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

The animal welfare impacts of a gas explosive device used for the management of wild rabbits in Australia

T. M. Sharp https://orcid.org/0000-0003-1160-470X A * and S. R. McLeod https://orcid.org/0000-0003-2932-2727 A
+ Author Affiliations
- Author Affiliations

A Vertebrate Pest Research Unit, Forest Road, NSW Department of Primary Industries, Orange, NSW 2800, Australia.

* Correspondence to: trudy.sharp@dpi.nsw.gov.au

Handling Editor: Penny Fisher

Wildlife Research 49(5) 464-476 https://doi.org/10.1071/WR21111
Submitted: 22 July 2021  Accepted: 8 November 2021   Published: 3 March 2022

© 2022 The Author(s) (or their employer(s)). Published by CSIRO Publishing.

Abstract

Context: Destruction of rabbit warrens to prevent re-invasion is an important component of integrated rabbit management. Ripping, and less commonly blasting with explosives, are used to destroy warren systems and to kill any rabbits remaining in warrens, usually after the population has already been reduced. However, the use of these methods can sometimes be constrained by vegetation, topography, presence of culturally significant sites or important habitats, or they may be inefficient or expensive due to the low density of warrens. Gas explosive devices provide an alternative method in these situations; however, little is known about their animal welfare impacts. The R3 Unit is a gas explosive device used in Australia. It pumps a calibrated mixture of propane and oxygen into a warren and then ignites the mixture, causing a blast wave to travel through the warren.

Aims: To determine the animal welfare impacts of the R3 Unit gas explosive device and to assess its effectiveness at achieving a rapid death in wild rabbits.

Methods: Trials of the R3 Unit were initially conducted in artificial warrens to determine the relationship between blast pressure, warren size and structure. We then assessed the extent of injury and probability of death of rabbits in both artificial and natural warrens.

Key results: As blast pressure increases within a warren, probability of death also increases. Blast pressures exceeding 56 psi will render rabbits unconscious, but a blast pressure of at least 67 psi is required to kill rabbits quickly and humanely. Sublethal blasts at lower pressures result in significant injuries that lead to severe suffering.

Conclusions: The R3 Unit can humanely kill rabbits when the blast pressure is sufficient to cause immediate unconsciousness and death (without regaining consciousness). To achieve adequate blast pressure, warrens must be small, with a diameter no more than 4 m, and all entrances must be sealed.

Implications: The R3 Unit can provide an effective alternative to warren ripping and blasting in certain situations. However, to ensure the device is used correctly to minimise animal welfare impacts, operators must be trained in its use and follow best practice procedures.

Keywords: animal welfare, gas explosive device, humaneness, LPG device, pest management, rabbit management, rabbit populations, Rodenator, wild rabbits.


References

Abrantes, J, Loo, W, van der, Pendu, JL, and Esteves, PJ (2012). Rabbit haemorrhagic disease (RHD) and rabbit haemorrhagic disease virus (RHDV): a review. Veterinary Research 43, 12.
Rabbit haemorrhagic disease (RHD) and rabbit haemorrhagic disease virus (RHDV): a review.Crossref | GoogleScholarGoogle Scholar | 22325049PubMed |

Australian Organic (2019) Australian Certified Organic: Standard. V.1. Available at https://www.aco.net.au/Downloads/ACOS_2019_V1.pdf [Accessed 24 January 2022]​

Berman, D, Brennan, M, and Elsworth, P (2011). How can warren destruction by ripping control European wild rabbits (Oryctolagus cuniculus) on large properties in the Australian arid zone? Wildlife Research 38, 77–88.
How can warren destruction by ripping control European wild rabbits (Oryctolagus cuniculus) on large properties in the Australian arid zone?Crossref | GoogleScholarGoogle Scholar |

Burnham KP, Anderson DR (2002) ‘Model Selection and Multimodel Inference.’ (Springer: New York, NY)

Centers for Disease Control and Prevention (2006) ‘Explosions and Blast Injuries. A Primer for Clinicians.’ (Centers for Disease Control and Prevention: Atlanta, GA) Available at https://www.cdc.gov/masstrauma/preparedness/primer.pdf [Accessed 4 July 2021]

Chaloner, E (2005). Blast injury in enclosed spaces. BMJ 331, 119–120.
Blast injury in enclosed spaces.Crossref | GoogleScholarGoogle Scholar | 16009670PubMed |

Commonwealth of Australia (2016) ‘Background document: Threat Abatement Plan for Competition and Land Degradation by Rabbits.’ (Commonwealth of Australia: Canberra)

Cooke, BD (2012a). Rabbits: manageable environmental pests or participants in new Australian ecosystems? Wildlife Research 39, 279–289.
Rabbits: manageable environmental pests or participants in new Australian ecosystems?Crossref | GoogleScholarGoogle Scholar |

Cooke BD (2012b) ‘Planning Landscape-scale Rabbit Control.’ PestSmart Toolkit Publication. (Invasive Animals Cooperative Research Centre: Canberra, ACT, Australia)

