Assessment of animal welfare for helicopter shooting of feral horses
Jordan O. Hampton A H , Glenn P. Edwards B , Brendan D. Cowled C , David M. Forsyth D E , Timothy H. Hyndman A , Andrew L. Perry F , Corissa J. Miller G , Peter J. Adams A and Teresa Collins A
+ Author Affiliations
- Author Affiliations
A Murdoch University, 90 South Street, Murdoch, WA 6150, Australia.
B Department of Land Resource Management, GPO Box 1120, Alice Springs, NT 0871, Australia.
C AusVet Animal Health Services, PO Box 1278, Toowoomba, Qld 4350, Australia.
D University of Melbourne, Parkville, Vic. 3010, Australia.
E Vertebrate Pest Research Unit, Department of Primary Industries, 1447 Forest Road, Orange, NSW 2800, Australia.
F Livestock Extension, PO Box 76, Inverloch, Vic. 3996, Australia.
G Ecotone Wildlife Veterinary Services, PO Box 76, Inverloch, Vic. 3996, Australia.
H Corresponding author. Email: j.hampton@ecotonewildlife.com
Wildlife Research 44(2) 97-105 https://doi.org/10.1071/WR16173
Submitted: 16 September 2016 Accepted: 20 January 2017 Published: 3 March 2017
Abstract
Context: Helicopter shooting is an effective tool for reducing feral horse (Equus caballus) populations that are considered overabundant. However, this tool has been less commonly used in recent years because of concerns about animal-welfare outcomes, which have not previously been quantified.
Aims: The aims of the present study were to assess the helicopter shooting of feral horses to determine (1) the duration of stress, (2) the frequency of adverse animal-welfare events and (3) the influence of explanatory variables in determining welfare outcomes.
Methods: We quantified the welfare outcomes of three helicopter shooting programs in central Australia during 2013 and 2015. We conducted ante-mortem observations of 937 horses and post-mortem observations of 630 horses. We measured the following three parameters to estimate the duration of stress from pursuit and the mode of death: chase time (CT), time to death (TTD) and total time (TT; CT+TTD). We quantified the frequency of adverse animal-welfare events, namely instantaneous death rate (IDR; percentage of animals for which TTD was zero), the apparent frequency of non-fatal wounding, and the frequency of bullet-wound tracts in different anatomical locations. We investigated the role of explanatory variables in determining whether or not a horse had an inferred instantaneous death.
Key results: For all horses, the median CT was 42 s, the median TTD was 0 s (median TTD for horses not killed instantaneously was 15 s), and median TT was 52 s. At least 1% of horses were non-fatally wounded, IDR was 63% (60–66%), and 3% (2–5%) of horses were not shot in the cranium, neck or thorax. Shooter skill was the most important determinant of whether or not a horse had an instantaneous death.
Conclusions: The animal-welfare outcomes of helicopter shooting appear to be similar for feral horses and feral camels (Camelus dromedarius), the only other species that has been studied using these methods, and could be refined by improving shooter skill.
Implications: Quantifying animal-welfare outcomes is particularly important for contentious wildlife management techniques. Wildlife managers should integrate the results of welfare studies into decision-making processes rather than excluding contentious techniques from consideration on the basis of perception.
Additional keywords: ethics, human dimensions, invasive species, population control, stress, wildlife management.
References
Aebischer, N. J., Wheatley, C. J., and Rose, H. R. (2014). Factors associated with shooting accuracy and wounding rate of four managed wild deer species in the UK, based on anonymous field records from deer stalkers. PLoS One 9, e109698.| Factors associated with shooting accuracy and wounding rate of four managed wild deer species in the UK, based on anonymous field records from deer stalkers.Crossref | GoogleScholarGoogle Scholar |
Albrecht, G., McMahon, C. R., Bowman, D. M., and Bradshaw, C. J. (2009). Convergence of culture, ecology, and ethics: management of feral swamp buffalo in northern Australia. Journal of Agricultural & Environmental Ethics 22, 361–378.
| Convergence of culture, ecology, and ethics: management of feral swamp buffalo in northern Australia.Crossref | GoogleScholarGoogle Scholar |
Ashley, M. C., and Holcombe, D. W. (2001). Effect of stress induced by gathers and removals on reproductive success of feral horses. Wildlife Society Bulletin 29, 248–254.
