Justice for animals requires controlling invasive species

feral horses

Feral horse control in sensitive alpine environments has been stymied by animal welfare concerns, ignoring the welfare and conservation impacts on other species. Photo: Bill Kosky

If you care about wildlife, the Animal Justice Party (AJP) has some strong election policies.[1] But aspects of their policies relevant to invasive species are poor for both animal welfare and conservation. The AJP policy on introduced animals downplays the great damage they cause, and their policy on feral horses completely neglects the welfare of native animals harmed by horse damage.

I critique some of the AJP policies here – because it is election time and because a party that cares deeply about wildlife should be strong advocates for effective control of damaging invasive species.

Invasive species – particularly foxes and cats, but also rats, rabbits and chytrid fungus – have been the greatest cause of animal extinctions in Australia since European colonisation.[2] This hasn’t changed in recent times – an analysis by Tim Low of the 14 or so animal extinctions in the past 50 years shows that invasive species are still the primary cause.[3]

The Animal Justice Party is wrong in saying that that ‘anthropogenic climate disruption and changes in land use, resulting in habitat loss, are now the major contributors to species loss’. Although it may change in future as global warming intensifies, invasive species currently threaten manyfold more Australian species than climate change. A 2011 analysis by Megan Evans and colleagues found that habitat loss, introduced species and inappropriate fire regimes are the top three threats to nationally listed threatened species.[4] Introduced species (plants and animals) threaten more than three-quarters of listed mammals, birds and amphibians and more than two-thirds of listed fish and reptiles.

Threat category % threatened species (in 2008) threatened
Habitat loss 81%
Introduced plants and animals 61%
Inappropriate fire regimes 43%
Overexploitation 20%
Disease 15%
Natural causes 15%
Native species interactions 15%
Pollution 14%

In its policy on koalas, the Animal Justice Party expresses concern about the survival of koalas and advocates strong conservation measures (including feral dog control) but their policy on introduced species advises that we need to keep ‘widely reported “damage” of introduced species in perspective’ and acknowledge that ‘extinction of species is not a new phenomenon’. Why focus on preventing extinction of koalas and not on averting extinction threats to hundreds of other species due to foxes, cats, goats, pigs, rats etcetera? In its policy on birds, the AJP focuses mostly on habitat threats and doesn’t mention that invasive animals are also a major problem, particularly for island birds. The AJP preference to ban all poisons would mean that rats would still be preying on seabird chicks on Macquarie Island and rabbits would still be destroying their habitat.  Immunocontraceptive techniques, advocated by the AJP as a replacement for biological and chemical control does not currently offer any viable control options, and ‘it is highly unlikely that this will change in the foreseeable future’ according to a review.[5]

The threat of invasive species is not just to species survival – it is also an animal welfare problem. Individual animals can suffer great distress and slow deaths from predation, competition and degradation caused by invasive species. The numbers of native animals suffering from the impacts of invasive species would greatly exceed the numbers of introduced animals that suffer from control.

There is no mention of any native wildlife in the AJP policy on feral horses (‘heritage brumbies’). What about the welfare impacts on native wildlife due to horse damage to waterholes and destruction of food resources and degradation?

As heavy hooved animals, feral horses cause great damage to alpine environments. Photo: Bill Kosky

As heavy hooved animals, feral horses cause great damage to alpine environments. Photo: Bill Kosky

There is growing alarm in the conservation community about damage caused by burgeoning populations of feral horses in sensitive alpine environments. After considering all the options, the Invasive Species Council believes that the only effective and the most humane control method is aerial shooting by highly skilled professional shooters. No other method can achieve even stabilisation of feral horse numbers, and methods currently used – ground mustering and removal – are also highly stressful for horses.

Two helicopters should be used for aerial shooting, the second one following the first to verify the death of shot horses. A welfare assessment of aerial shooting of feral horses on a property in the Northern Territory (3500 were shot in May) was reported by the ABC as having obtained the following results:[6]

  • average time to death was 8 seconds
  • 58 per cent of 2000 assessed horses died instantaneously
  • the wounding rate was zero
  • the average pursuit time (measured from when horses first respond to the sound of helicopters) was 73 seconds

In ISC’s submission recently to the Victorian government on feral horse control in the alpine park, we summed it up in the following way:

We believe that overall an effective aerial shooting program will provide the best animal welfare outcomes. There will be more suffering in the future if much larger numbers of feral horses have to be killed and when they starve because of over-population. We must be equally concerned about the welfare of the many more native animals adversely affected by feral horses. To minimise the numbers killed over time, initial efforts should aim for a large reduction of numbers over a short period of time.

We strongly agree with the Animal Justice Party that Australians should respect introduced animals as sentient beings and be concerned about their welfare. There is definitely need for more research on humane control methods and a focus on preventing suffering in control programs. But respecting native wildlife as sentient beings – and respecting their existence as species (a high proportion endemic to Australia) – requires acknowledging the great damage caused by invasive species and supporting effective control programs.

References

[1] animaljusticeparty.org

[2] Invasive Species Council. 2009. Invasive species: One of the top three threats to Australian biodiversity. invasives.org.au%2Fdocuments%2Ffile%2Fbackgrounders%2FBgrnder-invasivespeciesthreats.pdf

[3] Low T. 2013. 50 years of extinction. Wildlife Australia, in press.

[4] Evans M, Watson J, Fuller R, Venter O, Bennetts, Marsack P, Possingham H. 2011. The spatial distribution of threats to species in Australia. BioScience 61:281-289.

[5] McLeod S, Saunders G, Twigg L, Arthur A, Ramey D, Hinds L. 2007. Prospects for the future: is there a role for virally vectored immunocontraception in vertebrate pest management? Wildlife Research 34: 555–566

[6] abc.net.au/news/2013-08-13/animal-welfare-horse-culling/4873726


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