CAN RECREATIONAL HUNTING CONTROL PESTS on PUBLIC LANDS? Andrew Bengsen, Jessica Sparkes, Steven Mcleod Vertebrate Pest Research

CAN RECREATIONAL HUNTING CONTROL PESTS ON PUBLIC LANDS?

Andrew Bengsen, Jessica Sparkes, Steven McLeod Vertebrate Pest Research Unit, New South Wales Department of Primary Industries, 1447 Forest Rd, Orange NSW 2800, Australia

ABSTRACT

Public lands in Australia are increasingly being made available to recreational hunters to take introduced mammals such as wild pigs, goats, deer and canids. These species can cause substantial damage to environmental or agricultural assets, and it has often been argued that recreational hunting contributes to the amelioration of these impacts by reducing pest population densities. This position has been vigorously disputed by some parties. However, there is little locally- relevant evidence to support either side of the debate, and hence little evidence on which to base useful policy. Here, we discuss recreational hunting of introduced animals on public lands in Australia. We then present hypotheses that can be evaluated to determine whether hunting activities are contributing to pest control objectives. Finally, we hypothesize about when and where recreational hunting might be most useful. In doing so, we highlight opportunities to improve returns on public investment in recreational hunting and outline a path to resolve important aspects of the ongoing debate over the role of recreational hunting in the management of introduced species on public lands.

KEYWORDS

Amateur hunting, invasive species, pest management, sport hunting, State Forest

INTRODUCTION

Wildlife and natural resource management agencies in many parts of the world allow recreational hunting on public lands in the hope that hunters can help to reduce the damage caused by pest or over-abundant mammal populations. However, the value of hunting as a population control tool is often assumed, rather than demonstrated, and recent studies indicate that hunting alone is failing to impede the growth and expansion of some important problem animal populations (e.g. Brown et al. 2000, Massei et al. 2015).

The term “recreational hunting” encompasses many types of hunting practiced by a diverse range of hunters with different motives and objectives. Here, we define recreational hunting as any activity that involves seeking a wild animal with the intention of killing it, where the primary motivation is the attainment of positive mental states such as pleasure or satisfaction. This includes activities such as trophy hunting and non-subsistence hunting for meat, but excludes activities that are specifically organised to reduce pest animal damage. We make no claims about the ethical or philosophical validity of recreational hunting. Rather, we recognise that hunting is currently viewed as a legitimate use of public land by state governments

Unlike Europe and North America, recreational hunting has not generally been considered an important tool for managing wild animal populations on public land in Australia. However, several states now allow recreational hunting on some public lands. Target species are largely restricted to introduced mammals such as wild pigs (Sus scrofa), goats (Capra hircus), deer (Axis axis, A. porcinus, Cervus elaphus, Dama dama, Rusa timorensis, R. unicolor), leporids (Oryctolagus cuniculus, Lepus europaeus), canids (Canis familiaris, Vulpes vulpes) and feral cats (Felis catus). Many of these species are regarded as important pests to biodiversity conservation and agricultural production in Australia, and several are subject to active control programs.

Management agencies and pro-hunting groups have often argued that recreational hunting is a cost-effective means of effectively controlling pest animals (e.g. Bauer and English 2011). Lobby groups continue to promote this argument to gain greater access to public land. However, the effects of recreational hunting on pest animal populations and the damage they cause have never been comprehensively evaluated in Australia. Furthermore, there is strong opposition in some parts of the community, including many wildlife managers and researchers, to recreational hunting on public land (e.g. Booth and Low 2009). The absence of locally-relevant data precludes any rational conclusion to the debate. Consequently, recreational hunting and public land management decisions must be made and implemented in a politically volatile environment, without access to reliable knowledge.

Here, we discuss recreational hunting on public lands in Australia and propose a series of hypotheses that could be evaluated to better understand the role of recreational hunting as a pest control tool. We then suggest situations in which hunting is likely to be most useful for controlling pest animal populations and the damage that they cause. Our aim is to nominate hypotheses for future research to improve the value of recreational hunting as a pest control tool and increase benefits for public land managers, hunters and the broader community.

RECREATIONAL HUNTING IN CONTEMPORARY AUSTRALIA

Hunting has been a popular pastime in Australia since European settlement. The most recent reliable estimates suggest that about 0.9 to 1.5% of the Australian population hunt wild mammals or birds (Finch et al. 2014). In contrast to many other countries, the number of active hunters in Australia appears to be increasing (Franklin 1996, Bengsen and Sparkes 2016), although absolute numbers remain relatively low when standardized by unit area (https://www.researchgate.net/ publication/305655680_Can_recreational_hunting_control_pests_on_public_lands).

Recreational hunters are motivated by a wide range of aims and practice a diversity of hunting styles (Finch et al. 2014, Sparkes et al. 2016). When asked whether their hunting activities were at least partially motivated by a desire to control pest animals, many hunters replied that they were, suggesting a widespread desire to reduce pest animal impacts (Finch et al. 2014, Sparkes et al. 2016). However, Australian hunters

______This is the authors’ version of a paper presented at the 2016 Conservation Through Sustainable Use of Wildlife Conference The definitive version will be available in the conference proceedings and firearms owners are often careful to use language that presents their pursuits as benign, pro-social pastimes when communicating with people outside their immediate community (MacCarthy 2011), and most respondents also reported hunting for other purposes (Finch et al. 2014, Sparkes et al. 2016).

