Register      Login
Wildlife Research Wildlife Research Society
Ecology, management and conservation in natural and modified habitats
RESEARCH ARTICLE (Open Access)

A comparison of methods for monitoring a sparse population of the red fox (Vulpes vulpes) subject to lethal control using GPS telemetry, camera traps and sand plots

Andrew Carter https://orcid.org/0000-0001-5496-6706 A B * , Joanne M. Potts C , Joanne Stephens A and David A. Roshier https://orcid.org/0000-0002-8151-8447 A D
+ Author Affiliations
- Author Affiliations

A Australian Wildlife Conservancy, PO Box 8070, Subiaco East, WA 6008, Australia.

B Gulbali Institute of Agriculture, Water and Environment, Charles Sturt University, PO Box 789, Albury, NSW 2640, Australia.

C The Analytical Edge Pty Ltd, PO Box 47, Blackmans Bay, Tas. 7052, Australia.

D School of Animal and Veterinary Science, University of Adelaide, Roseworthy, SA 5371, Australia.

* Correspondence to: acarter@csu.edu.au

Handling Editor: Catarina Campos Ferreira

Wildlife Research 50(5) 366-380 https://doi.org/10.1071/WR22017
Submitted: 5 February 2022  Accepted: 23 August 2022   Published: 14 October 2022

© 2023 The Author(s) (or their employer(s)). Published by CSIRO Publishing. This is an open access article distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND)

Abstract

Context: The introduced red fox has driven the decline or extinction of numerous wildlife species in Australia, yet little information exists on the population densities of foxes in most ecosystems. Fox monitoring programs will differ widely depending on the goals of management, which, in turn, will determine whether the appropriate metric is a density estimate, or some proxy thereof, and the time and resources required.

Aims: This study aims to assist wildlife managers to design fit-for-purpose monitoring programs for foxes by providing a better understanding of the utility and precision of various monitoring methods.

Methods: We surveyed foxes monthly over four consecutive years in a semi-arid region of Australia by using sand plots, camera traps and GPS telemetry. The resultant data were used to produce population estimates from one count-based method, two spatially explicit methods, and two activity indices.

Key results: The incorporation of GPS-collar data into the spatial capture–recapture approaches greatly reduced uncertainty in estimates of abundance. Activity indices from sand plots were generally higher and more variable than were indices derived from camera traps, whereas estimates from N-mixture models appeared to be biased high.

Conclusions: Our study indicated that the Allen–Engeman index derived from camera-trap data provided an accurate reflection of change in the underlying fox density, even as density declined towards zero following introduction of lethal control. This method provides an efficient means to detect large shifts in abundance, whether up or down, which may trigger a change to more laborious, but precise, population monitoring methods. If accuracy is paramount (e.g. for reintroduction programs) spatially explicit methods augmented with GPS data provide robust estimates, albeit at a greater cost in resources and expertise than does an index.

Implications: Our study demonstrated that the shorter the survey period is, the greater is the likelihood that foxes are present but not detected. As such, if limited resources are available, longer monitoring periods conducted less frequently will provide a more accurate reflection of the underlying fox population than do shorter monitoring periods conducted more often.

Keywords: canid pest ejector, fox baiting, mark–resight, N-mixture model, population index, predator control, sodium fluoroacetate, spatially explicit.


References

Akaike, H (1974). A new look at the statistical model identification. IEEE Transactions on Automatic Control 19, 716–723.
A new look at the statistical model identification.Crossref | GoogleScholarGoogle Scholar |

Allen, BL (2019). Para-aminopropiophenone (PAPP) in canid pest ejectors (CPEs) kills wild dogs and European red foxes quickly and humanely. Environmental Science and Pollution Research 26, 14494–14501.
Para-aminopropiophenone (PAPP) in canid pest ejectors (CPEs) kills wild dogs and European red foxes quickly and humanely.Crossref | GoogleScholarGoogle Scholar |

Anderson, DR (2001). The need to get the basics right in wildlife field studies. Wildlife Society Bulletin 19, 1294–1297.

