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CSIRO Submission 18/641

The impact of feral deer, pigs and goats in Australia

Senate Standing Committee on Environment and Communications

November 2018

Enquiries should be addressed to: Main Submission Author(s): Dr Grant Farrell Peter Caley, Senior Research Scientist, Data61 CSIRO M inisterial and Parliamentary Liaison and GPO Box 1700 Canberra 2601 Dr Justin Perry, Research Scientist, Land & Wat er

Table of Contents Table of Contents ...... 2 Executive Summary ...... 3 Introduction ...... 4 CSIRO response to the Terms of Reference (ToR) ...... 5 a) the current and potential occurrence of feral deer, pigs and goats across Australia ...... 5 b) the likely and potential biosecurity risks and impacts of feral deer, pigs and goats on the environment, agriculture, community safety and other values ...... 8 c) the effectiveness of current state and national laws, policies and practices in limiting spread and mitigating impacts of feral deer, pigs and goats ...... 11 d) the efficacy and welfare implications of currently available control and containment tools and methods, and the potential for new control and containment tools and methods ...... 13 e) priority research questions ...... 15 f) the benefits of developing and fully implementing national threat abatement plans for feral deer, pigs and goats...... 17 g) any other related matters ...... 17 References ...... 18

CSIRO submission 18/641 2 November 2018

Executive Summary

Deer are emerging as a potentially major wildlife management issue that are anticipated to affect much of Australia, as together Australia’s six species can colonise most Australian habitats.

The environmental impacts of deer are not well known. This is a critical information gap that may hamper the development of effective management responses and potentially hinder broader public acceptance of control actions should they be required. The limited ability of current control options to reduce deer populations in all but open environments means eradication is likely to be infeasible except, perhaps, in small and isolated locations.

Management of deer is made complex by many competing interests. Thus a national threat abatement plan for wild deer should (1) enable strategic planning, prioritisation and coordination of research and management actions among researchers, key interest groups and government agencies, (2) provide explicit performance criteria which allow researchers and responsible government agencies to measure and report on progress against measureable targets, and (3) guide and facilitate research investment.

Feral pigs are a more established, well known pest species than deer, with a considerable amount of existing knowledge relating to impacts and management options encapsulated in a National Threat Abatement Plan. They are, however, still expanding their range and new impacts are emerging.

Lived management experience indicates that traditional approaches to population control that rely on recurrent resourcing are not sustainable, and that new approaches are required. The impacts of pigs are often on highly localised assets (e.g. crops, wetlands, turtle rookeries). This suggests an asset-protection focussed approach to minimising feral pig impacts may be a more viable solution. Preventing pig access to such localised resources may also act as a form of population regulation. This approach is consistent with the strategic intent of the current Threat Abatement Plan.

CSIRO is using state-of-the-art tracking devices and trialling detection sensors to explore how feral pigs use their environment and how restricting resources might work in practice to develop automated asset- protection focussed responses. Lands of Northern Australia that are managed by Aboriginal and Torres Strait Islander communities have experienced a disproportionate impact from feral pigs, but those communities are also deriving benefits from them. Involving local groups in managing the impacts of feral pigs appears to offer a potentially more effective and sustainable approach, and CSIRO is undertaking research in this area.

Feral goats remain a serious threat to biodiversity over large tracts of Australia’s rangelands. Methods of control are well known and highly effective if implemented well. However progress in mitigating impacts has been limited and the range of feral goats is continuing to expand in places. It is not clear whether a national threat abatement plan can effectively address this, as economic and social interests in feral goat management are at odds with minimising environmental impact.

CSIRO is in the process of developing a range of tools and technologies for more efficient, effective and feasible management of the three ungulate types. We have identified research gaps that include opportunities for: • Better monitoring of species impacts and efficacy of control programs, • Socio-economic research — human geography of feral animal management, • Determining underlying resource drivers of feral animal populations, and • Spatial and temporal mapping of resources and populations.

CSIRO submission 18/641 3 November 2018

Introduction CSIRO welcomes the opportunity to provide input to the Senate Standing Committee on Environment and Communications’ inquiry into the impact of feral deer, pigs and goats in Australia.

Recent CSIRO research in relation to feral animals has focused on management and ecological impacts, particularly of feral pigs (e.g. Caley 2008; Caley and Welvaert 2018; Murray et al. 2015; see also https://www.csiro.au/en/Research/LWF/Areas/Ecosystems-biodiversity/Managing-landscapes-for- biodiversity/Feral-animals/Tracking and https://www.csiro.au/en/Research/LWF/Areas/Ecosystems- biodiversity/Managing-landscapes-for-biodiversity/Feral-animals) and ecological relationships between predation and deer (e.g. Forsyth, Caley et al. 2018a; Forsyth et al. 2018b).

CSIRO’s submission provides an overview of relevant science against the Terms of Reference for the inquiry and CSIRO would be pleased to discuss any aspect of this submission with the Committee.

CSIRO submission 18/641 4 November 2018

CSIRO response to the Terms of Reference (ToR) a) the current and potential occurrence of feral deer, pigs and goats across Australia

General considerations

Populations of herbivores colonising new ranges typically undergo dramatic growth, followed by a population crash, then partial recovery to a lower density that fluctuates based on the seasons – a phenomenon termed an ungulate ‘irruption’. The phenomenon was first described and explained by the late CSIRO scientist Graeme Caughley (Caughley 1970, 1987), and is consistently repeated when herbivores are introduced to or invade new ranges (Forsyth and Caley 2006). The relevance here is that the impact of invading populations tends to be highest in the early phases as the invading populations approach their peak, and highly palatable food resources are exhausted. As an example, Australia’s rangeland sheep population reached peak numbers near the end of the 19th century, only to crash during the Federation drought. Populations never recovered to anywhere near the peak levels, as the palatable plant species were replaced within the vegetation mix with those less palatable. It was during this period of high sheep and rabbit numbers, in conjunction with the arrival of foxes, that most of Australia’s now extinct mammal fauna were seen for the last time (Johnson 2006). Feral pig, wild deer and goat populations introduced to new ranges exhibit similar irruptive behaviour, with the time from introduction to peak density as long as several decades (Forsyth and Caley 2006). For example, peak densities of feral pigs were seen in many regions of NSW in the early 1970s (e.g. Giles 1980), whereas in East Arnhem Land peak densities didn’t occur until the late 1990s early 2000s as these populations were founded much more recently (Caley 1997). Deer are yet to reach peak densities in much of their current range (Moriarty 2004).

Deer

Current distribution

The current distribution of wild deer in south-eastern Australia is more an artefact of locations of escape and liberation than climate and habitat suitability. Fallow (Dama dama); red (Cervus elaphus); rusa (Cervus timorensis); sambar (Cervus unicolour); chital (Axis axis) and hog (Axis porcinus) deer have established wild populations in eastern Australia (Moriarty 2004). Amongst these, there is a species suitable for nearly all climates and habitats other than the arid interior (Caley et al. 2011). • Fallow deer currently have the most widespread distribution within south-eastern Australia, with established populations ranging from the SA to the NSW/QLD border (West and Saunders 2007). In Tasmania, fallow deer are already widespread, though are still expanding their range (Hall 2009). • Populations of rusa deer are thriving in a diverse range of habitats, ranging from the NSW south coast and southern suburbs of Sydney (Moriarty 2005) to the western suburbs of Brisbane (Pople et al. 2009). • Sambar deer are steadily expanding their range into southern New South Wales and the ACT (Styles 2009) from their stronghold in Victoria (Wright et al. 2009). • Red deer, which probably are least tolerant of disturbance, are widespread and expanding in south- east Queensland (Dryden 2009), parts of NSW and western Victoria (Wright et al. 2009). They are still finding their way to the temperate climates they prefer, with populations on the periphery of the Australian high country. In time, they can be expected to successfully colonise sub-alpine habitats, and utilise alpine habitats extensively during summer months. • Rusa, red and fallow deer appear to be expanding their range in Western Australia (Woolnough and Kirkpatrick 2009).

CSIRO submission 18/641 5 November 2018

• Five deer species (all bar hog deer) are present in South Australia, most notably in the south-east (Williams 2009).

Future distribution

With time, deer species will likely colonise most of south-eastern mainland Australia, particularly the pasture-forest interface. This will be a result of natural spread and deliberate releases, which past experience suggests will occur despite the best efforts of authorities, and have been estimated by Moriarty (2004) to account for 58% of herds. Points of liberation are anticipated to include lands bordering the conservation estate or the estate itself. The general observation is that wherever there are farmed deer there are often escaped deer, with deer farm escape/releases accounting for 35% of herds in Australia as of 2004 (Moriarty 2004) and 38% of recent populations in New Zealand (Fraser et al. 2000) — there appears to be no such thing as deer reliably “contained behind wire" as escapes are common (Fraser et al. 2003). Expected diversification of land use will be to their advantage, as they thrive in "melded" landscapes (e.g. Hewison et al. 2009).