Cooper, GJ, Maynard, RL, Cross, NL, and Hill, JF (1983). Casualties from terrorist bombings. The Journal of Trauma 23, 955–967.
Casualties from terrorist bombings.Crossref | GoogleScholarGoogle Scholar | 6632027PubMed |

de Candole, CA (1967). Blast Injury. Canadian Medical Association Journal 96, 207–214.
| 6015742PubMed |

DEFRA (2007) ‘Defra Position Statement on Rodenator and Similar Devices.’ (Department for Environment, Food and Rural Affairs)

Edwards, GP, Dobbie, W, and Berman, DM (2002). Warren ripping: its impacts on European rabbits and other wildlife of central Australia amid the establishment of rabbit haemorrhagic disease. Wildlife Research 29, 567–575.
Warren ripping: its impacts on European rabbits and other wildlife of central Australia amid the establishment of rabbit haemorrhagic disease.Crossref | GoogleScholarGoogle Scholar |

Eldridge, DJ, and Myers, CA (2001). The impact of warrens of the European rabbit (Oryctolagus cuniculus L.) on soil and ecological processes in a semi-arid Australian woodland. Journal of Arid Environments 47, 325–337.
The impact of warrens of the European rabbit (Oryctolagus cuniculus L.) on soil and ecological processes in a semi-arid Australian woodland.Crossref | GoogleScholarGoogle Scholar |

Eldridge, DJ, and Simpson, R (2002). Rabbit (Oryctolagus cuniculus L.) impacts on vegetation and soils, and implications for management of wooded rangelands. Basic and Applied Ecology 3, 19–29.
Rabbit (Oryctolagus cuniculus L.) impacts on vegetation and soils, and implications for management of wooded rangelands.Crossref | GoogleScholarGoogle Scholar |

Grandin T (2002) ‘AMI Meat Institute Foundation: Good Management Practices for Animal Handling and Stunning’, 2nd edn. (American Meat Institute Foundation: Washington, DC)

Heydon, MJ, Wilson, CJ, and Tew, T (2010). Wildlife conflict resolution: a review of problems, solutions and regulation in England. Wildlife Research 37, 731–748.
Wildlife conflict resolution: a review of problems, solutions and regulation in England.Crossref | GoogleScholarGoogle Scholar |

Kelderer M, Casera C (2008) The “Rodenator”: an efficient device for controlling field mice and root voles? In ‘Ecofruit. 13th International Conference on Cultivation Technique and Phytopathological Problems in Organic Fruit-Growing’, 18–20 February 2008, Weinsberg, Germany. pp. 335–338. (Ecofruit: Weinsberg, Germany)

Kolb, HH (1985). The burrow structure of the European rabbit (Oryctolagus cuniculus L.). Journal of Zoology 206, 253–262.
The burrow structure of the European rabbit (Oryctolagus cuniculus L.).Crossref | GoogleScholarGoogle Scholar |

Leibovici, DMD, Gofrit, ONMD, Stein, MMD, Shapira, SCMD, Noga, YMD, Heruti, RJMD, and Shemer, JMD (1996). Blast injuries: bus versus open-air bombings–a comparative study of injuries in survivors of open-air versus confined-space explosions. Journal of Trauma-Injury Infection & Critical Care 41, 1030–1035.

Leibovici, D, Gofrit, ON, and Shapira, SC (1999). Eardrum perforation in explosion survivors: is it a marker of pulmonary blast injury? Annals of Emergency Medicine 34, 168–172.
Eardrum perforation in explosion survivors: is it a marker of pulmonary blast injury?Crossref | GoogleScholarGoogle Scholar | 10424917PubMed |

Mach JJ (2004) ‘Evaluation of the Rodenator Pro (TM) on European rabbits (Oryctolagus cuniculus).’ (Genesis Laboratories, Inc.)

Mayo, A, and Kluger, Y (2006). Blast-induced injury of air-containing organs. ADF Health 7, 40–44.

Mazerolle MJ (2020) AICcmodavg: model selection and multimodel inference based on (Q)AIC(c). Manual. Available at https://cran.r-project.org/package=AICcmodavg

McIlroy JC (1992) The effect on Australian animals of 1080-poisoning campaigns. In ‘Proceedings of the 15th Vertebrate Pest Conference’. (Eds JE Borrecco, RE March) (University of California: Davis, CA)

McIlroy, JC, and Gifford, EJ (1992). Secondary poisoning hazards associated with 1080-treated carrot-baiting campaigns against rabbits, Ooryctolagus cuniculus. Wildlife Research 19, 629–641.
Secondary poisoning hazards associated with 1080-treated carrot-baiting campaigns against rabbits, Ooryctolagus cuniculus.Crossref | GoogleScholarGoogle Scholar |

Meyer Industries (2011) Rodenator R3 operator’s manual. Available at http://rodenator.eu/user-guides [Accessed 19 June 2021]