Augustine, BC, Royle, JA, Kelly, MJ, Satter, CB, Alonso, RS, Boydston, EE, and Crooks, KR (2018). Spatial capture–recapture with partial identity: an application to camera traps. The Annals of Applied Statistics 12, 67–95.
Spatial capture–recapture with partial identity: an application to camera traps.Crossref | GoogleScholarGoogle Scholar |

Barker, RJ, Schofield, MR, Link, WA, and Sauer, JR (2018). On the reliability of N-mixture models for count data. Biometrics 74, 369–377.
On the reliability of N-mixture models for count data.Crossref | GoogleScholarGoogle Scholar |

Bengsen, A (2014). Effects of coordinated poison-baiting programs on survival and abundance in two red fox populations. Wildlife Research 41, 194–202.
Effects of coordinated poison-baiting programs on survival and abundance in two red fox populations.Crossref | GoogleScholarGoogle Scholar |

Benshemesh, J, Southwell, D, Barker, R, and McCarthy, M (2020). Citizen scientists reveal nationwide trends and drivers in the breeding activity of a threatened bird, the malleefowl (Leipoa ocellata). Biological Conservation 246, 108573.
Citizen scientists reveal nationwide trends and drivers in the breeding activity of a threatened bird, the malleefowl (Leipoa ocellata).Crossref | GoogleScholarGoogle Scholar |

Berry, O, Algar, D, Angus, J, Hamilton, N, Hilmer, S, and Sutherland, D (2012). Genetic tagging reveals a significant impact of poison baiting on an invasive species. The Journal of Wildlife Management 76, 729–739.
Genetic tagging reveals a significant impact of poison baiting on an invasive species.Crossref | GoogleScholarGoogle Scholar |

Berry, O, Tatler, J, Hamilton, N, Hilmer, S, Hitchen, Y, and Algar, D (2013). Slow recruitment in a red-fox population following poison baiting: a non-invasive mark–recapture analysis. Wildlife Research 40, 615–623.
Slow recruitment in a red-fox population following poison baiting: a non-invasive mark–recapture analysis.Crossref | GoogleScholarGoogle Scholar |

Borchers, DL, and Efford, MG (2008). Spatially explicit maximum likelihood methods for capture–recapture studies. Biometrics 64, 377–385.
Spatially explicit maximum likelihood methods for capture–recapture studies.Crossref | GoogleScholarGoogle Scholar |

Bradshaw, CJA, Hoskins, AJ, Haubrock, PJ, Cuthbert, RN, Diagne, C, Leroy, B, Andrews, L, Page, B, Cassey, P, Sheppard, AW, and Courchamp, F (2021). Detailed assessment of the reported economic costs of invasive species in Australia. NeoBiota 67, 511–550.
Detailed assessment of the reported economic costs of invasive species in Australia.Crossref | GoogleScholarGoogle Scholar |

Buckland, ST, Burnham, KP, and Augustin, NH (1997). Model selection: an integral part of inference. Biometrics 53, 603–618.
Model selection: an integral part of inference.Crossref | GoogleScholarGoogle Scholar |

Carter, A, Luck, GW, and McDonald, SP (2011). Fox-baiting in agricultural landscapes in south-eastern Australia: a case-study appraisal and suggestions for improvement. Ecological Management & Restoration 12, 214–223.
Fox-baiting in agricultural landscapes in south-eastern Australia: a case-study appraisal and suggestions for improvement.Crossref | GoogleScholarGoogle Scholar |

Carter, A, Potts, JM, and Roshier, DA (2019). Toward reliable population density estimates of partially marked populations using spatially explicit mark–resight methods. Ecology and Evolution 9, 2131–2141.
Toward reliable population density estimates of partially marked populations using spatially explicit mark–resight methods.Crossref | GoogleScholarGoogle Scholar |

Catling, PC, and Burt, RJ (1994). Studies of the ground-dwelling mammals of eucalypt forests in south-eastern New South Wales: the species, their abundance and distribution. Wildlife Research 21, 219–239.
Studies of the ground-dwelling mammals of eucalypt forests in south-eastern New South Wales: the species, their abundance and distribution.Crossref | GoogleScholarGoogle Scholar |

Caughley G (1977) ‘Analysis of vertebrate populations.’ (Wiley: New York, NY, USA)