In the long term, inter-specific competition, possibly to the point of exclusion, is likely to occur between deer species. For example, in the central North Island of New Zealand, the replacement of red deer in parts of their historical range by sika deer (Cervus nippon) is attributed to their competitive advantage in digesting fibrous forage (Fraser 1996). Similarly, rumination in sambar deer (considered a "tropical" species) is more efficient than in red deer (a "temperate" species), which may have evolved to enable them to break down low-quality tropical forages more effectively (Semiadi et al. 1994). The red deer population in south-east Queensland can be expected to experience considerable competition from the recently established rusa deer population, and ultimately sambar deer. Fallow deer are particularly effective at inter-specific competition (Focardi et al. 2006). The exact outcome from these competitive interactions are difficult to predict, however we expect the ultimate ranges of the various deer species may look very different to what we see currently. A warming climate may be expected to directly influence the distribution of individual deer species, but as there are species capable of surviving in nearly all climates, the overall distribution of deer per se will quite possibly be affected only slightly—they are likely to be distributed over all but the arid interior and intensively developed agricultural land (Caley et al. 2011).

Sambar and rusa deer appear particularly tolerant of human disturbance and adept at inhabiting environments with patchy refugia. For example, rusa deer are currently well established in the “leafy” western suburbs of Brisbane (Pople et al. 2009) and the Sutherland Shire south of Sydney, where they are commonly observed in people’s backyards (Hamilton-Irvine 2017), and are able to handle the regular disturbance arising from foraging in such areas (Anon 2018). Sambar deer are well established in the Yarra Valley in Melbourne. Red and fallow deer may also live close to major urban centres where small woodlots provide cover (Fraser et al. 2000).

In summary, it is anticipated that the existing wild deer species in eastern Australia will progressively colonise nearly the entire eastern seaboard, Great Dividing Range and the western slopes. History would suggest that the final distribution of deer species will be largely determined by the interactions between the deer themselves and land use.

Feral pigs

Current distribution

The feral pig (Sus scrofa) is widely considered as one of the worst invasive species throughout its introduced range (Barrios-Garcia and Ballari 2012). In Australia, after two centuries of recurrent introductions, translocations and natural dispersal, feral pigs are now among the most abundant and widespread terrestrial mammals (West 2008). Feral pigs are particularly widespread in the tropical north. Significant gaps in our spatial knowledge of species distribution and abundance continue to exist.

CSIRO submission 18/641 6 November 2018

To some extent, the current distribution of wild pigs still reflects initial release sites, and they were still expanding their range in NSW in 2004 (West and Saunders 2007) despite dry conditions in the preceding years. This is consistent with other conclusions that they expand their range only slowly (at about 2 km per year calculated by Caley (1997) and 4 km per year reported by Hone and Stone (1989)). As with their worldwide distribution (including wild boar), the distribution of wild pigs in south-eastern Australia incorporates a wide variety of habitats and climates. The wild pig is a habitat generalist—the most pertinent question is “why aren’t pigs present” in a location as opposed to why are they present. There are some hard environmental boundaries; they must have access to permanent water year round, and can’t cope with excessive (about 50cm) winter snow depth (Melis et al. 2006). Winter harshness imposes density-independent mortality on wild boar populations (Melis et al. 2006), however, there are few areas in south-eastern Australia that have such harsh winter conditions. At the opposite temperature extreme, they must have access to water and thermal refuges such as riverine woodlands in extremely hot weather, and their distribution within a landscape appears limited by temperature interacting with thermal refuges (Choquenot and Dexter 1995; Dexter 2003). Artificial water is generally available at regular intervals spread throughout pastoral lands.

Many field studies have empirically investigated local habitat use and population density in response to environmental and biotic factors (Caley 1993b; Corbett 1995; Caley 1997; Choquenot and Ruscoe 2003; Wurster et al. 2012). However, detailed observations remain confined to study sites and have rarely been integrated with spatially-explicit landscape data. Hone (1990a) consolidated five published studies to estimate the total size of the feral pig population in Australia. With a limited sample size and no spatial integration, this estimate remained enormously uncertain (95% confidence interval: 3.5 – 23.5 million pigs). Several studies have mapped distributional patterns of feral pigs at the regional or continental extent (Mitchell J 1982; Wilson et al. 1992). These efforts have typically relied on expert-derived relative estimates per coarse land parcel and have been poorly validated, limiting their usefulness for on-ground applications. Other ongoing initiatives such as the Atlas of Living Australia or FeralPigScan collate and map occurrence records across Australia from a range of sources, including historical surveys or citizen science. Unfortunately, these mapping initiatives suffer from lack of coverage both spatially and temporally. One statistical habitat model has inferred feral pig distributions from environmental predictor variables in northern Australia (Cowled and Giannini 2007; Cowled et al. 2009). However, the model markedly underestimated feral pig distributions when extrapolated beyond the original study site. This is not surprising, as the type of model used (GAM) often does not extrapolate well to novel environments (Wood 2006).

Future potential distribution

Changing land use, such as increasing areas of forestry and setting aside land to provide ecosystem services, is anticipated to have a positive effect on wild pig distribution. Interspersing refuge habitat with food resources will improve landscape complementation, thus improving pigs foraging efficiency and population growth rates (Choquenot and Ruscoe 2003). Greater connectivity of suitable habitat will likely assist wild pigs in colonising new areas. At the same time that landscape complementation makes the environment more favourable to pigs, changes in land tenure (e.g. increasing numbers of hobby farms) will make control operations over biologically meaningful areas more difficult to coordinate. Increased temperatures in the interior are expected to reduce the distribution of wild pigs in inland areas of eastern Australia where there is already strong evidence to indicate they are thermally limited, all the more so if surface water availability is also reduced. Further capping of free flowing artesian bores ("bore drains") and better management of water troughs when paddocks don't have stock may decrease the ability of pigs to persist in semi-arid areas.

CSIRO research has recently developed a spatially-explicit, resource-based modelling framework aimed at generating improved seasonal and regional-scale knowledge of feral pig distributions, and applied it to northern Australia (Froese et al. 2017), south-eastern Australia (Murray et al. 2015) and south-western

CSIRO submission 18/641 7 November 2018

Australia (Murray et al. 2017). Models were parameterized from expert knowledge, integrated important ecological factors such as variability in environmental conditions, breeding requirements and home range movements. A cursory validation in northern Australia suggested that empirical wild pig presences may have been accurately predicted (Froese et al. 2017).

Goats

Current distribution

Predation by dingoes/wild dogs and control by humans (including fencing) are by far the biggest influences on the distribution and abundance of feral goats (Forsyth et al. 2018b). Currently, feral goat populations thrive in predominantly sheep rangeland areas of all mainland states where the dingo/wild dog populations are either heavily controlled or absent. Elsewhere, in the absence of rugged terrain providing refuge, goat populations cannot persist in the presence of dingoes/wild dogs. Indeed, Parkes et al. (1996) note there are many examples where the presence of uncontrolled populations of dingoes/wild dogs has restricted the distribution of feral goats, or where the removal of dingoes has allowed feral goats to colonise. However, feral goats appear capable of coexisting with uncontrolled dingo/wild dog populations in rugged gorge country (e.g. Bayne et al. 2000). In the absence of dingoes/wild dogs, the persistence of feral goat populations is often facilitated by compliant landholder attitudes (Parkes et al. 1996), whereby a population is maintained to be harvested if desired.

Future potential distribution

Being generalist herbivores, in the absence of predation, goats are capable of colonising virtually all of Australia other than desert areas without permanent water. Hence the future distribution of feral goats will likely be largely determined by land manager (both private and public) decisions. Farming goats is currently a lucrative commercial proposition for many properties that have struggled financially in recent times. This appears to have led to an increased distribution of ‘farmed’ goats (Ellicott 2017; Griggs 2017). Conversely, the rewilding push to see dingoes returned (e.g. Newsome et al. 2015) to fulfil an apex predator role may see an increase in the distribution of dingoes that could lead to a reduction in the distribution of feral goats. The move towards cluster fencing to protect sheep enterprises may also, somewhat perversely, lead to increased dingo/wild dog distribution, as motivation to undertake wide-scale control efforts outside these fenced areas may lessen. Lastly, where dingoes/wild dogs are not present, feral goat populations will be subject to increasing scrutiny for their negative impacts on biodiversity and their ability to reduce ecosystem carbon storage (e.g. Mills et al. 2005). The most recent threat abatement plan (TAP) for feral goats (DEWAR 2008) aims to prevent unmanaged goats colonising new areas in Australia, although a review considered it was failing in this regard (DoE 2013).

b) the likely and potential biosecurity risks and impacts of feral deer, pigs and goats on the environment, agriculture, community safety and other values General considerations

Before listing the negative impacts for each species, we note that pigs, deer and goats are all considered a resource by some landowners, recreational hunters and commercial safari operators. Indeed, ABARES trade data (http://www.agriculture.gov.au/export/controlled-goods/meat/statistics) shows that Australia is the largest global exporter of goat meat because of harvesting from feral goat populations. The species considered in this submission, (and other introduced herbivores) are considered a valued food source for many Aboriginal and Torres Strait Islander groups. Within the public domain these species are also considered to have intrinsic value living in ecosystems within Australia.