Mutze, GJ (1991). Long-term effects of warren ripping for rabbit control in semi-arid South Australia. The Rangeland Journal 13, 96–106.
Long-term effects of warren ripping for rabbit control in semi-arid South Australia.Crossref | GoogleScholarGoogle Scholar |

Parer, I, Fullagar, PJ, and Malafant, KWJ (1987). The history and structure of a large warren of the rabbit, Oryctolagus cuniculus, at Canberra, ACT. Wildlife Research 14, 505–513.
The history and structure of a large warren of the rabbit, Oryctolagus cuniculus, at Canberra, ACT.Crossref | GoogleScholarGoogle Scholar |

Parker, BS (1977). The distribution and density of rabbit warrens on the Southern Tablelands of New South Wales. Australian Journal of Ecology 2, 329–340.
The distribution and density of rabbit warrens on the Southern Tablelands of New South Wales.Crossref | GoogleScholarGoogle Scholar |

PCB Piezonelectronics (undated). Model 113B21ICP® pressure sensor installation and operating manual. Available at https://www.pcb.com/contentstore/docs/PCB_Corporate/Pressure/Products/Manuals/113B21.pdf [Accessed 4 July 2021]

Rafaels, KA, ‘Dale’ Bass, CR, Panzer, MB, Salzar, RS, Woods, WA, Feldman, SH, Walilko, T, Kent, RW, Capehart, BP, Foster, JB, Derkunt, B, and Toman, A (2012). Brain injury risk from primary blast. Journal of Trauma and Acute Care Surgery 73, 895–901.
Brain injury risk from primary blast.Crossref | GoogleScholarGoogle Scholar |

Ramsey, DSL, McPhee, SR, Forsyth, DM, Stuart, IG, Scroggie, MP, Lindeman, M, and Matthews, J (2014). Recolonisation of rabbit warrens following coordinated ripping programs in Victoria, south-eastern Australia. Wildlife Research 41, 46–55.
Recolonisation of rabbit warrens following coordinated ripping programs in Victoria, south-eastern Australia.Crossref | GoogleScholarGoogle Scholar |

R Core Team (2021) R: A language and environment for statistical computing. Manual. Vienna, Austria. Available at https://www.R-project.org/

Sharp TM (2012) Rabbit warren destruction using explosives. Standard operating procedure. Available at https://pestsmart.org.au/toolkit-resource/rabbit-warren-destruction-using-explosives/ [Accessed 16 June 2021]

Sharp TM, Saunders G (2012) Code of practice for the humane control of rabbits. Model codes of practice. Available at https://pestsmart.org.au/toolkit-resource/code-of-practice-rabbits/ [Accessed 11 June 2021]

Sharp TM, Cope H, Saunders G (in press) ‘Code of Practice and Standard Operating Procedures for the Effective and Humane Management of Rabbits.’ (NSW Department of Primary Industries: Orange, NSW)

Stuhmiller JH (2008) ‘Blast Injury: Translating Research into Operational Medicine.’ (Office of The Surgeon General at TMM Publications, Borden Institute, Walter Reed Army Medical Center)

Sullins M, Sullivan D (1992) Observations of a gas exploding device for controlling burrowing rodents. In ‘Proceedings of the 15th Vertebrate Pest Conference 1992, Newport  Beach, California, USA, 3–5 March 1992’​. (Eds JE Borrecco, RE Marsh) (University of California: Davis, CA) Available at http://digitalcommons.unl.edu/vpc15/76 [Accessed 24 January 2022]

Vaughn, L, and Beckel, N (2012). Severe burn injury, burn shock, and smoke inhalation injury in small animals. Part 1: Burn classification and pathophysiology. Journal of Veterinary Emergency and Critical Care 22, 179–186.
Severe burn injury, burn shock, and smoke inhalation injury in small animals. Part 1: Burn classification and pathophysiology.Crossref | GoogleScholarGoogle Scholar | 23016809PubMed |

Wickham H (2016) ‘ggplot2: Elegant Graphics for Data Analysis.’ (Springer-Verlag: New York, NY) Available at https://ggplot2.tidyverse.org

Wightman, JM, and Gladish, SL (2001). Explosions and blast injuries. Annals of Emergency Medicine 37, 664–678.
Explosions and blast injuries.Crossref | GoogleScholarGoogle Scholar | 11385339PubMed |

Williams, C, and Moore, R (1995). Effectiveness and cost-efficiency of control of the wild rabbit, Oryctolagus cuniculus (L.), by combinations of poisoning, ripping, fumigation and maintenance fumigation. Wildllife Research 22, 253–269.
Effectiveness and cost-efficiency of control of the wild rabbit, Oryctolagus cuniculus (L.), by combinations of poisoning, ripping, fumigation and maintenance fumigation.Crossref | GoogleScholarGoogle Scholar |

Williams K, Parer I, Coman B, Burley J, Braysher M (1995) ‘Managing Vertebrate Pests: Rabbits.’ (Australian Government Publishing Service: Canberra, ACT)