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

Quantitative analysis of animal-welfare outcomes in helicopter shooting: a case study with feral dromedary camels (Camelus dromedarius)

Jordan O. Hampton A B G , Brendan D. Cowled C , Andrew L. Perry D , Corissa J. Miller A , Bidda Jones E and Quentin Hart F

A Ecotone Wildlife Veterinary Services, PO Box 1126, Canberra, ACT 2601, Australia.

B Murdoch University, 90 South Street, Murdoch, WA 6150, Australia.

C AusVet Animal Health Services, PO Box 1278, Toowoomba, Qld 4350, Australia.

D Kyabram Veterinary Clinic, 77 McCormick Road, Kyabram, Vic. 3620, Australia.

E RSPCA Australia, PO Box 265, Deakin West, ACT 2600, Australia.

F Ninti One Limited, PO Box 3971, Alice Springs, NT 0871, Australia.

G Corresponding author. Email: j.hampton@ecotonewildlife.com

Wildlife Research 41(2) 127-135 http://dx.doi.org/10.1071/WR13216
Submitted: 16 December 2013  Accepted: 2 May 2014   Published: 3 June 2014

Abstract

Context: Helicopter shooting is a common and effective tool for reducing overabundant wildlife populations. However, there is little quantitative information on the humaneness of the method, leading to uncertainty in wildlife-management policy. There is, subsequently, a need for an improved understanding of the welfare implications of helicopter shooting.

Aim: A study was undertaken to infer the humaneness of helicopter shooting for a case study species, the feral dromedary camel (Camelus dromedarius).

Methods: Seven post-mortem studies (n = 715) and one ante-mortem study (n = 192) were undertaken during routine helicopter shooting programs of free-ranging camels. In these studies, we measured four animal-welfare parameters to allow inference on the humaneness of the technique. These parameters were time to death, instantaneous death rate (proportion of animals for which time to death = 0), wounding rate and location of bullet-wound tract. We also modelled these welfare variables against hypothesised explanatory variables to assist improvement of future programs.

Key results: The mean wounding rate was 0.4%, and the killing efficacy of the technique was 99.6%. Mean time to death was 4 s, and mean instantaneous death rate was 83%. Each animal displayed a mean 2.4 bullet-wound tracts, with 75%, 63% and 35% of animals shot at least once in the thorax, cranium and cervical spine, respectively. Regression analysis revealed that the identity of the shooter and the nature of the local vegetation were the most important factors associated with an animal experiencing an inferred instantaneous death or not.

Conclusions: Helicopter shooting of feral camels produces a very low wounding rate and rapid time to death. Shooter identity is the most important consideration for determining animal-welfare outcomes. Improvements to the humaneness of programs can be made by increasing the rigour of shooter selection and training.

Implications: Wildlife killing methods must be demonstrated to be humane to receive public support; however, few shooting methods are objectively examined. Helicopter shooting can be independently examined and operators assessed. Adoption of this examination template may allow continual improvement by industry as well as increasing societal acceptance of helicopter shooting.


References

Ballard, W. B., Franzmann, A. W., and Gardner, C. L. (1982). Comparison and assessment of drugs used to immobilize Alaskan gray wolves (Canis lupus) and wolverines (Gulo gulo) from a helicopter. Journal of Wildlife Diseases 18, 339–342.
Comparison and assessment of drugs used to immobilize Alaskan gray wolves (Canis lupus) and wolverines (Gulo gulo) from a helicopter.CrossRef | 1:CAS:528:DyaL38XlsFKgt7o%3D&md5=bde9bf4e89ab67d7fbfaf59e89fa6b81CAS | 7131656PubMed | open url image1

Barton, K. (2013). ultimodel Inference: Package MuMin (v 1.9.13). The R Project for Statistical Computing.’ Available at http://cran.r-project.org/package=MuMIn [verified 27 March 2014].