CSIRO submission 18/641 8 November 2018

In terms of ranking the three ungulate types of interest, within New South Wales (where all three types have been long established), feral goats pose by far the greatest threat to threatened species (particularly plants), though feral pigs threaten more critically endangered (micro-endemic) species (see Table I in Caley et al. 2011).

Deer

There is very little, if any, published work on the biodiversity impacts of introduced deer in Australia, other than documentation that they browse species considered endangered (Moriarty 2005). A recent review by Davis et al. (2016) found that evidence of impacts in Australia was largely observational, with few studies experimentally partitioning the impacts of deer from those of sympatric native and other introduced herbivores. In contrast, Dolman and Waber (2008) document many instances of introduced deer causing major disturbance to local ecosystems where they have reached high abundance, although none of the cited instances came from Australia. Note that the six deer species in Australia are by no means equivalent. They differ in size (hog the smallest, sambar the largest) and in food preference (e.g. fallow deer are predominantly a grazer, whilst sambar deer are a browser (Van Dyck and Strahan 2008)). Any prediction that simply assumes because deer are a browsing species, their impact in Australian ecosystems will be novel (and hence possibly deleterious) needs to be considered in the light of Australia's vegetation once having been subject to browsing by at least six species of short-nosed kangaroo (Johnson 2006). This is in contrast to the impact of deer in New Zealand forest ecosystems, where the vegetation is considered relatively "naïve" to ruminant herbivory (Nugent et al. 2001). That said, it may well be that the impact of deer in Australia will be density-dependent, and that some form of control or predation will be needed to stop their densities becoming a threatening process to biodiversity. Our experience suggests that deer are an increasing threat to community safety through vehicle-deer collisions. There are few, if any, accessible analyses, though anecdotal reports are increasing (e.g. Humphries 2018). Research is currently underway in the Centre of Invasive Species solutions on the role feral deer may play and a reservoir of notifiable animal diseases.

Feral pigs

Physical impacts

Feral pigs have a direct physical impact in both natural landscapes as ecosystem engineers as well as in the cultural landscape as pests. Rooting is damaging at the ecosystem level: directly damaging the ground and vegetation (Mitchell et al. 2007) and impacting plant species richness (Hone 2002); increasing run-off, erosion and water quality (Waltham and Schaffer 2018); influencing soil chemistry and fungal and microbial life; and slowing regeneration (Barrios-Garcia and Ballari 2012). For remote and regional Aboriginal and Torres Strait Islander communities, pig rooting can affect vehicle access to their traditional lands as well as the values of culturally important wetlands and can damage important culturally important places and species (https://blogs.csiro.au/ecos/managing-feral-pigs-on-cape-york-its-not-a-numbers-game/).

Biodiversity & Ecosystem services

Pigs compete with and predate native animals, including frogs, lizards, annelids, turtles, birds and bird eggs (see DoEH 2005 and references therein; Bengsen et al. 2014). Micro-endemic (localised) species and species that form nesting aggregations are at particular risk of significant impact from pig predation (https://blogs.csiro.au/ecos/managing-feral-pigs-on-cape-york-its-not-a-numbers-game/). Pigs can also limit Aboriginal and Torres Strait Islander Peoples’ access to foods through the damage they cause to the environment as well as their predation on the same food sources such as yams, roots, tubers and turtles (e.g. Fordham et al. 2006). The precise effects of pig ecosystem engineering are not well understood and most likely differ broadly among different habitats and ecotypes (Mitchell et al. 2007; Barrios-Garcia and Ballari 2012), and bear further study, particularly in the Australian landscape which is often nutrient or water limited (Hughes 2003). Pigs can also be associated with large woody weed infestations (Lynes and

CSIRO submission 18/641 9 November 2018

Campbell 2000). Many impacts of feral pigs have only come to light in recent decades following the expansion of their range. For example, predation of aestivating Bogong moths (Agrotis infusa) in parts of the Australian Alps (Caley and Welvaert 2018).

Agricultural impacts

The agricultural impacts of feral pigs are well known (Tisdell 1982; McLeod 2004). In horticultural and agricultural land, there are both direct and indirect monetary losses due to feral pigs. Direct losses arise from pigs foraging-on and destroying- crops, predating lambs, and damaging infrastructure such as fences, bores, drainage and irrigation, and roads and airfields (Tisdell 1982). Pig control measures, such as paying hunters, can be costly for landholders. Indirectly, pig destruction might cause a shift in produce prices, with a flow-on cost increase to consumers. Farmers might switch to a crop that is less palatable to the pigs, but that also might earn less money per hectare. There are also flow-on effects of pig damage to infrastructure, such as machinery damaged on pig-rutted grounds, or slowed transport.

Disease host impacts

Pigs are a threat in terms of biosecurity, as actual or potential disease hosts. There is a recent southward- spread in swine brucellosis (Ridoutt et al. 2014) with concomitant cases of zoonotic transfer (Mor et al. 2016) acting as a caution to hunters and other people who directly or indirectly (e.g. via farm dogs) encounter pigs. Feral pigs in Australia have been found to harbour Giardia and Cryptosporidium, and are the only known vector of Balantidium coli (Hampton et al. 2006). All three of these parasites may cause problems in humans and are transmitted when pigs contaminate drinking water supplies.

Pigs are potential hosts of a range of livestock diseases of concern (Hampton et al. 2006) and there are concerns that feral pigs may play a role in spreading and complicating efforts to eradicate exotic diseases such as bovine tuberculosis, foot and mouth disease (FMD), African swine fever, classical swine fever (CSF), pseudo-rabies, and swine vesicular disease should they enter Australia, along with endemic diseases such as leptospirosis and anthrax. We caution, however, that the ability of individual feral pigs to become infected with these diseases does not necessarily equate to a significant risk at the population level of outbreaks that impinge on other animal health, and some of these fears may be unfounded. Epidemiologists have argued that viruses such as FMD and CSF may not persist in feral pig populations due to a lack of connectivity between pig populations, and the absence of a carrier state for the pathogen (Cowled et al. 2012). Also, CSIRO research (Corner et al. (1981) that predicted feral pigs in Northern Australia were effectively an end-host for bovine tuberculosis was confirmed by McInerney et al. (1995), following the successful Brucellosis and Tuberculosis Eradication Campaign (BTEC). The spread of African swine fever in a recent European outbreak has been facilitated by wild boar (Bosch et al. 2017).

Apart from regular sampling as part of the Northern Australia Quarantine Strategy (NAQS), most sampling and testing of feral pig populations for disease is opportunistic, which can make disease detection unreliable. A poor understanding of disease transmission between pigs under Australian conditions and the degree of connectedness between populations with changing seasons also limits our capacity to quantify their risks as disease vectors (Caley 1993a). One study estimated that in a worst case scenario as many as 3,077 cases of foot-and-mouth disease could occur before an FMD outbreak was detected (Hone and Pech 1990).

Goats

The impacts of goats, in the rangelands in particular, are well covered by the ‘Threat abatement plan for competition and land degradation by unmanaged goats’ (DEWAR 2008) and will not be repeated in detail here. In summary, unmanaged goats in the rangelands are a particularly prominent threat to listed plant species, ecological communities and fauna such as rock wallabies.

CSIRO submission 18/641 10 November 2018

c) the effectiveness of current state and national laws, policies and practices in limiting spread and mitigating impacts of feral deer, pigs and goats General

Much of the Commonwealth-level thinking around the principles and strategies for managing vertebrate pests remains current today. These include (after Braysher 1993):

• Consistency with ecologically sustainable development • Adopting a beneficiaries-pays approach • Maximising benefit-cost ratio • Defining the role of policy instruments • Discounting and valuing benefit • Involvement of all major interest groups and developing ownership of the problem • Managing total grazing pressure • Consideration of animal welfare

It is also important to recognise the difference between seeking to reduce the unwanted impact, as opposed to targeting the species. That is, ‘play the impact’ and not the species. Feral animal species should not be targeted on the basis of them being non-native. Success should not be measured by the head-count of animals killed, but the change in the impact of the environmental/agricultural asset in question. Hence control shouldn’t be undertaken in the absence of monitoring of the change in impact.