Chandler, RB, and Royle, JA (2013). Spatially explicit models for inference about density in unmarked or partially marked populations. The Annals of Applied Statistics 7, 936–954.
Spatially explicit models for inference about density in unmarked or partially marked populations.Crossref | GoogleScholarGoogle Scholar |

Dexter, N, and Meek, P (1998). An analysis of bait-take and non-target impacts during a fox-control exercise. Wildlife Research 25, 147–155.
An analysis of bait-take and non-target impacts during a fox-control exercise.Crossref | GoogleScholarGoogle Scholar |

Doherty, TS, Glen, AS, Nimmo, DG, Ritchie, EG, and Dickman, CR (2016). Invasive predators and global biodiversity loss. Proceedings of the National Academy of Sciences 113, 11261–11265.
Invasive predators and global biodiversity loss.Crossref | GoogleScholarGoogle Scholar |

Edwards, D (1998). Issues and themes for natural resources trend and change detection. Ecological Applications 8, 323–325.

Efford, MG (2019). Non-circular home ranges and the estimation of population density. Ecology 100, e02580.
Non-circular home ranges and the estimation of population density.Crossref | GoogleScholarGoogle Scholar |

Engeman, RM (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 |

Falcy, MR, McCormick, JL, and Miller, SA (2016). Proxies in practice: calibration and validation of multiple indices of animal abundance. Journal of Fish and Wildlife Management 7, 117–128.
Proxies in practice: calibration and validation of multiple indices of animal abundance.Crossref | GoogleScholarGoogle Scholar |

Field, SA, Tyre, AJ, Thorn, KH, O’Connor, PJ, and Possingham, HP (2005). Improving the efficiency of wildlife monitoring by estimating detectability: a case study of foxes (Vulpes vulpes) on the Eyre Peninsula, South Australia. Wildlife Research 32, 253–258.
Improving the efficiency of wildlife monitoring by estimating detectability: a case study of foxes (Vulpes vulpes) on the Eyre Peninsula, South Australia.Crossref | GoogleScholarGoogle Scholar |

Fiske, I, and Chandler, R (2011). unmarked: an R package for fitting hierarchical models of wildlife occurrence and abundance. Journal of Statistical Software 43, 1–23.
unmarked: an R package for fitting hierarchical models of wildlife occurrence and abundance.Crossref | GoogleScholarGoogle Scholar |

Gelman, A, and Rubin, DB (1992). Inference from iterative simulation using multiple sequences. Statistical Science 7, 457–472.
Inference from iterative simulation using multiple sequences.Crossref | GoogleScholarGoogle Scholar |

Gentle MN (2005) Factors affecting the efficiency of Fox (Vulpes vulpes) baiting practices on the Central Tablelands of New South Wales. PhD Thesis, University of Sydney, NSW, Australia.

Gentle, M, Massei, G, and Saunders, G (2004). Levamisole can reduce bait monopolization in wild red foxes Vulpes vulpes. Mammal Review 34, 325–330.
Levamisole can reduce bait monopolization in wild red foxes Vulpes vulpes.Crossref | GoogleScholarGoogle Scholar |

Gerber, BD, and Parmenter, RR (2015). Spatial capture–recapture model performance with known small-mammal densities. Ecological Applications 25, 695–705.
Spatial capture–recapture model performance with known small-mammal densities.Crossref | GoogleScholarGoogle Scholar |

Gil-Fernández, M, Harcourt, R, Towerton, A, Newsome, T, Milner, HA, Sriram, S, Gray, N, Escobar-Lasso, S, Gonzalez-Cardoso, VH, and Carthey, A (2021). The canid pest ejector challenge: controlling urban foxes while keeping domestic dogs safe. Wildlife Research 48, 314–322.
The canid pest ejector challenge: controlling urban foxes while keeping domestic dogs safe.Crossref | GoogleScholarGoogle Scholar |

Gopalaswamy, AM, Delampady, M, Karanth, KU, Kumar, NS, Macdonald, DW, and Yoccoz, N (2015). An examination of index-calibration experiments: counting tigers at macroecological scales. Methods in Ecology and Evolution 6, 1055–1066.
An examination of index-calibration experiments: counting tigers at macroecological scales.Crossref | GoogleScholarGoogle Scholar |

