 424, 1035–1037.
| Neutral theory and relative species abundance in ecology.Crossref | GoogleScholarGoogle Scholar | 12944964PubMed |
Weinstein, B. G. (2018). A computer vision for animal ecology. Journal of Animal Ecology 87, 533–545.
| A computer vision for animal ecology.Crossref | GoogleScholarGoogle Scholar | 29111567PubMed |
Welbourne, D. (2013). A method for surveying diurnal terrestrial reptiles with passive infrared automatically triggered cameras. PLoS One 6, e18965.
Welbourne, D. J., MacGregor, C., Paull, D., and Lindenmayer, D. B. (2015). The effectiveness and cost of camera traps for surveying small reptiles and critical weight range mammals: a comparison with labour-intensive complementary methods. Wildlife Research 42, 414–425.
| The effectiveness and cost of camera traps for surveying small reptiles and critical weight range mammals: a comparison with labour-intensive complementary methods.Crossref | GoogleScholarGoogle Scholar |
Welbourne, D. J., Claridge, A. W., Paull, D. J., and Lambert, A. (2016). How do passive infrared triggered camera traps operate and why does it matter? Breaking down common misconceptions. Remote Sensing in Ecology and Conservation 2, 77–83.
| How do passive infrared triggered camera traps operate and why does it matter? Breaking down common misconceptions.Crossref | GoogleScholarGoogle Scholar |
Welbourne, D. J., Paull, D. J., Claridge, A. W., and Ford, F. (2017). A frontier in the use of camera traps: surveying terrestrial squamate assemblages. Remote Sensing in Ecology and Conservation 3, 133–145.
| A frontier in the use of camera traps: surveying terrestrial squamate assemblages.Crossref | GoogleScholarGoogle Scholar |
Welbourne, D., Claridge, A., Paull, D., and Ford, F. (2019). Improving terrestrial squamate surveys with camera-trap programming and hardware modifications. Animals (Basel) 9, 388.
| Improving terrestrial squamate surveys with camera-trap programming and hardware modifications.Crossref | GoogleScholarGoogle Scholar |
Wickham, H. and Wickham, M. H. (2019). ‘CRAN.R: Package ‘ggplot2’.’ Available at https://cran.r-project.org/web/packages/ggplot2/ggplot2.pdf [verified 11 August 2019].
Wilson, S. K., and Swan, G. (2017). ‘A Complete Guide to Reptiles of Australia.’ (Reed New Holland: Sydney.)
Withers, P. (2000). Overview of granite outcrops in Western Australia. Journal of the Royal Society of Western Australia 83, 103.