Baker, S. E., Sharp, T. M., and Macdonald, D. W. (2016). Assessing animal welfare impacts in the management of European rabbits (Oryctolagus cuniculus), European moles (Talpa europaea) and carrion crows (Corvus corone). PLoS One 11, e0146298.
| Assessing animal welfare impacts in the management of European rabbits (Oryctolagus cuniculus), European moles (Talpa europaea) and carrion crows (Corvus corone).Crossref | GoogleScholarGoogle Scholar |
Barton, K. (2013). Package MuMIn. Model Selection and Model Averaging Based on Information Criteria. R Package Version 1.9.18. Available at https://cran.r-project.org/web/packages/MuMIn/index.html.
Bayne, P., Harden, B., Pines, K., and Taylor, U. (2000). Controlling feral goats by shooting from a helicopter with and without the assistance of ground-based spotters. Wildlife Research 27, 517–523.
| Controlling feral goats by shooting from a helicopter with and without the assistance of ground-based spotters.Crossref | GoogleScholarGoogle Scholar |
Beever, E. A. (2003). Management implications of the ecology of free-roaming horses in semi-arid ecosystems of the western United States. Wildlife Society Bulletin 31, 887–895.
Berman, D. M. (2013). ‘Wild Horse Trapping and Relocation: Tuan and Toolara State Forests 2009 to 2013.’ (Forestry Plantations Queensland: Gympie, Qld.)
Bradshaw, E. L., and Bateson, P. (2000). Welfare implications of culling red deer (Cervus elaphus). Animal Welfare 9, 3–24.
Brook, R. K., Cattet, M., Darimont, C. T., Paquet, P. C., and Proulx, G. (2015). Maintaining ethical standards during conservation crises. Canadian Wildlife Biology and Management 4, 72–79.
Bryan, R. (2001). Humane control of feral horses in central Australia. In ‘Proceedings of the 12th Australian Vertebrate Pest Conference’, Melbourne. pp. 125−129. (Department of Natural Resources and Environment: Melbourne.)
Burnham, K. P., and Anderson, D. R. (2002). ‘Model Selection and Multimodel Inference: a Practical Information–theoretic Approach.’ (Springer-Verlag: New York.)
Burnham, K. P., Anderson, D. R., and Huyvaert, K. P. (2011). AIC model selection and multimodel inference in behavioral ecology: some background, observations, and comparisons. Behavioral Ecology and Sociobiology 65, 23–35.
| AIC model selection and multimodel inference in behavioral ecology: some background, observations, and comparisons.Crossref | GoogleScholarGoogle Scholar |
Carrion, V., Donlan, C. J., Campbell, K., Lavoie, C., and Cruz, F. (2007). Feral donkey (Equus asinus) eradications in the Galapagos. Biodiversity and Conservation 16, 437–445.
| Feral donkey (Equus asinus) eradications in the Galapagos.Crossref | GoogleScholarGoogle Scholar |
Carroll, C. L., and Huntington, P. J. (1988). Body condition scoring and weight estimation of horses. Equine Veterinary Journal 20, 41–45.
| Body condition scoring and weight estimation of horses.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DyaL1c3htFGgsg%3D%3D&md5=69b97446ba65896c6e0536028bd6765fCAS |
Chapple, R. (2005). The politics of feral horse management in Guy Fawkes River National Park, NSW. Australian Zoologist 33, 233–246.
| The politics of feral horse management in Guy Fawkes River National Park, NSW.Crossref | GoogleScholarGoogle Scholar |
Daoust, P. Y., and Cattet, M. (2004). Consideration of the use of the 22 caliber rimfire Winchester magnum cartridge for instant killing of young harp seals (Pagophilus groenlandicus). Research Document 2004/072. Department of Fisheries and Oceans Canadian Science Advisory Secretariat, Ottawa, Canada.