Greentree, C, Saunders, G, McLeod, L, and Hone, J (2000). Lamb predation and fox control in south-eastern Australia. Journal of Applied Ecology 37, 935–943.
Lamb predation and fox control in south-eastern Australia.Crossref | GoogleScholarGoogle Scholar |

Guthlin, D, Storch, I, and Küchenhoff, H (2014). Is it possible to individually identify red foxes from photographs? Wildlife Society Bulletin 38, 205–210.
Is it possible to individually identify red foxes from photographs?Crossref | GoogleScholarGoogle Scholar |

Hayward, MW, L’Hotellier, F, O’connor, T, Ward-Fear, G, Cathcart, J, Cathcart, T, Stephens, J, Stephens, J, Herman, K, and Legge, S (2012). Reintroduction of bridled nailtail wallabies beyond fences at Scotia Sanctuary – Phase 1. Proceedings of the Linnean Society of New South Wales 134, A27–A37.

Jennelle, CS, Runge, MC, and MacKenzie, DI (2002). The use of photographic rates to estimate densities of tigers and other cryptic mammals: a comment on misleading conclusions. Animal Conservation 5, 119–120.
The use of photographic rates to estimate densities of tigers and other cryptic mammals: a comment on misleading conclusions.Crossref | GoogleScholarGoogle Scholar |

Johnson, DH (2008). In defense of indices: the case of bird surveys. Journal of Wildlife Management 72, 857–868.
In defense of indices: the case of bird surveys.Crossref | GoogleScholarGoogle Scholar |

Jones, JPG (2011). Monitoring species abundance and distribution at the landscape scale. Journal of Applied Ecology 48, 9–13.
Monitoring species abundance and distribution at the landscape scale.Crossref | GoogleScholarGoogle Scholar |

Keever, AC, McGowan, CP, Ditchkoff, SS, Acker, PK, Grand, JB, and Newbolt, CH (2017). Efficacy of N-mixture models for surveying and monitoring white-tailed deer populations. Mammal Research 62, 413–422.
Efficacy of N-mixture models for surveying and monitoring white-tailed deer populations.Crossref | GoogleScholarGoogle Scholar |

Kreplins, TL, Kennedy, MS, Dundas, SJ, Adams, PJ, Bateman, PW, and Fleming, PA (2018). Corvid interference with canid pest ejectors in the southern rangelands of Western Australia. Ecological Management & Restoration 19, 169–172.
Corvid interference with canid pest ejectors in the southern rangelands of Western Australia.Crossref | GoogleScholarGoogle Scholar |

Legge, S, Woinarski, JCZ, Burbidge, AA, Palmer, R, Ringma, J, Radford, JQ, Mitchell, N, Bode, M, Wintle, B, Baseler, M, Bentley, J, Copley, P, Dexter, N, Dickman, CR, Gillespie, GR, Hill, B, Johnson, CN, Latch, P, Letnic, M, Manning, A, McCreless, EE, Menkhorst, P, Morris, K, Moseby, K, Page, M, Pannell, D, and Tuft, K (2018). Havens for threatened Australian mammals: the contributions of fenced areas and offshore islands to the protection of mammal species susceptible to introduced predators. Wildlife Research 45, 627–644.
Havens for threatened Australian mammals: the contributions of fenced areas and offshore islands to the protection of mammal species susceptible to introduced predators.Crossref | GoogleScholarGoogle Scholar |

Link, WA, Schofield, MR, Barker, RJ, and Sauer, JR (2018). On the robustness of N-mixture models. Ecology 99, 1547–1551.
On the robustness of N-mixture models.Crossref | GoogleScholarGoogle Scholar |

Mahon, PS (2009). Targeted control of widespread exotic species for biodiversity conservation: the Red Fox (Vulpes vulpes) in New South Wales, Australia. Ecological Management & Restoration 10, S59–S69.
Targeted control of widespread exotic species for biodiversity conservation: the Red Fox (Vulpes vulpes) in New South Wales, Australia.Crossref | GoogleScholarGoogle Scholar |

