Greater death rates for invasive rabbits from interacting diseases

30 05 2018

When it comes to death rates for invasive European rabbits (Oryctolagus cuniculus) in Australia, it appears that 1 + 1 = 2.1.

Pt tagged rab with RHD+myxo 1 10-08

Tagged European rabbit kitten infected with myxoma virus, but that died from rabbit haemorrhagic virus disease (RHDV). Photo by David Peacock, Biosecurity South Australia.

“Canberra, we have a problem” — Sure, it’s an old problem and much less of one than it used to be back in the 1950s, but invasive rabbits are nonetheless an ecological, conservation, and financial catastrophe across Australia.

relative rabbit abundance South Australia

Semi-schematic diagram, redrawn using data from Saunders and others and extended to include the recent spread of RHDV2, showing changes in rabbit abundance in relation to the introduction of biological control agents into north-eastern South Australia. Dotted lines indicate uncertainty due to lack of continuous annual data. The broken line indicates a level of about 0.5 rabbits ha-1, below which rabbits must be held to ensure recovery of native pastures and shrubs (from B. Cooke 2018 Vet Rec doi:10.1136/vr.k2105)

Rabbits used to reach plague numbers in much of agricultural and outback Australia, but the introduction and clever manipulation of two rather effective rabbit-specific viruses and insect vectors — first, myxoma virus in 1950, European rabbit fleas in the 1960s to help spread the virus, then Spanish rabbit fleas in the 1990s to increase spread into arid areas, and then rabbit haemorrhagic disease virus (RHDV) in 1995 — have been effective in dropping rabbit abundances by an estimated 75-80% in South Australia alone since the 1950s.

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What’s in a name? The dingo’s sorry saga

30 01 2015

bad dingoThe more I delve into the science of predator management, the more I realise that the science itself takes a distant back seat to the politics. It would be naïve to think that the management of dingoes in Australia is any more politically charged than elsewhere, but once you start scratching beneath the surface, you quickly realise that there’s something rotten in Dubbo.

My latest contribution to this saga is a co-authored paper led by Dale Nimmo of Deakin University (along with Simon Watson of La Trobe and Dave Forsyth of Arthur Rylah) that came out just the other day. It was a response to a rather dismissive paper by Matt Hayward and Nicky Marlow claiming that all the accumulated evidence demonstrating that dingoes benefit native biodiversity was somehow incorrect.

Their two arguments were that: (1) dingoes don’t eradicate the main culprits of biodiversity decline in Australia (cats & foxes), so they cannot benefit native species; (2) proxy indices of relative dingo abundance are flawed and not related to actual abundance, so all the previous experiments and surveys are wrong.

Some strong accusations, for sure. Unfortunately, they hold no water at all. Read the rest of this entry »

It’s not all about cats

20 10 2014

Snake+OilIf you follow any of the environment news in Australia, you will most certainly have seen a lot about feral cats in the last few weeks. I’ve come across dozens of articles in the last week alone talking about the horrendous toll feral cats have had on Australian wildlife since European arrival. In principle, this is a good thing because finally Australians are groggily waking to the fact that our house moggies and their descendants have royally buggered our biodiversity. As a result, we have the highest mammal extinction rate of any country.

But I argue that the newfound enthusiasm for killing anything feline is being peddled mainly as a distraction from bigger environmental issues and to camouflage the complete incompetence of the current government and their all-out war on the environment.

Call me cynical, but when I read headlines like “Australia aims to end extinction of native wildlife by 2020” and Environment Minister Hunt’s recent speech that he has “… set a goal of ending the loss of mammal species by 2020“, I get more than just a little sick to the stomach.

What a preposterous load of shite. Moreover, what a blatant wool-pulling-over-the-eyes public stunt. Read the rest of this entry »

Can Australia afford the dingo fence?

18 05 2012

I wrote this last night with Euan Ritchie of Deakin University in response to some pretty shoddy journalism that misrepresented my comments (and Euan’s work). Our article appeared first in The Conversation this morning (see original article).