Edwards, G. P., Pople, A. R., Saalfeld, K., and Caley, P. (2004). Introduced mammals in Australian rangelands: future threats and the role of monitoring programmes in management strategies. Austral Ecology 29, 40–50.
| Introduced mammals in Australian rangelands: future threats and the role of monitoring programmes in management strategies.Crossref | GoogleScholarGoogle Scholar |
Edwards, G., Digby, D., O’Leary, P., Rafferty, D., Jensen, M., Woolnough, A. P., Secomb, N., Williams, M., Schwartzkopff, K., and Bryan, R. (2016). Planning and conducting aerial culling operations for feral camels. The Rangeland Journal 38, 153–162.
| Planning and conducting aerial culling operations for feral camels.Crossref | GoogleScholarGoogle Scholar |
English, A. W. (2000). Report on the cull of feral horses in Guy Fawkes River National Park in October 2000. University of Sydney, Sydney.
Fisher, P., Brown, S., and Arrow, J. (2016). Welfare impacts of pindone poisoning in rabbits (Oryctolagus cuniculus). Animals (Basel) 6, 19–27.
| Welfare impacts of pindone poisoning in rabbits (Oryctolagus cuniculus).Crossref | GoogleScholarGoogle Scholar |
Fox, N. C., Blay, N., Greenwood, A. G., Wise, D., and Potapov, E. (2005). Wounding rates in shooting foxes (Vulpes vulpes). Animal Welfare (South Mimms, England) 14, 93–102.
| 1:CAS:528:DC%2BD2MXktFKhsL4%3D&md5=6bbe089fdb62c7994b3731a1b3cb418eCAS |
Garrott, R. A., and Oli, M. K. (2013). A critical crossroad for BLM’s wild horse program. Science 341, 847–848.
| A critical crossroad for BLM’s wild horse program.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3sXhsVOisr3M&md5=a41c3cd4d946113fee5941c029af7cbfCAS |
Goodloe, R. B., Osborn, D. A., and Hall, C. (2000). Population characteristics of feral horses on Cumberland Island, Georgia and their management implications. The Journal of Wildlife Management 64, 114–121.
| Population characteristics of feral horses on Cumberland Island, Georgia and their management implications.Crossref | GoogleScholarGoogle Scholar |
Gregory, N. G., Lee, C. J., and Widdicombe, J. P. (2007). Depth of concussion in cattle shot by penetrating captive bolt. Meat Science 77, 499–503.
| Depth of concussion in cattle shot by penetrating captive bolt.Crossref | GoogleScholarGoogle Scholar |
Grueber, C. E., Nakagawa, S., Laws, R. J., and Jamieson, I. G. (2011). Multimodel inference in ecology and evolution: challenges and solutions. Journal of Evolutionary Biology 24, 699–711.
| Multimodel inference in ecology and evolution: challenges and solutions.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BC3M3msVeksQ%3D%3D&md5=15077672d6fe4617d6381aa67a7ae142CAS |
Hampson, B. A., Zabek, M. A., Pollitt, C. C., and Nock, B. (2011). Health and behaviour consequences of feral horse relocation. The Rangeland Journal 33, 173–180.
| Health and behaviour consequences of feral horse relocation.Crossref | GoogleScholarGoogle Scholar |
Hampton, J. O., and Forsyth, D. M. (2016). An assessment of animal welfare for the culling of peri-urban kangaroos. Wildlife Research 43, 261–266.
| An assessment of animal welfare for the culling of peri-urban kangaroos.Crossref | GoogleScholarGoogle Scholar |
Hampton, J. O., Cowled, B. D., Perry, A. L., Miller, C. J., Jones, B., and Hart, Q. (2014). A quantitative analysis of animal welfare outcomes in helicopter shooting: a case study with feral dromedary camels (Camelus dromedarius). Wildlife Research 41, 127–145.