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 | open url image1

Ben-Ami, D., Boom, K., Boronyak, L., Townend, C., Ramp, D., Croft, D., and Bekoff, M. (2014). The welfare ethics of the commercial killing of free-ranging kangaroos: an evaluation of the benefits and costs of the industry. Animal Welfare 23, 1–10.
The welfare ethics of the commercial killing of free-ranging kangaroos: an evaluation of the benefits and costs of the industry.CrossRef | 1:CAS:528:DC%2BC2cXisVCjsbo%3D&md5=7c68442d3e6cb6b073dab2f4d6cde257CAS | open url image1

Bradshaw, E. L., and Bateson, P. (2000). Welfare implications of culling red deer (Cervus elaphus). Animal Welfare 9, 3–24. open url image1

Brakes, P., and Donoghue, M. (2006). Comprehensive and standardised data on whale killing: welfare considerations. In ‘Proceedings of the International Whaling Commission Workshop on Whale Killing Methods and Associated Welfare Issues. Number IWC/58/WKM & AWI 7’. pp. 1–4. (International Whaling Commission: Cambridge, UK.) Available at http://archive.iwcoffice.org/_documents/commission/IWC58docs/58-WKM&AWI7.pdf [verified 25 March 2014].

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 | open url image1

Butterworth, A., and Richardson, M. (2013). A review of animal welfare implications of the Canadian commercial seal hunt. Marine Policy 38, 457–469.
A review of animal welfare implications of the Canadian commercial seal hunt.CrossRef | open url image1

Campbell, T. A., and Long, D. B. (2009). Feral swine damage and damage management in forested ecosystems. Forest Ecology and Management 257, 2319–2326.
Feral swine damage and damage management in forested ecosystems.CrossRef | open url image1

Campbell, T. A., Long, D. B., and Leland, B. R. (2010). Feral swine behavior relative to helicopter gunning in southern Texas. The Journal of Wildlife Management 74, 337–341.
Feral swine behavior relative to helicopter gunning in southern Texas.CrossRef | open url image1

Caudell, J. N. (2013). Review of wound ballistic research and its applicability to wildlife management. Wildlife Society Bulletin 37, 824–831.
Review of wound ballistic research and its applicability to wildlife management.CrossRef | open url image1

Causey, K., Kennamer, J. E., Logan, J., and Chapman, J. I. (1978). Bowhunting white-tailed deer with succinylcholine chloride-treated arrows. Wildlife Society Bulletin 6, 142–145. open url image1

Choquenot, D., Hone, J., and Saunders, G. (1999). Using aspects of predator-prey theory to evaluate helicopter shooting for feral pig control. Wildlife Research 26, 251–261.
Using aspects of predator-prey theory to evaluate helicopter shooting for feral pig control.CrossRef | open url image1

Cockram, M. S., Shaw, D. J., Milne, E., Bryce, R., McClean, C., and Daniels, M. J. (2011). Comparison of effects of different methods of culling red deer (Cervus elaphus) by shooting on behaviour and post mortem measurements of blood chemistry, muscle glycogen and carcase characteristics. Animal Welfare (South Mimms, England) 20, 211–224.
| 1:CAS:528:DC%2BC3MXmtFSjt7k%3D&md5=91e5b44b68a3065caa2583dca1be6047CAS | open url image1

Cowled, B. D., Elsworth, P., and Lapidge, S. J. (2008). Additional toxins for feral pig (Sus scrofa) control: identifying and testing Achilles’ heels. Wildlife Research 35, 651–662.
Additional toxins for feral pig (Sus scrofa) control: identifying and testing Achilles’ heels.CrossRef | 1:CAS:528:DC%2BD1cXhtlyjsLjO&md5=76e6ad66e05d89cf76403a2df8d35e30CAS | open url image1

Daoust, P. Y., and Caraguel, C. (2012). The Canadian harp seal hunt: observations on the effectiveness of procedures to avoid poor animal welfare outcomes. Animal Welfare 21, 445–455.
The Canadian harp seal hunt: observations on the effectiveness of procedures to avoid poor animal welfare outcomes.CrossRef | 1:CAS:528:DC%2BC38Xhs1eisLbK&md5=98ea9114d0e8c3b9b95c090130126e1eCAS | open url image1

Daoust, P. Y., Hammill, M., Stenson, G., and Caraguel, C. (2014). A review of animal welfare implications of the Canadian commercial seal hunt: a critique. Marine Policy 43, 367–371.
A review of animal welfare implications of the Canadian commercial seal hunt: a critique.CrossRef | open url image1

Dexter, N. (1996). The effect of an intensive shooting exercise from a helicopter on the behaviour of surviving feral pigs. Wildlife Research 23, 435–441.
The effect of an intensive shooting exercise from a helicopter on the behaviour of surviving feral pigs.CrossRef | open url image1

Di Maio, V. J. M. (1999). ‘Gunshot Wounds: Practical Aspects of Firearms, Ballistics, and Forensic Techniques.’ 2nd edn. (CRC Press: Boca Raton, FL.)