Given limited resources, having an asset-based focus will typically yield a better outcome than targeting the species in a widespread sense. The New Zealand experience with managing deer (which started >100 years ago) demonstrates the futility of attempting widespread population control without sufficiently cost- effective techniques, and multiple competing interests (Caughley 1983). The same issues are present in Australia for the three types of feral animal under consideration – they are already widely spread with large populations, and all have competing interests. Eradication is not technically feasible at scale, and the word ‘eradicate’ should not be used in any context other than localised areas that can be effectively considered as islands.

Given the extensive distribution of all three types of feral animal, it makes sense to take an ‘asset- protection’ based approach to managing populations of wild deer, feral pigs, and goats as opposed to targeting populations more generally. Taking an asset-focussed approach opens up a range of more targeted management options that are detailed in Section (e).

Deer

The population growth rate of deer, and especially the smaller species, is such that a high level of population removal would be required to exert any control over population size. For example, the finite rate of increase for suburban white-tailed deer (Odocoileus virginianus) from a site in the United States was 1.78 yr-1 (Nielsen et al. 1997). This would require in excess of 40% annual removal to exert control over the population (Hone 2007, Fig. 3.7, p52). Nugent and Choquenot (2004) note that in New Zealand neither commercial nor recreational hunting is likely to be a cost-effective alternative to state-funded control where very low deer densities are required to achieve conservation goals in inaccessible or difficult-to-hunt areas. History strongly suggests the chances of a state-sponsored control program achieving high levels of control over any sizeable area are slim (e.g. Caughley 1983). Controlling deer in forested areas is especially problematical, and recent New Zealand work has failed to detect any response of deer culling operations to best practice management (Ramsey et al. 2017). The propensity for individuals to translocate deer into new

CSIRO submission 18/641 11 November 2018

areas makes containment an unsustainable strategy, given the ongoing cost of eradicating new populations. History and current trends strongly suggest that preventing the spread of deer will be difficult.

The potential for dingoes/wild dogs to act as a biocontrol agent for wild deer is unclear but worthy of further study (Forsyth et al. 2018b). Based on interactions between the dingo-sized coyote (Canis latrans) and deer species in North America (e.g. Stout 1982; Berger et al. 2008) and the dhole (Cuon alpinus) in Eurasia (Andheria et al. 2007), it appears possible that dingoes/wild dogs may limit, and in some cases regulate the abundance of smaller deer species (e.g. fallow, chital, hog). Research from Victoria in which CSIRO has played a key role suggests that dingoes/wild dogs will not have any major impact on the large- bodied sambar deer (Forsyth et al. 2018a). There are anecdotal reports of dingoes slowing chital deer population spread in central Queensland. In general, the ability of predators to regulate non-migratory prey populations may depend on the presence of other limiting factors (e.g. drought, culling, and disease) that keep prey within the density range that can be regulated (Messier 1995) and the presence of alternative prey that maintains the predator population (Sinclair 1995). The effects on the ultimate distribution of deer in Australia are not certain, but predation and hunting have the ability to strongly influence herbivore foraging behaviour (Benhaiem et al. 2008), and may prevent deer from colonising areas considered marginal in the absence of predators.

Managing deer is a complex exercise including what people think about deer. For example, over 50% of landholders in Queensland with deer on their properties who responded to a mail survey expressed their desire for the deer population to stay at current levels or increase (Finch and Baxter 2007). Within the same survey only 25% of respondents thought deer caused environmental damage.

Feral pigs

Much of the detail developed by Choquenot et al. (1996) relating to the management of feral pigs remains relevant today.

While feral pigs are not widely seen as desirable, they are popular for recreational hunters including Aboriginal and Torres Strait Islander hunters so regulating pig numbers for the long term at regional levels and removing pigs entirely and for the long term at local scales has always been challenging. Australian wild pig meat has historically had good overseas markets, though demand has softened as wild boar populations have recovered strongly in Europe. Despite this, Aboriginal and Torres Strait Islander corporations are considering pig harvesting an input resource for other potential industries such fertilizer production, and the CSIRO is playing a key role in researching these initiatives (e.g. https://events.csiro.au/Events/2016/November/25/Science-with-Sushi-Seminar-Series-Justin-Perry).

In our experience, conflicts of interest are generally related to elimination (especially for pigs and goats). That feral pig and goat numbers should be maintained at manageable levels is more widely accepted and leads to the manner with which local regulations are applied. Australia is the highest global exporter of goat meat due to feral goats, which adds further complication to any plans to eliminate or heavily suppress populations. Sustainable harvesting therefore will not easily equate to minimising impact of these species in different habitats.

Goats

Much of the material in relation to managing feral goats presented in Parkes et al. (1996) remains relevant today. The Threat Abatement Plan for competition and land degradation by unmanaged goats (DEWAR 2008) contains much information. It was reviewed in 2013 (DoE 2013), with conclusions including “The 2008 threat abatement plan for competition and land degradation by unmanaged goats has not achieved the goal of minimising the impacts of feral goats. The problem of the impact of feral goats is complex and as feral goat numbers rise the problem is increasing.” The review also noted that much of the basic

CSIRO submission 18/641 12 November 2018

information required to manage feral goats was well known and published. Available techniques for feral goat management were publicised together with approved humane methods.

Effectively managing goats to mitigate environmental impacts is complicated by competing interests. There is a strong overseas market for feral goat meat. However, harvesting of goats via mustering and/or shooting for the purposes of generating a commercial return typically does not locally eradicate goats, and may not even reduce density appreciably over large areas (Pickles 1992), as only high density goat populations are economic to muster, after which the populations are typically left to recover. Furthermore, nannies and kids are often released, as part of a sustainable harvest.

Reintroducing dingoes is a highly effective (biological) control method for feral goats (e.g. Allen et al. 1996; Forsyth et al. 2018b). This clearly has the potential to cause direct conflict with the sheep industry, as dingoes and a viable sheep industry are essentially incompatible (Allen and West 2013), although it could be argued that the recent trend towards the use of dingo-proof cluster fencing around high value sheep enterprises introduces more flexibility to where dingoes can be located for conservation outcomes.

d) the efficacy and welfare implications of currently available control and containment tools and methods, and the potential for new control and containment tools and methods General considerations

The efficacy of currently available control and containment tools are often difficult to measure as management activity is rarely coupled with robust population monitoring or impact assessment (Reddiex and Forsyth 2006; Reddiex et al. 2006).

To be effective in protecting vulnerable environmental assets, control operations need to durable (see Braysher 2017 for a description of best practice vertebrate pest control). In the absence of recurrent efforts, populations of all three types of feral animal will recover following one-off intensive control programs (the one-off feral camel management program in central Australia at a cost of c. $20 million is a good example of this). To achieve durable control either means choosing control measures (e.g. exclusion fencing) that don’t require high levels of recurrent funding to remain effective, or identifying (and equipping) local stakeholders/land managers that are able and willing to undertake the control. This could be as a cost-effective add-on to their existing activities, or through a willingness to commit resources – a community stewardship model. The known, serious impacts of feral pigs (e.g. impacts on turtle rookeries) are highly localised, and highly amenable to a local stewardship approach to impact mitigation (https://blogs.csiro.au/ecos/turtles/). The current draft Threat Abatement Plan for feral pigs reflects this, and sensibly seeks to “identify and prioritise key species, ecological communities, ecosystems and locations across Australia for strategic feral pig management”.

CSIRO is in the process of developing a range of tools and technologies that can make such local management more efficient and feasible. This includes sensor systems to detect pest species, and autonomous systems to respond to detections (e.g. https://www.csiro.au/en/Research/LWF/Areas/Ecosystems-biodiversity/Managing-landscapes-for- biodiversity/Feral-animals/Tracking; https://blog.csiro.au/hot-on-the-tracks-of-feral-animals-in-the-top- end/ ). Here we focus on managing feral pigs:

Aerial control of pigs

Aerial shooting is not seen as acceptable by the public, despite scientific studies demonstrating that it is a humane approach to culling (e.g. Hampton et al. 2017). CSIRO has conducted an assessment of the efficacy of aerial shooting on the west coast of Cape York Peninsula (considered to have among the highest

CSIRO submission 18/641 13 November 2018

densities of feral pigs in Australia). Analysis suggested that aerial culling in high density areas was efficient, in that many pigs were culled in a short period, but that this method was not effective at reducing populations below about 20% of year 1. When considering less suitable habitats, feral pig populations were reduced during the survey and control period but local eradication did not occur. CSIRO research has shown that radio collared ‘Judas’ animals successfully seek out new family groups have proven effective, but require significant ongoing resources. Previous research indicates that in habitat types with few resource limitations feral pig populations can rapidly re-populate (1 – 2 years).