Marks, CA, and Wilson, R (2005). Predicting mammalian target-specificity of the M-44 ejector in south-eastern Australia. Wildlife Research 32, 151–156.
Predicting mammalian target-specificity of the M-44 ejector in south-eastern Australia.Crossref | GoogleScholarGoogle Scholar |

Marlow, NJ, Thomas, ND, Williams, AAE, Macmahon, B, Lawson, J, Hitchen, Y, Angus, J, and Berry, O (2015). Lethal 1080 baiting continues to reduce European Red Fox (Vulpes vulpes) abundance after more than 25 years of continuous use in south-west Western Australia. Ecological Management & Restoration 16, 131–141.
Lethal 1080 baiting continues to reduce European Red Fox (Vulpes vulpes) abundance after more than 25 years of continuous use in south-west Western Australia.Crossref | GoogleScholarGoogle Scholar |

Marlow, N, Thomson, P, Rose, K, and Kok, N (2016). Compensatory responses by a fox population to artificial density reduction in a rangeland area in Western Australia. Conservation Science Western Austalia 10, 1–10.

Moseby, KE, and Hill, BM (2011). The use of poison baits to control feral cats and red foxes in arid South Australia I. Aerial baiting trials. Wildlife Research 38, 338–349.
The use of poison baits to control feral cats and red foxes in arid South Australia I. Aerial baiting trials.Crossref | GoogleScholarGoogle Scholar |

Moseby KE, Read JL (2014) Using camera traps to compare poison bait uptake by invasive predators and non-target species. In ‘Camera trapping: wildlife management and research’. (Eds P Meek, P Fleming) pp. 131–139. (CSIRO Publishing: Melbourne, Vic., Australia)

Nakashima, Y, Fukasawa, K, and Samejima, H (2018). Estimating animal density without individual recognition using information derivable exclusively from camera traps. Journal of Applied Ecology 55, 735–744.
Estimating animal density without individual recognition using information derivable exclusively from camera traps.Crossref | GoogleScholarGoogle Scholar |

Norouzzadeh, MS, Nguyen, A, Kosmala, M, Swanson, A, Palmer, MS, Packer, C, and Clune, J (2018). Automatically identifying, counting, and describing wild animals in camera-trap images with deep learning. Proceedings of the National Academy of Sciences 115, E5716–E5725.
Automatically identifying, counting, and describing wild animals in camera-trap images with deep learning.Crossref | GoogleScholarGoogle Scholar |

Olsson, M, Wapstra, E, Swan, G, Snaith, E, Clarke, R, and Madsen, T (2005). Effects of long-term fox baiting on species composition and abundance in an Australian lizard community. Austral Ecology 30, 899–905.
Effects of long-term fox baiting on species composition and abundance in an Australian lizard community.Crossref | GoogleScholarGoogle Scholar |

Piggott, MP, Wilson, R, Banks, SC, Marks, CA, Gigliotti, F, and Taylor, AC (2008). Evaluating exotic predator control programs using non-invasive genetic tagging. Wildlife Research 35, 617–624.
Evaluating exotic predator control programs using non-invasive genetic tagging.Crossref | GoogleScholarGoogle Scholar |

Plummer, M, Best, N, Cowles, K, and Vines, K (2006). CODA: convergence diagnosis and output analysis for MCMC. R News 6, 7–11.

Pollock, KH, Nichols, JD, Simons, TR, Farnsworth, GL, Bailey, LL, and Sauer, JR (2002). Large scale wildlife monitoring studies: statistical methods for design and analysis. Environmetrics 13, 105–119.
Large scale wildlife monitoring studies: statistical methods for design and analysis.Crossref | GoogleScholarGoogle Scholar |

Porteus, TA, Reynolds, JC, and McAllister, MK (2019). Modelling the rate of successful search of red foxes during population control. Wildlife Research 46, 285–295.
Modelling the rate of successful search of red foxes during population control.Crossref | GoogleScholarGoogle Scholar |

Ramsey, DSL, Caley, PA, and Robley, A (2015). Estimating population density from presence–absence data using a spatially explicit model. The Journal of Wildlife Management 79, 491–499.
Estimating population density from presence–absence data using a spatially explicit model.Crossref | GoogleScholarGoogle Scholar |