| A quantitative analysis of animal welfare outcomes in helicopter shooting: a case study with feral dromedary camels (Camelus dromedarius).Crossref | GoogleScholarGoogle Scholar |
Hampton, J. O., Robertson, H., Adams, P., Hyndman, T. H., and Collins, T. (2016a). An animal welfare assessment framework for helicopter darting: a case study with a newly developed method for feral horses. Wildlife Research 43, 429–437.
| An animal welfare assessment framework for helicopter darting: a case study with a newly developed method for feral horses.Crossref | GoogleScholarGoogle Scholar |
Hampton, J. O., Jones, B., Perry, A. L., Miller, C. J., and Hart, Q. (2016b). Integrating animal welfare into wild herbivore management: lessons from the Australian Feral Camel Management Project. The Rangeland Journal 38, 163–171.
| Integrating animal welfare into wild herbivore management: lessons from the Australian Feral Camel Management Project.Crossref | GoogleScholarGoogle Scholar |
Hampton, J. O., Adams, P., Forsyth, D. M., Cowled, B. D., Stuart, I. G., Hyndman, T. H., and Collins, T. (2016c). Improving animal welfare in wildlife shooting: the importance of projectile energy. Wildlife Society Bulletin 40, 678–686.
Henneke, D. R., Potter, G. D., Kreider, J. L., and Yeates, B. F. (1983). Relationship between body condition score, physical measurements and body fat percentages in mares. Equine Veterinary Journal 15, 371–372.
| Relationship between body condition score, physical measurements and body fat percentages in mares.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DyaL2c%2FlslKltg%3D%3D&md5=8a14bd1b8f8b0e544a1a5d4deec3cd05CAS |
Jacques, C. N., Jenks, J. A., Deperno, C. S., Sievers, J. D., Grovenburg, T. W., Brinkman, T. J., Swanson, C. C., and Stillings, B. A. (2009). Evaluating ungulate mortality associated with helicopter net‐gun captures in the northern Great Plains. The Journal of Wildlife Management 73, 1282–1291.
| Evaluating ungulate mortality associated with helicopter net‐gun captures in the northern Great Plains.Crossref | GoogleScholarGoogle Scholar |
Kaplan, E. L., and Meier, P. (1958). Nonparametric estimation from incomplete observations. Journal of the American Statistical Association 53, 457–481.
| Nonparametric estimation from incomplete observations.Crossref | GoogleScholarGoogle Scholar |
Kestin, S. C. (1995). Welfare aspects of the commercial slaughter of whales. Animal Welfare 4, 11–27.
Linklater, W. L., and Cameron, E. Z. (2002). Escape behaviour of feral horses during a helicopter count. Wildlife Research 29, 221–224.
| Escape behaviour of feral horses during a helicopter count.Crossref | GoogleScholarGoogle Scholar |
Littin, K. E., O’Connor, C. E., Gregory, N. G., Mellor, D. J., and Eason, C. T. (2002). Behaviour, coagulopathy and pathology of brushtail possums (Trichosurus vulpecula) poisoned with brodifacoum. Wildlife Research 29, 259–267.
| Behaviour, coagulopathy and pathology of brushtail possums (Trichosurus vulpecula) poisoned with brodifacoum.Crossref | GoogleScholarGoogle Scholar |
McCann, McCann, McCann, (2016). Efficacy of non-lead ammunition for culling elk at Theodore Roosevelt National Park. Human-Wildlife Interactions 10, 268–282.