Pig baiting & trapping

Systematic intensive poison baiting can be effective if conducted for specific reasons. CSIRO worked with a regional land management organisation (Balkanu) and Aboriginal rangers (Aak Puul Ngangtam) on Cape York Peninsula to investigate the effectiveness of baiting on feral pig impacts on marine turtle nesting. A series of grain bait stations were installed along an important nesting beach for Olive Ridley turtles where marine turtle egg depredation by feral pigs was very high (100% depredation). Associated aerial control in previous years had no observable impact on reducing marine turtle depredation. Following systematic baiting over two years feral pig depredation decreased by >90% on the managed beach. This work pointed to a strong learned behaviour in feral pig populations and targeting of known resources. The targeted control methods were intensive and driven by community participation. Although this work was relatively time consuming and intensive it supported local employment and was operated entirely by local staff. The positive impact was very clear and has been maintained over several years. This suggests that targeted local action was far more effective at achieving the management goal than broad scale population control conducted at regional scales in this situation. A next-generation sodium nitrite based feral pig bait “HOGGONE” has been developed in Australia where it has been effectively trialled (https://www.pestsmart.org.au/wp-content/uploads/2011/11/HOGGONE faq.pdf). This toxin kills pigs in less than two hours which is much shorter than the next most effective toxin 1080 (sodium fluoroacetate) which takes 6–8 hours.

Like virtually all methods for controlling feral pigs, trapping rarely removes all individuals (Choquenot et al. 1993; Caley 1994). It has distinct disadvantages to other methods that include the need for vehicular access, a time delay to achieve population reduction due to the need to pre-feed traps, and expense (traps need to be checked daily). Advantages in include relative humaneness, and the ease of collecting diagnostic samples in the case of responding to disease outbreaks.

Pig hunting

Hunting, using dogs to help locate and corner pigs, can be highly effective in removing pigs that have evaded other means on control (Caley and Ottley 1995), and has successfully been used in eradication programs of pigs on islands (Ramsey et al. 2009; Parkes et al. 2010). It may be required in the advent of an exotic disease outbreak requiring localised eradication or very high levels of population suppression. Hunting, using dogs that are capable of catching pigs and holding pigs prior to be dispatched by a hunter, is widely practised, though we consider unlikely to be considered humane by many.

Recreational hunting of pigs using rifles is generally not effective in achieving population reductions over large scales unless the habitat is very open and without refuges (dense habitat). However, regular hunting of an area can act as an effective deterrent to stop pigs using an area. Pigs are of reasonably high intelligence and learn to avoid locations that are made dangerous (see Caley 2008). Hence there is a potential role for hunting in protecting localised high value environmental assets. This, however, requires hunters continue to hunt in areas where the return (in terms of pigs encountered) is very low, which to many is an unattractive proposition. For this form of control to be effective, there needs to be commitment (in a form of stewardship) on the part of the hunters involved.

CSIRO submission 18/641 14 November 2018

New method – large-scale ecological pig exclusion fencing

Even with intensive initial control and perpetual resourcing, it is very difficult to maintain effective long term control of feral pig populations, largely due to the density-dependence of their population recovery — a reduced population has higher per capita food availability and population growth (Hone 1990b; Caley 1993b; Choquenot et al. 1996). New approaches to population control are needed.

A role for exclusion fencing in minimising impacts of feral pigs has a long history in agriculture (Hone and Atkinson 1983) and environment (Liddle et al. 2006), however the scale has been small, and the underlying strategy has been simply to exclude the pigs from the asset. There has been less recognition of the effect of the asset on pig abundance. Caley (1993b) estimated that the presence of intensive high value resources (in this case sorghum and maize crops) increased the density of feral pigs four-fold. Ecological data suggests that large scale trapping and exclusion using strategically placed pig exclusion fencing could be a very effective long term control method for feral pigs (https://blogs.csiro.au/ecos/creating-indigenous-jobs- looking-after-country ). That is, by preventing access to the resource in question, the population of feral pigs is reduced. This is a new idea, and the method requires a detailed understanding of local resource use and limits to dispersal for trap and fence placement. Feral pig breeding success is determined by resource availability (Caley 1997; Dexter 1998; Wurster et al. 2012) and there is the potential to exert population control pressure by excluding animals from key environmental features (at large scales) that support breeding and growth.

New surveillance and autonomous response tools

CSIRO has developed innovative autonomous technology for detecting and tracking feral animals in remote Northern Australian landscapes (https://www.csiro.au/en/Research/LWF/Areas/Ecosystems- biodiversity/Managing-landscapes-for-biodiversity/Feral-animals/Tracking; https://blog.csiro.au/hot-on- the-tracks-of-feral-animals-in-the-top-end ). Researchers have also developed for ethically deterring pest vertebrate animals which has been deployed at scale to effectively deter elephants from crops in West Africa. The Vertebrate Pest Detect and Deter (VPDaD) system consists of a number of reactive sense and deter nodes, one or more gateways, a base station (server) and a higher level sentinel which is able to communicate (bi-directionally) with sense-and-deter nodes. The next iteration of the technology will use image analysis and AI to distinguish between species and send reports of presence in real time. This will be followed by the ability to interpret behaviour to enable the system to learn when animals are adapting to the deterrence and to respond.

New control tools

New control approaches that could be considered include oral contraceptives — synthetic oestrogen and progesterone have potential if they can be species specific in their delivery (e.g. bait stations), and approaches using gene-drive technologies might have potential in the future if this approach can be shown to be both acceptable and effective against rodents, the most likely first target, in sensible time frames and with safe release strategies (Prowse et al. 2017). One key advantage of a gene-drive approach is that it is not based on culling. A major disadvantage is the potential impact of such a genetic construct on native populations of wild boar (Sus spp.) in many other parts of the world, unless it can be demonstrated that there is acceptable risk.

e) priority research questions

In no particular order, we suggest the following priority research questions:

CSIRO submission 18/641 15 November 2018

Better monitoring of species impacts and efficacy of control programs.

Considerable public and private resources are expended annually on feral animal control. Despite this investment there are rarely requirements to quantify changes in the populations that are being managed or to quantify the impacts on environmental or agricultural outcomes. This lack of information means that management cannot necessarily adequately adapt or change management focus to reflect the success or failure of any particular intervention. Publically funded control operations should undertake robust assessments of the impacts of their control program. A key research gap is defining a minimum standard for monitoring (assessed through rigorous peer review) that could be applied in publically funded control programs. Monitoring different species in different habitats can be problematic (e.g. cryptic species, such as deer) there is therefore a need to trial and possibly adopt multiple techniques for monitoring and managing. As eradication is rarely feasible at a landscape scale, there is a need to define what impact is acceptable in different habitats and apply management accordingly. The ability/resilience of ecosystems to withstand the potential impacts of deer in particular requires careful investigation.

Socio-economic research — human geography

Social and cultural use of feral animals is one of the most important aspects of successful feral animal control. Work that CSIRO has conducted in partnership with Wik traditional owners has demonstrated positive values for retaining feral pigs in the landscape as part of customary practices and the local economy, to hunt for consumption or to supplement traditional food, and to share resources amongst kin and family. A demonstrated lack of impact from expensive broad scale control programs suggests that a more nuanced community driven approach to asset protection could achieve the same results with better community participation and support. This equally applies to other recreational hunting and conservation groups (e.g. Bengsen and Sparkes 2016). A research framework that recognises the inter-dependencies of ecosystem services and human wellbeing that supports the deployment of multiple methods is key to greater understanding of how policies, cultural institutions, technologies and human action can affect provision of services and vice-versa (Jax et al. 2013; Blicharska et al. 2017; Jackson et al. 2017). This is applicable to all ungulate types under consideration.

Underlying drivers of wild populations

Understanding what factors determine the distribution and abundance of feral animals is key to effective management. Feral pigs in particular often utilise concentrated, seasonally available resources, with a positive feedback loop exacerbating damage. Undertaking biometric studies on wild pig populations is required to better understand the physiological constraints to feral pig movement and resource limitations to breeding. Understanding these limits alongside environmental variables and climate will provide a detailed understanding of the key limiting factors. This level of understanding will allow scientists and land managers to work together to identify the resources that support uncontrolled feral pig populations and seek to engineer solutions to exclude the animals from these resources or create behavioural changes.