Divljan, A., Parry-Jones, K., and Eby, P. (2011). Deaths and injuries to grey-headed flying-foxes, Pteropus poliocephalus, shot at an orchard near Sydney, New South Wales. Australian Zoologist 35, 698–710.
Deaths and injuries to grey-headed flying-foxes, Pteropus poliocephalus, shot at an orchard near Sydney, New South Wales.CrossRef | open url image1

Dolbeer, R. A., Bernhardt, G. E., Seamans, T. W., and Woronecki, P. P. (1991). Efficacy of two gas cartridge formulations in killing woodchucks in burrows. Wildlife Society Bulletin 19, 200–204. open url image1

Drucker, A. G., Edwards, G. P., and Saalfeld, W. K. (2010). Economics of camel control in central Australia. The Rangeland Journal 32, 117–127.
Economics of camel control in central Australia.CrossRef | open url image1

Edwards, G. P., Eldridge, S. R., Wurst, D., Berman, D. M., and Garbin, V. (2001). Movement patterns of female feral camels in central and northern Australia. Wildlife Research 28, 283–289.
Movement patterns of female feral camels in central and northern Australia.CrossRef | open url image1

Edwards, G. P., Pople, A. R., Saalfeld, K., and Caley, P. (2004a). 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 | open url image1

Edwards, G. P., Saalfeld, K., and Clifford, B. (2004b). Population trend of feral camels in the Northern Territory, Australia. Wildlife Research 31, 509–517.
Population trend of feral camels in the Northern Territory, Australia.CrossRef | open url image1

Edwards, G. P., Zeng, B., Saalfeld, W. K., and Vaarzon-Morel, P. (2010). Evaluation of the impacts of feral camels. The Rangeland Journal 32, 43–54.
Evaluation of the impacts of feral camels.CrossRef | open url image1

Forsyth, D. M., Ramsey, D. S. L., Veltman, C. J., Allen, R. B., Allen, W. J., Barker, R. J., Jacobson, C. L., Nicol, S. J., Richardson, S. J., and Todd, C. R. (2013). When deer must die: large uncertainty surrounds changes in deer abundance achieved by helicopter- and ground-based hunting in New Zealand forests. Wildlife Research 40, 447–458.
When deer must die: large uncertainty surrounds changes in deer abundance achieved by helicopter- and ground-based hunting in New Zealand forests.CrossRef | open url image1

Golden, H. N., Shults, B. S., and Kunkel, K. E. (2002). Immobilization of wolverines with Telazol® from a helicopter. Wildlife Society Bulletin 30, 492–497. open url image1

Grandin, T. (2002). Return-to-sensibility problems after penetrating captive bolt stunning of cattle in commercial beef slaughter plants. Journal of the American Veterinary Medical Association 221, 1258–1261.
Return-to-sensibility problems after penetrating captive bolt stunning of cattle in commercial beef slaughter plants.CrossRef | 12418689PubMed | open url image1

Gregory, N. G. (2005). Bowhunting deer. Animal Welfare 14, 111–116.
| 1:CAS:528:DC%2BD2MXktFKhsLw%3D&md5=f4fe2e143aa04a333359c9109b850b48CAS | open url image1

Grueber, C. E., Nakagawa, S., Laws, R. J., and Jamieson, I. G. (2011). Multimodal inference in ecology and evolution:challenges and solutions. Journal of Evolutionary Biology 24, 699–711.
Multimodal inference in ecology and evolution:challenges and solutions.CrossRef | 1:STN:280:DC%2BC3M3msVeksQ%3D%3D&md5=671fb3b1c1e5cf5f2c4a382e0433541cCAS | 21272107PubMed | open url image1

Hollerman, J. J., Fackler, M. L., Coldwell, D. M., and Ben-Menachem, Y. (1990). Gunshot wounds: 1. Bullets, ballistics, and mechanisms of injury. AJR. American Journal of Roentgenology 155, 685–690.
Gunshot wounds: 1. Bullets, ballistics, and mechanisms of injury.CrossRef | 1:STN:280:DyaK3cznvFSquw%3D%3D&md5=0c29fc780f42b58ca694ee3a75e541abCAS | 2119095PubMed | open url image1