Nimmo, D. G., and Miller, K. K. (2007). Ecological and human dimensions of management of feral horses in Australia: a review. Wildlife Research 34, 408–417.
| Ecological and human dimensions of management of feral horses in Australia: a review.Crossref | GoogleScholarGoogle Scholar |
Nimmo, D. G., Miller, K. K., and Adams, R. (2007). Managing feral horses in Victoria: a study of community attitudes and perceptions. Ecological Management & Restoration 8, 237–243.
| Managing feral horses in Victoria: a study of community attitudes and perceptions.Crossref | GoogleScholarGoogle Scholar |
Parker, H., Rosell, F., and Danielsen, J. (2006). Efficacy of cartridge type and projectile design in the harvest of beaver. Wildlife Society Bulletin 34, 127–130.
| Efficacy of cartridge type and projectile design in the harvest of beaver.Crossref | GoogleScholarGoogle Scholar |
Ponjoan, A., Bota, G., Morena, E. G. D., Morales, M. B., Wolff, A., Marco, I., and Mañosa, S. (2008). Adverse effects of capture and handling little bustard. The Journal of Wildlife Management 72, 315–319.
| Adverse effects of capture and handling little bustard.Crossref | GoogleScholarGoogle Scholar |
Rogers, G. M. (1991). Kaimanawa feral horses and their environmental impacts. New Zealand Journal of Ecology 15, 49–64.
Rostal, M. K., Evans, A. L., Solberg, E. J., and Arnemo, J. M. (2012). Hematology and serum chemistry reference ranges of free-ranging moose (Alces alces) in Norway. Journal of Wildlife Diseases 48, 548–559.
| Hematology and serum chemistry reference ranges of free-ranging moose (Alces alces) in Norway.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38Xht1Gju7fL&md5=0cc9afd544e2d4ef9ff82b67a2793da6CAS |
Sharp, T. (2010). ‘Standard Operating Procedure CAM002: Aerial Shooting of Camels.’ (Invasive Animals CRC: Canberra.)
Sharp, T. (2011a). ‘Standard Operating Procedure HOR002: Aerial Shooting of Feral Horses.’ (Invasive Animals CRC: Canberra.)
Sharp, T. (2011b). ‘Standard Operating Procedure HOR001: Ground Shooting of Feral Horses.’ (Invasive Animals CRC: Canberra.)
Tharion, W. J., Shukitt-Hale, B., and Lieberman, H. R. (2003). Caffeine effects on marksmanship during high-stress military training with 72 hour sleep deprivation. Aviation, Space, and Environmental Medicine 74, 309–314.
Turner, J. W., Rutberg, A. T., Naugle, R. E., Kaur, M. A., Flanagan, D. R., Bertschinger, H. J., and Liu, I. K. (2008). Controlled release components of PZP contraceptive vaccine extend duration of infertility. Wildlife Research 35, 555–562.
| Controlled release components of PZP contraceptive vaccine extend duration of infertility.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXht1KrtLbL&md5=e52c16b953542c1a9aef40026c640f20CAS |
Ward, L., Lindsey, S., Martin, J. M., Nicodemus, M., and Memili, E. (2016). Challenges and opportunities in rising feral horse populations. The Professional Animal Scientist 32, 717–724.
Zabek, M. A., Wright, J., Berman, D., Hampton, J. O., and Collins, C. W. (2014). Assessing the efficacy of medetomidine and tiletamine-zolazepam for remote immobilisation of feral horses (Equus caballus). Wildlife Research 41, 615–622.
| Assessing the efficacy of medetomidine and tiletamine-zolazepam for remote immobilisation of feral horses (Equus caballus).Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC2MXltFehsr0%3D&md5=e96c076d5ce3c35808f3c685a5f8576cCAS |
Zabek, M. A., Berman, D. M., Blomberg, S. P., Collins, C. W., and Wright, J. (2016). Population dynamics of feral horses (Equus caballus) in an exotic coniferous plantation in Australia. Wildlife Research 43, 358–367.
| Population dynamics of feral horses (Equus caballus) in an exotic coniferous plantation in Australia.Crossref | GoogleScholarGoogle Scholar |
Zalba, S. M., and Cozzani, N. C. (2004). The impact of feral horses on grassland bird communities in Argentina. Animal Conservation 7, 35–44.
| The impact of feral horses on grassland bird communities in Argentina.Crossref | GoogleScholarGoogle Scholar |