Spatial and temporal mapping of resources

Effectively managing feral animal populations, especially during an emergency situation, requires spatial information layers on habitat and abundance that are at the appropriate scale and sufficiently accurate, and can be updated new surveillance information comes to hand. Scaling our understanding of feral animal impacts from local research and expert elicitation requires spatial mapping products that are useful at the scale at which management occurs. Most importantly, feral animal distribution and resource use is not static and accurate spatial modelling, that will be useful for making land management decisions and responding to animal disease emergencies, requires tools that better reflect current seasonal conditions and land use. There is a potentially major though yet undefined role for the use of sensor technology in contributing to these spatial data layers in real time (https://www.csiro.au/en/Research/LWF/Areas/Ecosystems-biodiversity/Managing-landscapes-for- biodiversity/Feral-animals/Tracking)

CSIRO submission 18/641 16 November 2018

f) the benefits of developing and fully implementing national threat abatement plans for feral deer, pigs and goats General

Threat Abatement Plans are important tools for directing and prioritising research actions and CSIRO research on key threatening processes is directed at addressing priorities outlined in these plans. The benefits of fully implementing a national threat abatement plan include (1) enabling strategic planning, prioritisation and coordination of research and management actions among researchers, key interest groups and government agencies, (2) providing explicit performance criteria which allows researchers and responsible government agencies to measure and report on progress against measureable targets, and (3) guiding and facilitating research investment.

Feral deer

As we have described earlier, there has been little research on the impacts of feral deer on biodiversity generally, and particularly on threatened species and ecological communities, in Australia. There is no current synthesis of research needs for management of feral deer (remembering that there are six different species involved) and little knowledge on which to undertake asset-protection based management. A nationally coordinated approach to prioritising research would be a clear benefit of development of a threat abatement plan. The importance of community attitudes to managing deer cannot be overstated, and a TAP would be a very useful central repository for synthesising, acknowledging and addressing this.

Feral Pigs

We note that a review of the original Threat Abatement Plan for Feral Pigs concluded “… that many of the actions in the 2005 threat abatement plan have been completed and a new focus is required for threat abatement, focusing on the management of species and ecological communities specifically threatened by feral pigs in priority areas together with ongoing research requirements and monitoring.” This conclusion supports our view that an asset-protection based approach to management is likely to yield the best outcomes and that a threat abatement plan should focus on understanding and monitoring impacts to assets and managing feral pigs to mitigate those impacts. The challenge of using conventional control methods to achieve this has led to the CSIRO undertaking some innovative research on developing methods for managing high value, though localised environmental assets.

Feral goats

The 2008 threat abatement plan (DEWAR 2008) for management of feral goats appears not to have achieved its stated goals despite the relatively comprehensive published research available around the technical aspects of goat control and management (DoE 2013). The complex economic and social interests involved in goat management are difficult to address in a threat abatement plan directed at minimising environmental impact and therefore the benefit of developing such a plan while these issues remain unresolved is not clear.

g) any other related matters No specific input.

CSIRO submission 18/641 17 November 2018

References

Allen, BL, West, P (2013) Influence of dingoes on sheep distribution in Australia. Australian Veterinary Journal 91, 261-267. Allen, LR, Lee, J, Edwards, J (1996) Managing feral goats and their impact on Townshend Island in Shoalwater Bay Training Area. In 'Environmentally Responsible Defence.' (Eds P Crabbm, J Kesby, L Olive.) pp. 79-86. (Australian Defence Studies Centre, University of New South Wales: Sydney) Andheria, AP, Karanth, KU, Kumar, NS (2007) Diet and prey profiles of three sympatric large carnivores in Bandipur Tiger Reserve, India. Journal of Zoology 273, 169−175. Anon (2018) Deer Fact Sheet. Available at http://www.wollongong.nsw.gov.au/factsheets/Deer%20Fact%20Sheet.pdf Barrios-Garcia, MN, Ballari, SA (2012) Impact of wild boar (Sus scrofa) in its introduced and native range: a review. Biological Invasions 14, 2283-2300. Bayne, P, Harden, B, Pines, K, 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. Bengsen, AJ, Gentle, MN, Mitchell, JL, Pearson, HE, Saunders, GR (2014) Impacts and management of wild pigs Sus scrofa in Australia. Mammal Review 44, 135-147. Bengsen, AJ, Sparkes, J (2016) Can recreational hunting contribute to pest mammal control on public land in Australia? Mammal Review 4, 297-310. Benhaiem, S, Delon, M, Lourtet, B, Cargnelutti, B, Aulagnier, S, Hewison, AJM, Morellet, N, Verheyden, H (2008) Hunting increases vigilance levels in roe deer and modifies feeding site selection. Animal Behaviour 76, 611−618. Berger, KM, Gese, EM, Berger, J (2008) Indirect effects and traditional trophic cascades: A test involving wolves, coyotes, and pronghorn. Ecology 89, 818−828. Blicharska, M, Smithers, RJ, Hedblom, M, Hedenås, H, Mikusiński, G, Pedersen, E, Sandström, P, Svensson, J (2017) Shades of grey challenge practical application of the cultural ecosystem services concept. Ecosystem Services 23, 55-70. Bosch, J, Rodríguez, A, Iglesias, I, Muñoz, M, Jurado, C, Sánchez‐Vizcaíno, J, De la Torre, A (2017) Update on the risk of introduction of African swine fever by wild boar into disease‐free European Union Countries. Transboundary and emerging diseases 64, 1424-1432. Braysher, M (2017) 'Managing Australia's pest animals: a guide to strategic planning and effective management.' (CSIRO PUBLISHING: Clayton South, Melbourne) Braysher, ML (1993) 'Managing vertebrate pests: Principles and strategies.' (Australian Government Pub. Service: Canberra) Caley, P (1993a) The ecology and management of feral pigs in the 'wet-dry' tropics of the Northern Territory. Masters of Applied Science (unpublished) thesis, University of Canberra. Caley, P (1993b) Population dynamics of feral pigs (Sus scrofa) in a tropical riverine habitat complex. Wildlife Research 20, 625−636. Caley, P (1994) Factors affecting the success rate of traps for catching feral pigs in a tropical habitat. Wildlife Research 21, 287−292. Caley, P (1997) Movements, activity patterns and habitat use of feral pigs (Sus scrofa) in a tropical habitat. Wildlife Research 24, 77−87. Caley, P M Jambrecina (Ed.) (2008) 'Managing feral pig damage – creating a ‘landscape of fear’, Kakadu National Park Landscape Symposia Series 2007–2009. Symposium 5: Feral animal management.' Jabiru Community Centre, Kakadu National Park. (Supervising Scientist, Department of Sustainability, Environment, Water, Population and Communities: Darwin) Caley, P, Ottley, B (1995) The effectiveness of hunting dogs for removing feral pigs (Sus scrofa). Wildlife Research 22, 147−154.

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Caley, P, Tennant, P, Hood, G (2011) Modelling the distribution of vertebrate pests in New South Wales under climate change. Invasive Animals Cooperative Research Centre, Canberra. Available at https://www.pestsmart.org.au/pest-distribution-under-climate-change/. Caley, P, Welvaert, M (2018) Aestivation dynamics of bogong moths (Agrotis infusa) in the Australian Alps and predation by wild pigs (Sus scrofa). Pacific Conservation Biology 24, 178–182. Caughley, G (1970) Eruption of ungulate populations, with emphasis on Himalayan thar in New Zealand. Ecology 51, 53−72. Caughley, G (1983) 'The Deer Wars: The Story of Deer in New Zealand.' (Heinemann: Auckland) Caughley, G (1987) Ecological Relationships. In 'Kangaroos: Their Ecology and Management in Sheep Rangelands.' (Eds G Caughley, N Shepherd, J Short.) pp. 159-187. (Cambridge University Press: Cambridge) Choquenot, D, Dexter, N (1995) Spatial variation in food limitation: The effects of foraging constraints on the distribution and abundance of feral pigs in the rangelands. In 'Frontiers of Population Ecology.' (Eds RB Floyd, AW Sheppard, PJ De Barro.) pp. 531−546. (CSIRO Publishing: Collingwood, Melbourne) Choquenot, D, Kilgour, RJ, Lukins, BS (1993) An evaluation of feral pig trapping. Wildlife Research 20, 15−22. Choquenot, D, McIlroy, J, Korn, T (Ed. M Bomford (1996) 'Managing Vertebrate Pests: Feral Pigs.' (Bureau of Rural Sciences: Canberra) Choquenot, D, Ruscoe, WA (2003) Landscape complementation and food limitation of large herbivores: habitat-related constraints on the foraging efficiency of wild pigs. Journal of Animal Ecology 72, 14− 26. Corbett, L (1995) Does Dingo Predation or Buffalo Competition Regulate Feral Pig Populations in the Australian Wet-Dry Tropics? An Experimental Study. Wildlife Research 22, 65-74. Corner, LA, Barrett, RH, Lepper, AWD, Lewis, V, Pearson, CW (1981) A survey of mycobacteriosis of feral pigs in the Northern Territory. Australian Veterinary Journal 57, 537−542. Cowled, BD, Garner, MG, Negus, K, Ward, MP (2012) Controlling disease outbreaks in wildlife using limited culling: modelling classical swine fever incursions in wild pigs in Australia. Veterinary Research 43, 3. Cowled, BD, Giannini, F (2007) Spatial predictive modelling for feral pigs in northern Australia (2.054R). Australian Biosecurity CRC, Canberra. Cowled, BD, Giannini, F, Beckett, SD, Woolnough, A, Barry, S, Randall, L, Garner, G (2009) Feral pigs: predicting future distributions. Wildlife Research 36, 242-251. Davis, NE, Bennett, A, Forsyth, DM, Bowman, DMJS, Lefroy, EC, Wood, SW, Woolnough, AP, West, P, Hampton, JO, Johnson, CN (2016) A systematic review of the impacts and management of introduced deer (family Cervidae) in Australia. Wildlife Research 43, 515-532. DEWAR (2008) Threat abatement plan for competition and land degradation by unmanaged goats. Department of the Environment, Water, Heritage, and the Arts, Canberra. Dexter, N (1998) The influence of pasture distribution and temperature on habitat selection by feral pigs in a semi-arid environment %J Wildlife Research. 25, 547-559. Dexter, N (2003) The influence of pasture distribution, and temperature on adult body weight of feral pigs in a semi-arid environment. Wildlife Research 30, 75−79. DoE (2013) Threat abatement plan for competition and land degradation by unmanaged goats (2008): Five yearly review 2013. Commonwealth Department of the Environment, Canberra. Available at http://www.environment.gov.au/system/files/resources/2109c235-4e01-49f6-90d0- 26e6cb58ff0b/files/tap-review-unmanaged-goats.pdf. DoEH (2005) Threat abatement plan for Predation, habitat degradation, competition and disease transmission by feral pigs. Available at http://www.environment.gov.au/system/files/resources/eddfe958-49e0-4c11-a994- 68b113724b3a/files/feral-pig-tap.pdf Dolman, PM, Waber, K (2008) Ecosystem and competition impacts of introduced deer. Wildlife Research 35, 202−214.