R Core Team (2018) R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. Available at https://www.R-project.org/

Robley, A, Gormley, AM, Forsyth, DM, and Triggs, B (2014). Long-term and large-scale control of the introduced red fox increases native mammal occupancy in Australian forests. Biological Conservation 180, 262–269.
Long-term and large-scale control of the introduced red fox increases native mammal occupancy in Australian forests.Crossref | GoogleScholarGoogle Scholar |

Rolls EC (1984) ‘They all ran wild: the animals and plants that plague Australia.’ Revised edn. (Angus & Robertson: Sydney, NSW, Australia)

Roshier, DA, and Carter, A (2021). Space use and interactions of two introduced mesopredators, European red fox and feral cat, in an arid landscape. Ecosphere 12, e03628.
Space use and interactions of two introduced mesopredators, European red fox and feral cat, in an arid landscape.Crossref | GoogleScholarGoogle Scholar |

Roshier, DA, Hotellier, FL, Carter, A, Kemp, L, Potts, J, Hayward, MW, and Legge, SM (2020). Long-term benefits and short-term costs: small vertebrate responses to predator exclusion and native mammal reintroductions in south-western New South Wales, Australia. Wildlife Research 47, 570–579.
Long-term benefits and short-term costs: small vertebrate responses to predator exclusion and native mammal reintroductions in south-western New South Wales, Australia.Crossref | GoogleScholarGoogle Scholar |

Rovero F, Zimmermann F (2016) ‘Camera trapping for wildlife research.’ (Pelagic Publishing: Exeter, UK)

Rowcliffe, JM, Field, J, Turvey, ST, and Carbone, C (2008). Estimating animal density using camera traps without the need for individual recognition. Journal of Applied Ecology 45, 1228–1236.
Estimating animal density using camera traps without the need for individual recognition.Crossref | GoogleScholarGoogle Scholar |

Royle, JA (2004). N-Mixture models for estimating population size from spatially replicated counts. Biometrics 60, 108–115.
N-Mixture models for estimating population size from spatially replicated counts.Crossref | GoogleScholarGoogle Scholar |

Royle JA, Chandler RB, Sollmann R, Gardner B (Eds) (2014) ‘Spatial capture–recapture.’ (Academic Press: Boston, MA, USA)

Ruykys, L, and Carter, A (2019). Removal and eradication of introduced species in a fenced reserve: quantifying effort, costs and results. Ecological Management & Restoration 20, 239–249.
Removal and eradication of introduced species in a fenced reserve: quantifying effort, costs and results.Crossref | GoogleScholarGoogle Scholar |

Sadlier, LMJ, Webbon, CC, Baker, PJ, and Harris, S (2004). Methods of monitoring red foxes Vulpes vulpes and badgers Meles meles: are field signs the answer? Mammal Review 34, 75–98.
Methods of monitoring red foxes Vulpes vulpes and badgers Meles meles: are field signs the answer?Crossref | GoogleScholarGoogle Scholar |

Saunders G, McLeod L (2007) ‘Improving fox management strategies in Australia.’ (Bureau of Rural Sciences: Canberra, ACT, Australia)

Saunders G, Coman B, Kinnear J, Braysher M (1995) ‘Managing vertebrate pests: foxes.’ (Australian Government Publishing Service: Canberra, ACT, Australia)

Schwarz, CJ, and Seber, GAF (1999). Estimating animal abundance: review III. Statistical Science 14, 427–456.
Estimating animal abundance: review III.Crossref | GoogleScholarGoogle Scholar |

Sharp, A, Norton, M, Marks, A, and Holmes, K (2001). An evaluation of two indices of red fox (Vulpes vulpes) abundance in an arid environment. Wildlife Research 28, 419–424.
An evaluation of two indices of red fox (Vulpes vulpes) abundance in an arid environment.Crossref | GoogleScholarGoogle Scholar |

Sollmann, R, Mohamed, A, Samejima, H, and Wilting, A (2013a). Risky business or simple solution – relative abundance indices from camera-trapping. Biological Conservation 159, 405–412.
Risky business or simple solution – relative abundance indices from camera-trapping.Crossref | GoogleScholarGoogle Scholar |