We feel we have to set the record straight after some of our (Bradshaw’s) comments were taken grossly out of context, or not considered at all (Ritchie’s). A bubbling kerfuffle in the media over the last week compels us to establish some facts about dingoes in Australia, and more importantly, about how we as a nation choose to manage them.

A small article in the News Ltd. Adelaide Advertiser appeared on 11 May in which one of us (Bradshaw) was quoted as advocating the removal of the dingo fence because it was not “cost effective” (sic). Despite nearly 20 minutes on the telephone explaining to the paper the complexities of feral animal management, the role of dingoes in suppressing feral predators, and the “costs” associated with biodiversity enhancement and feral control, there wasn’t a single mention of any of this background or justification.

Another News Ltd. article denouncing Ritchie’s work on the role of predators in Australian ecosystems appeared in The Weekly Times the day before, to which Ritchie responded in full.

So it’s damage control, and mainly because we want to state categorically that our opinion is ours alone, and not that of our respective universities, schools, institutes or even Biosecurity SA (which some have claimed or insinuated, falsely, that we represent). Biosecurity SA is responsible for, inter alia, the dingo fence in South Australia. Although our opinions differ on its role, we are deeply impressed, grateful and supportive of their work in defending us from biological problems. Read the rest of this entry »

Know thy threat

9 06 2011

Here’s another great guest post by Megan Evans of UQ – her previous post on resolving the environmentalist’s paradox was a real hit, so I hope you enjoy this one too.

The reasons for the decline of Australia’s unique biodiversity are many, and most are well known. Clearing of vegetation for urban and agricultural land uses, introduced species and changed fire patterns are regularly cited in State of the Environment reports, recovery plans and published studies as major threats to biodiversity. But, while these threats are widely acknowledged, little has been done to quantify them in terms of the proportion of species affected, or their spatial extent at a national, state or local scale. To understand why such information on threats may be useful, consider for instance how resources are allocated in public health care1.

Threat knowledge

Conditions such as cancer, heart disease and mental health are regarded as National Health Priority Areas in Australia, and have been given special attention when prioritising funds since the late 1980s. The burden of disease in these priority areas are quantified according to the incidence or prevalence of disease or condition, and its social and economic costs. Estimates of burden of disease and their geographic distribution (often according to local government areas) can assist in communicating broad trends in disease burden, but also in prioritising efforts to achieve the best outcomes for public health. An approach similar to that used in healthcare could help to identify priorities for biodiversity conservation – using information on the species which are impacted by key threats, the spatial distributions of species and threats, and the costs of implementing specific management actions to address these threats. Read the rest of this entry »

Student opportunities with Australian Wildlife Conservancy

8 09 2010

A colleague of mine, Dr. Matt Hayward of the Australian Wildlife Conservancy (AWC), asked me to circulate some Honours, MSc and PhD student project opportunities. I thought this would be best done by publishing the call as a blog post.

The AWC is a non-government, non-profit organisation dedicated to the conservation of Australia’s wildlife and their habitats. AWC’s south-east region has a team of 7 ecologists who work closely with the land managers to carry out AWC’s Conservation and Science Program. The Science Program includes strategic research designed to help us manage threatened species more effectively. Several of these research projects are suitable for Honours, Masters or PhD projects.

This prospectus provides an outline of the student projects that are currently on offer in the south-east region. The majority of the projects are based on one sanctuary, although some aspects of the research may be done on other AWC sanctuaries and/or government conservation areas.

AWC will partially support these projects with equipment, staff time and expertise, and accommodation. In some cases, AWC may also provide some vehicle use and office facilities onsite at The Scotia Field Research Centre. We anticipate these projects will be collaborative efforts with input from students, academics and AWC staff, with appropriate acknowledgement for all involved. These projects are offered on a first in, first approved basis and have been offered to multiple universities.

More details on the sanctuaries and AWC are available here. If you are keen do one of these projects, please contact Matt Hayward and we will then formulate a research proposal and research agreement. Eight project descriptions follow. Read the rest of this entry »