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Dryden, G S McLeod (Ed.) (2009) 'Wild deer in SE Queensland – graziers’ pest or charismatic megafauna? , Proceedings of the national feral deer management workshop, Canberra, November 2005.' Canberra. (Invasive Animals Cooperative Research Centre: Canberra) Ellicott, J (2017) Goat industry on rise as price hits $7.50/kg high and Bourke abattoir set to open. The Land Available at https://www.theland.com.au/story/4714962/bourke-abattoir-on-way/ Finch, NA, Baxter, GS (2007) Oh deer, what can the matter be? Landholder attitudes to deer management in Queensland. Wildlife Research 34, 211−217. Focardi, S, Aragno, P, Montanaro, P, Riga, F (2006) Inter-specific competition from fallow deer Dama dama reduces habitat quality for the Italian roe deer Capreolus capreolus italicus. Ecography 29, 407− 417. Fordham, D, Georges, A, Corey, B, Brook, BW (2006) Feral pig predation threatens the local persistence of snake-necked indigenous harvest and turtles in northern Australia. Biological Conservation 133, 379−388. Forsyth, DM, Caley, P (2006) Testing the irruptive paradigm of large-herbivore dynamics. Ecology 87, 297− 303. Forsyth, DM, Caley, P, Davis, NE, Latham, ADM, Woolnough, AP, Woodford, LP, Stamation, KA, Moloney, PD, Pascoe, C (2018a) Functional responses of an apex predator and a mesopredator to an invading ungulate: Dingoes, red foxes and sambar deer in south-east Australia. Austral Ecology 43, 375-384. Forsyth, DM, Latham, DM, Davis, NE, Caley, P, Letnic, M, Moloney, PD, Woodford, LP, Woolnough, AP (2018b) Interactions between dingoes and wild ungulates: concepts, evidence and knowledge gaps. Australian Mammalogy in press. Fraser, KW (1996) Comparative rumen morphology of sympatric sika deer (Cervus nippon) and red deer (C- elaphus scoticus) in the Ahimanawa and Kaweka Ranges, central North Island, New Zealand. Oecologia 105, 160−166. Fraser, KW, Cone, JM, Whitford, EJ (2000) A revision of the established ranges and new populations of 11 introduced ungulates species in New Zealand. Journal of the Royal Society of New Zealand 30, 419− 437. Fraser, KW, Parkes, JP, Thomson, C (2003) 'Management of new deer populations in Northland and Taranaki.' (Department of Conservation: Wellington, New Zealand) Froese, JG, Smith, CS, Durr, PA, McAlpine, CA, van Klinken, RD (2017) Modelling seasonal habitat suitability for wide-ranging species: Invasive wild pigs in northern Australia. PloS one 12, e0177018. Giles, JR (1980) The ecology of the feral pig in western New South Wales. University of Sydney. Griggs, M (2017) Goats become more lucrative. The Land Available at https://www.theland.com.au/story/4436666/goats-become-more-lucrative/ Hall, G S McLeod (Ed.) (2009) 'Wild deer in Tasmania - exotic pest or valued resource?, Proceedings of the national feral deer management workshop, Canberra, November 2005.' Canberra. (Invasive Animals Cooperative Research Centre: Canberra) Hamilton-Irvine, G (2017) Couple woken to deer fighting on front lawn. theleader.com.au Available at https://www.theleader.com.au/story/4683016/couple-woken-to-deer-fighting-on-front-lawn/ Hampton, J, Spencer, PB, Elliot, AD, Thompson, RA (2006) Prevalence of zoonotic pathogens from feral pigs in major public drinking water catchments in Western Australia. Ecohealth 3, 103-108. Hampton, JO, Edwards, GP, Cowled, BD, Forsyth, DM, Hyndman, TH, Perry, AL, Miller, CJ, Adams, PJ, Collins, T (2017) Assessment of animal welfare for helicopter shooting of feral horses. Wildlife Research 44, 97-105. Hewison, AJM, Morellet, N, Verheyden, H, Daufresne, T, Angibault, J-M, Cargnelutti, B, Merlet, J, Picot, D, Rames, J-L, Joachim, J, Lourtet, B, Serrano, E, Bideau, E, Cebe, N (2009) Landscape fragmentation influences winter body mass of roe deer. Ecography 32, Hone, J (1990a) How many feral pigs in Australia? Australian Wildlife Research 17, 571-572. Hone, J (1990b) Note on seasonal changes in population density of feral pigs in three tropical habitats. Australian Wildlife Research 17, Hone, J (2002) Feral pigs in Namadgi National Park, Australia: dynamics, impacts and management. Biological Conservation 105, 231-242.