Sollmann, R, Gardner, B, Parsons, AW, Stocking, JJ, McClintock, BT, Simons, TR, Pollock, KH, and O’Connell, AF (2013b). A spatial mark–resight model augmented with telemetry data. Ecology 94, 553–559.
A spatial mark–resight model augmented with telemetry data.Crossref | GoogleScholarGoogle Scholar |

Stephens, PA, Zaumyslova, OY, Miquelle, DG, Myslenkov, AI, and Hayward, GD (2006). Estimating population density from indirect sign: track counts and the Formozov–Malyshev–Pereleshin formula. Animal Conservation 9, 339–348.
Estimating population density from indirect sign: track counts and the Formozov–Malyshev–Pereleshin formula.Crossref | GoogleScholarGoogle Scholar |

Stephens, PA, Pettorelli, N, Barlow, J, Whittingham, MJ, and Cadotte, MW (2015). Management by proxy? The use of indices in applied ecology. Journal of Applied Ecology 52, 1–6.
Management by proxy? The use of indices in applied ecology.Crossref | GoogleScholarGoogle Scholar |

Tabak, MA, Norouzzadeh, MS, Wolfson, DW, Sweeney, SJ, Vercauteren, KC, Snow, NP, Halseth, JM, Di Salvo, PA, Lewis, JS, White, MD, Teton, B, Beasley, JC, Schlichting, PE, Boughton, RK, Wight, B, Newkirk, ES, Ivan, JS, Odell, EA, Brook, RK, Lukacs, PM, Moeller, AK, Mandeville, EG, Clune, J, and Miller, RS (2019). Machine learning to classify animal species in camera trap images: applications in ecology. Methods in Ecology and Evolution 10, 585–590.
Machine learning to classify animal species in camera trap images: applications in ecology.Crossref | GoogleScholarGoogle Scholar |

Thompson, JA, and Fleming, PJS (1994). Evaluation of the efficacy of 1080 poisoning of red foxes using visitation to non-toxic baits as an index of fox abundance. Wildlife Research 21, 27–39.
Evaluation of the efficacy of 1080 poisoning of red foxes using visitation to non-toxic baits as an index of fox abundance.Crossref | GoogleScholarGoogle Scholar |

Thomson, PC, Marlow, NJ, Rose, K, and Kok, NE (2000). The effectiveness of a large-scale baiting campaign and an evaluation of a buffer zone strategy for fox control. Wildlife Research 27, 465–472.
The effectiveness of a large-scale baiting campaign and an evaluation of a buffer zone strategy for fox control.Crossref | GoogleScholarGoogle Scholar |

Towerton, AL, Penman, TD, Kavanagh, RP, and Dickman, CR (2011). Detecting pest and prey responses to fox control across the landscape using remote cameras. Wildlife Research 38, 208–220.
Detecting pest and prey responses to fox control across the landscape using remote cameras.Crossref | GoogleScholarGoogle Scholar |

West P, Saunders G (2007) ‘Pest animal survey: a review of the distribution, impacts and control of invasive animals throughout NSW and the ACT.’ (NSW Department of Primary Industries: Orange, NSW, Australia)

Westbrooke, ME, Miller, JD, and Kerr, MKC (1998). The vegetation of the Scotia 1:100 000 map sheet, western New South Wales. Cunninghamia 5, 665–684.

Whittington, J, Hebblewhite, M, Chandler, RB, and Lentini, P (2018). Generalized spatial mark–resight models with an application to grizzly bears. Journal of Applied Ecology 55, 157–168.
Generalized spatial mark–resight models with an application to grizzly bears.Crossref | GoogleScholarGoogle Scholar |

Woinarski, JCZ, Burbidge, AA, and Harrison, PL (2015). Ongoing unraveling of a continental fauna: decline and extinction of Australian mammals since European settlement. Proceedings of the National Academy of Sciences 112, 4531–4540.
Ongoing unraveling of a continental fauna: decline and extinction of Australian mammals since European settlement.Crossref | GoogleScholarGoogle Scholar |