Hone, J. (1990). Predator prey theory and feral pig control, with emphasis on evaluation of shooting from a helicopter. Wildlife Research 17, 123–130.
Predator prey theory and feral pig control, with emphasis on evaluation of shooting from a helicopter.CrossRef | open url image1

Kestin, S. C. (1995). Welfare aspects of the commercial slaughter of whales. Animal Welfare 4, 11–27. open url image1

Knudsen, S. K. (2005). A review of the criteria used to assess insensibility and death in hunted whales compared to other species. Veterinary Journal 169, 42–59.
A review of the criteria used to assess insensibility and death in hunted whales compared to other species.CrossRef | 1:STN:280:DC%2BD2M%2Fls12mtw%3D%3D&md5=78e4290ec5610f6decdb1d908bedb197CAS | open url image1

Knudsen, S. K., and Øen, E. O. (2003). Blast-induced neurotrauma in whales. Neuroscience Research 46, 377–386.
Blast-induced neurotrauma in whales.CrossRef | 12804799PubMed | open url image1

Lewis, A. R., Pinchin, A. M., and Kestin, S. C. (1997). Welfare implications of the night shooting of wild impala (Aepyceros melampus). Animal Welfare 6, 123–131. open url image1

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 | open url image1

Ludders, J. W., Schmidt, R. H., Dein, F. J., and Klein, P. N. (1999). Drowning is not euthanasia. Wildlife Society Bulletin 27, 666–670. open url image1

Marks, C. A. (2009). Fumigation of rabbit warrens with chloropicrin produces poor welfare outcomes: a review. Wildlife Research 36, 342–352.
Fumigation of rabbit warrens with chloropicrin produces poor welfare outcomes: a review.CrossRef | 1:CAS:528:DC%2BD1MXms1agur4%3D&md5=8b44df426d1d9446cde0a02b70f7d437CAS | open url image1

Mellor, D. J., and Littin, K. E. (2004). Using science to support ethical decisions promoting humane livestock slaughter and vertebrate pest control. Animal Welfare 13, 127–132. open url image1

Nieman, D. J., Hochbaum, G. S., Caswell, F. D., and Turner, B. C. (1987). Monitoring hunter performance in prairie Canada. In ‘Transactions of the Fifty-second North American Wildlife and Natural Resources Conference’. pp. 233–245. (Wildlife Management Institute: Quebec City, Canada.)

Nimmo, D. G., and Miller, K. K. (2007). Ecological and human dimensions of the management of feral horses in Australia: a review. Wildlife Research 34, 408–417.
Ecological and human dimensions of the management of feral horses in Australia: a review.CrossRef | open url image1

Noer, H., Madsen, J., and Hartman, P. (2007). Reducing wounding of game by shotgun hunting: effects of a Danish action plan on pink-footed geese. Journal of Applied Ecology 44, 653–662.
Reducing wounding of game by shotgun hunting: effects of a Danish action plan on pink-footed geese.CrossRef | open url image1

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 | open url image1

Pople, A. R., and McLeod, S. R. (2010). Demography of feral camels in central Australia and its relevance to population control. The Rangeland Journal 32, 11–19.
Demography of feral camels in central Australia and its relevance to population control.CrossRef | open url image1

RSPCA Australia (2002). ‘Kangaroo Shooting Code Compliance.’ (RSPCA Australia: Canberra.) Available at http://www.environment.gov.au/biodiversity/wildlife-trade/publications/kangaroo-report/index.html [verified 18 August 2012].

Saunders, G. (1993). Observations on the effectiveness of shooting feral pigs from helicopters. Wildlife Research 20, 771–776.
Observations on the effectiveness of shooting feral pigs from helicopters.CrossRef | open url image1

Saunders, G., Cooke, B., McColl, K., Shine, R., and Peacock, T. (2010). Modern approaches for the biological control of vertebrate pests: an Australian perspective. Biological Control 52, 288–295.
Modern approaches for the biological control of vertebrate pests: an Australian perspective.CrossRef | open url image1

Schulz, J. H., Bonnot, T. W., Millspaugh, J. J., and Mong, T. W. (2013). Harvest and crippling rates of mourning doves in Missouri. Wildlife Society Bulletin 37, 287–292.
Harvest and crippling rates of mourning doves in Missouri.CrossRef | open url image1

Sharp, T. (2010). ‘Standard Operating Procedure CAM002: Aerial Shooting of Camels.’ (Invasive Animals CRC: Canberra.) Available at http://www.feral.org.au/aerial-shooting-of-camels [verified 2 April 2014].