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Hone, J (2007) 'Wildlife Damage Control.' (CSIRO Publishing: Melbourne) Hone, J, Atkinson, B (1983) Evaluation of fencing to control feral pig movement. Australian Wildlife Research 10, 499-505. Hone, J, Pech, R (1990) Disease surveillance in wildlife with emphasis on detecting foot and mouth disease in feral pigs. Journal of Environmental Management 31, 173-184. Hone, J, Stone, CP (1989) A comparison and evaluation of feral pig management in two national parks. Wildlife Society Bulletin 17, 419−425. Hughes, L (2003) Climate change and Australia: Trends, projections and impacts. Austral Ecology 28, 423- 443. Humphries, G (2018) Deer causing more than 100 crashes in the Illawarra since 2005. Illawarra Mercury Available at https://www.illawarramercury.com.au/story/5594648/deer-causing-more-than-100- crashes-in-the-illawarra-since-2005/ Jackson, S, Palmer, L, McDonald, F, Bumpus, A (2017) Cultures of Carbon and the Logic of Care: The Possibilities for Carbon Enrichment and Its Cultural Signature. Annals of the American Association of Geographers 107, 867-882. Jax, K, Barton, DN, Chan, KMA, de Groot, R, Doyle, U, Eser, U, Gorg, C, Gomez-Baggethun, E, Griewald, Y, Haber, W, Haines-Young, R, Heink, U, Jahn, T, Joosten, H, Kerschbaumer, L, Korn, H, Luck, GW, Matzdorf, B, Muraca, B, Nesshover, C, Norton, B, Ott, K, Potschin, M, Rauschmayer, F, von Haaren, C, Wichmann, S (2013) Ecosystem services and ethics. Ecological Economics 93, 260-268. Johnson, CJ (2006) 'Australia's Mammal Extinctions: A 50 000-year history.' (Cambridge University Press: New York) Liddle, DL, Brook, BW, Matthews, J, Taylor, SM, Caley, P (2006) Threat and Response: A decade of decline in a regionally endangered rainforest palm affected by fire and introduced animals. Biological Conservation 132, 362−375. Lynes, B, Campbell, S (2000) Germination and viability of mesquite (Prosopis pallida) seed following ingestion and excretion by feral pigs (Sus scrofa). Tropical Grasslands 34, 125-128. McInerney, J, Small, KJ, Caley, P (1995) Prevalence of Mycobacterium bovis infection in feral pigs in the Northern Territory. Australian Veterinary Journal 72, 448−451. McLeod, R (2004) Counting the cost: impact of invasive animals in Australia. Cooperative Research Centre for the Biological Control of Pest Animals, Canberra. Melis, C, Szafranska, PA, Jedrzejewska, B, Barton, K (2006) Biogeographical variation in the population density of wild boar (Sus scrofa) in western Eurasia. Journal of Biogeography 33, 803−811. Messier, F (1995) Trophic interactions in 2 northern wolf-ungulate systems. Wildlife Research 22, 131−146. Mills, AJ, Cowling, RM, Fey, MV, Kerley, GIH, Donaldson, JS, Lechmere-Oertel, RG, Sigwela, AM, Skowno, AL, Rundel, P (2005) Effects of goat pastoralism on ecosystem carbon storage in semiarid thicket, Eastern Cape, South Africa. Austral Ecology 30, 797−804. Mitchell J (1982) Vertebrate pests of Queensland. Queensland. Stock Routes and Rural Lands Protection Board Mitchell, J, Dorney, W, Mayer, R, McIlroy, J (2007) Ecological impacts of feral pig diggings in north Queensland rainforests %J Wildlife Research. 34, 603-608. Mor, SM, Wiethoelter, AK, Lee, A, Moloney, B, James, DR, Malik, R (2016) Emergence of Brucella suis in dogs in New South Wales, Australia: clinical findings and implications for zoonotic transmission. BMC veterinary research 12, 199. Moriarty, A (2004) The liberation, distribution, abundance and management of wild deer in Australia. Wildlife Research 31, 291−299. Moriarty, A (2005) Ecology and environmental impact of Rusa deer Cervus timorensis in Royal National Park. PhD thesis, University of Western Sydney. Murray, JM, Van Klinken, R, Froese, J, Perry, J (2015) Assessing the risk of feral pigs interacting with domestic pig herds in southeastern Australia. Final report to Australian Pork Limited (APL), Project 2114/486. CSIRO Biosecurity Flagship, Brisbane.

CSIRO submission 18/641 21 November 2018

Newsome, TM, Ballard, GA, Crowther, MS, Dellinger, JA, Fleming, PJ, Glen, AS, Greenville, AC, Johnson, CN, Letnic, M, Moseby, KE (2015) Resolving the value of the dingo in ecological restoration. Restoration Ecology 23, 201-208. Nielsen, CK, Porter, WF, Underwood, HB (1997) An adaptive management approach to controlling suburban deer. Wildlife Society Bulletin 25, 470−477. Nugent, G, Choquenot, D (2004) Comparing cost-effectiveness of commercial harvesting, state-funded culling, and recreational deer hunting in New Zealand. Wildlife Society Bulletin 32, 481−492. Nugent, G, Fraser, W, Sweetapple, P (2001) Top down or bottom up? Comparing the impacts of introduced arboreal possums and ‘terrestrial’ ruminants on native forests in New Zealand Biological Conservation 99, 65−79. Parkes, J, Henzell, R, Pickles, G (1996) Managing Vertebrate Pests: Feral Goats. Australian Government Publishing Service, Canberra. Parkes, JP, Ramsey, DSL, Macdonald, N, Walker, K, McKnight, S, Cohen, BS, Morrison, SA (2010) Rapid eradication of feral pigs (Sus scrofa) from Santa Cruz Island, California. Biological Conservation 143, 634−641. Pickles, GS JE Borrecco, RE Marsh (Eds) (1992) 'Feral goat commercialisation: the beginning of the end of eradication, Proceedings of the Fifteenth Vertebrate Pest Conference.' Newport Beach, California. (University of California Davis, CA) Pople, T, Paroz, G, Wilke, A S McLeod (Ed.) (2009) 'Deer management in Queensland, Proceedings of the national feral deer management workshop, Canberra, November 2005.' Canberra. (Invasive Animals Cooperative Research Centre: Canberra) Prowse, TA, Cassey, P, Ross, JV, Pfitzner, C, Wittmann, TA, Thomas, P (2017) Dodging silver bullets: good CRISPR gene-drive design is critical for eradicating exotic vertebrates. Proc. R. Soc. B 284, 20170799. Ramsey, DSL, Forsyth, DM, Veltman, CJ, Richardson, SJ, Allen, RB, Allen, WJ, Barker, RJ, Bellingham, PJ, Jacobson, CL, Nicol, SJ, Robertson, AW, Todd, CR (2017) A management experiment reveals the difficulty of altering seedling growth and palatable plant biomass by culling invasive deer. Wildlife Research 44, 623-636. Ramsey, DSL, Parkes, J, Morrison, SA (2009) Quantifying eradication success: the removal of feral pigs from Santa Cruz Island, California. Conservation Biology 23, 449−459. Reddiex, B, Forsyth, DM (2006) Control of pest mammals for biodiversity protection in Australia. II. Reliability of knowledge. Wildlife Research 33, 711-717. Reddiex, B, Forsyth, DM, McDonald-Madden, E, Einoder, LD, Griffioen, PA, Chick, RR, Robley, AJ (2006) Control of pest mammals for biodiversity protection in Australia. I. Patterns of control and monitoring. Wildlife Research 33, 691-709. Ridoutt, C, Lee, A, Moloney, B, Massey, P, Charman, N, Jordan, D (2014) Detection of brucellosis and leptospirosis in feral pigs in New South Wales. Australian Veterinary Journal 92, 343-347. Semiadi, G, Barry, TN, Stafford, KJ, Muir, PD, Reid, CSW (1994) Comparison of digestive and chewing efficiency and time spent eating and ruminating in sambar deer (Cervus unicolor) and red deer (Cervus elaphus) Journal of Agricultural Science 123, 89−97. Sinclair, ARE (1995) Population limitation of resident herbivores. In 'Serengeti II. Dynamics, Management, and Conservation of an Ecosystem.' (Eds ARE Sinclair, P Arcese.) pp. 194−219. (University of Chicago Press: Chicago) Stout, GG (1982) Effects of coyote reduction on white-tailed deer productivity on Fort Sill, Oklahoma. Wildlife Society Bulletin 10, 329−332. Styles, K S McLeod (Ed.) (2009) 'Feral deer situation in the ACT, Proceedings of the national feral deer management workshop, Canberra, November 2005.' Canberra. (Invasive Animals Cooperative Research Centre: Canberra) Tisdell, CA (1982) 'Wild Pigs: Environmental Pest or Economic Resource?' (Pergamon Press: Sydney) Van Dyck, S, Strahan, R, 2008. The complete book of Australian mammals. Reed Books, Sydney. Waltham, NJ, Schaffer, JR (2018) Thermal and asphyxia exposure risk to freshwater fish in feral-pig- damaged tropical wetlands. Journal of Fish Biology 93, 723-728.

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West, P, Saunders, G (2007) Pest Animal Survey: A review of the distribution, impacts and control of invasive animals throughout NSW and the ACT. NSW Department of Primary Industries, Orange. Williams, M S McLeod (Ed.) (2009) 'Wild deer in South Australia: position paper for National Deer Workshop, Proceedings of the national feral deer management workshop, Canberra, November 2005.' Canberra. (Invasive Animals Cooperative Research Centre: Canberra) Wilson, G, McNee, A, Platts, P (1992) 'Wild animal resources: their use by aboriginal communities.' (Australian Government Publishing Service: Canberra) Wood, SN (Eds BP Carlin, C Chatfield, M Tanner, J Zidek (2006) 'Generalized Additive Models: An Introduction with R.' (Chapman & Hall/CRC: Boca Raton) Woolnough, AP, Kirkpatrick, WE S McLeod (Ed.) (2009) 'Wild deer in Western Australia: A review of the current issues Proceedings of the national feral deer management workshop, Canberra, November 2005.' Canberra. (Invasive Animals Cooperative Research Centre: Canberra) Wright, J, Varcoe, T, Toop, S S McLeod (Ed.) (2009) 'Management of deer in Victoria, Proceedings of the national feral deer management workshop, Canberra, November 2005.' Canberra. (Invasive Animals Cooperative Research Centre: Canberra) Wurster, CM, Robertson, J, Westcott, DA, Dryden, B, Zazzo, A, Bird, MI (2012) Utilization of sugarcane habitat by feral pig (Sus scrofa) in northern tropical Queensland: evidence from the stable isotope composition of hair. PLoS ONE 7, e43538.

CSIRO submission 18/641 23 November 2018