Sharp, T., and Saunders, G. (2011). ‘A Model for Assessing the Relative Humaneness of Pest Animal Control Methods.’ 2nd edn. (Australian Government Department of Agriculture, Fisheries and Forestry: Canberra.)

Smith, R. H., Neff, D. J., and Woolsey, N. G. (1986). Pronghorn response to coyote control: a benefit : cost analysis. Wildlife Society Bulletin 14, 226–231. open url image1

Stewart, C. M., and Veverka, N. B. (2011). The extent of lead fragmentation observed in deer culled by sharpshooting. The Journal of Wildlife Management 75, 1462–1466.
The extent of lead fragmentation observed in deer culled by sharpshooting.CrossRef | open url image1

Stormer, F. A., Kirkpatrick, C. M., and Hoekstra, T. W. (1979). Hunter-inflicted wounding of white-tailed deer. Wildlife Society Bulletin 7, 10–16. open url image1

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.
| 12688447PubMed | open url image1

Tustin, K. G., and Challies, C. N. (1978). The effects of hunting on the numbers and group sizes of Himalayan thar (Hemitragus jemlahicus) in Carneys Creek, Rangitata catchment. New Zealand Journal of Ecology 1, 153–157. open url image1

Urquhart, K. A., and McKendrick, I. J. (2003). Survey of permanent wound tracts in the carcases of culled wild red deer in Scotland. The Veterinary Record 152, 497–501.
Survey of permanent wound tracts in the carcases of culled wild red deer in Scotland.CrossRef | 1:STN:280:DC%2BD3s3ht1aktQ%3D%3D&md5=49e9679493097cd9d2cd4ad8593876fdCAS | 12733558PubMed | open url image1

Urquhart, K. A., and McKendrick, I. J. (2006). Prevalence of ‘head shooting’ and the characteristics of the wounds in culled wild Scottish red deer. The Veterinary Record 159, 75–79.
Prevalence of ‘head shooting’ and the characteristics of the wounds in culled wild Scottish red deer.CrossRef | 1:STN:280:DC%2BD28vitlegsQ%3D%3D&md5=341adb1753972a33800d13eeeff4136dCAS | 16844818PubMed | open url image1

Vaarzon-Morel, P., and Edwards, G. (2012). Incorporating Aboriginal people’s perceptions of introduced animals in resource management: insights from the feral camel project. Ecological Management & Restoration 13, 65–71.
Incorporating Aboriginal people’s perceptions of introduced animals in resource management: insights from the feral camel project.CrossRef | open url image1

Wade, D. A. (1976). The use of aircraft in predator control. In ‘Proceedings of the 7th Vertebrate Pest Conference’. (Ed. C. C. Siebe.) pp. 154–160. (University of California: Davis, CA.)

Warburton, B., Poutu, N., Peters, D., and Waddington, P. (2008). Traps for killing stoats (Mustela erminea): improving welfare performance. Animal Welfare 17, 111–116.
| 1:CAS:528:DC%2BD1cXltFKqtb4%3D&md5=415050044734a16b0696c7d95cf6fa9bCAS | open url image1

Woolnough, A. P., Hampton, J. O., Campbell, S., Lethbridge, M. R., Boardman, W. S., Sharp, T., and Rose, K. (2012). Field immobilization of feral ‘Judas’ donkeys (Equus asinus) by remote injection of medetomidine and ketamine and antagonism with atipamezole. Journal of Wildlife Diseases 48, 435–443.
Field immobilization of feral ‘Judas’ donkeys (Equus asinus) by remote injection of medetomidine and ketamine and antagonism with atipamezole.CrossRef | 1:CAS:528:DC%2BC38XntFOktLo%3D&md5=8867754d3afaab16d7ffff0c595e472aCAS | 22493118PubMed | open url image1



Export Citation