Regulation of hunting activities on public land is predominantly the responsibility of individual states, with access requirements varying among jurisdictions. In most cases, hunters can choose where, when and what they want to hunt from a range of scheduled public lands and species (e.g. http://www.dpi.nsw.gov.au/hunting/where- can-i-hunt). There is little strategic direction of recreational hunting activity, with the exception of restrictions placed on the harvest of some deer in order to maintain or improve the hunting resource (e.g. Hall and Gill 2005).

Recreational hunters also contribute to strategic pest management operations on some conservation reserves. However, these operations are highly structured and coordinated to support broader pest management programs (e.g. Natural Resources Commission 2016). While volunteer shooters participating in these operations do have recreational aims, the ultimate purpose of the programs is to achieve management objectives. Therefore, these programs do not constitute strictly recreational hunting.

THE VALUE OF HUNTING AS A PEST CONTROL TOOL

Most attempts to describe the value of recreational hunting in Australia have focused on estimating outputs, such as numbers of animals taken by hunters, assuming that these translate into valuable outcomes such as reduced environmental damage (e.g. Game Council of New South Wales 2013). This approach has been criticised as inadequate, misleading and contrary to good management (e.g. Booth and Low 2009).

A more useful evaluation would estimate the contribution that hunting makes to achieving rational a priori objectives. Ideally, objectives would be clearly framed in terms of damage mitigation and would be developed collaboratively by public land managers, neighbours and hunters (following Braysher et al. 2012). In reality, these ideals are often difficult to reach because of practical, environmental, social and economic constraints (Bengsen et al. 2014). Furthermore, as most species hunted on public lands in Australia are introduced and have no conservation value (except as game), there may be little incentive to invest in long-term manipulative studies of the effects of hunting on population dynamics.

Despite these limitations, it should be possible to obtain useful information from observational data. The level of support for hypotheses in which hunting contributes to pest management objectives can be evaluated using relationships between hunting offtake and pest population and damage dynamics (Table 1). Importantly, hunting need not halt or reverse the growth or spread of damage or populations; a decline in growth or spread, relative to what would be expected in the absence of hunting, should be sufficient to demonstrate a useful outcome.

______This is the authors’ version of a paper presented at the 2016 Conservation Through Sustainable Use of Wildlife Conference The definitive version will be available in the conference proceedings Table 1. Expected relationships between hunting offtake and pest population or damage dynamics under scenarios in which hunting reduces the growth or spread of pest animal populations or the damage they cause

Population dynamics Damage

Population growth rate scales Rate at which damage increases negatively with hunting offtake scales negatively with hunting offtake

Survival scales negatively with Growth hunting offtake, and is not offset by positively-scaled recruitment

Ratio of sites where target species Ratio of newly-damaged sites to has become extinct to newly- recovered sites scales negatively with colonised sites scales negatively with

Spread hunting offtake hunting offtake

WHERE AND WHEN HUNTING COULD BE MOST USEFUL

The ability of recreational hunting to contribute to pest animal population or damage reduction will depend on many interacting factors. These include the pest species targeted; the geography and environment of the target area; individual hunters and hunter populations and management institutions (Figure 1). Examples are discussed at length in Bengsen and Sparkes (2016). A handful of studies have examined some of these factors:

• Two studies that assessed the efficacy of hunting wild pigs with dogs concluded that the practice had limited value on its own, but could make a useful contribution to integrated management programs (McIlroy and Saillard 1989, Caley and Ottley 1995).

• Surveys have suggested that some hunters travel substantial distances to hunt (Tisdell 1982, Finch et al. 2014, Sparkes et al. 2016), but none have demonstrated a relationship between the remoteness of pest populations and the hunting pressure they receive.

Beyond these examples, there is almost no reliable information to evaluate the influence of these factors on hunting outputs or outcomes in Australia.

______This is the authors’ version of a paper presented at the 2016 Conservation Through Sustainable Use of Wildlife Conference The definitive version will be available in the conference proceedings The Pest Geography & Environment Damage type & density relationship Reserve size and shape Behavioural response to harassment Proximity to hunter populations Harvest rate: Refugia: • Value to hunters • Topography • Detectability & susceptibility • Vegetation types Population recovery: • Track pervasiveness • Population density • Reproductive capacity • Mobility Ability of recreational hunting to reduce pest densities & damage

Hunters Institutions Timing of hunting pressure Constraints on hunter activity & access Number of hunters Ability to direct hunting pressure: Hunter efficacy: • Can detect where & when it’s useful • Skill level • Can manipulate hunting pressure • Functional response to declining prey • Prey selectivity

Figure 1. Interacting factors that could be expected to influence the contribution of recreational hunting to pest animal management objectives.

In the absence of local data, we can only suggest testable hypotheses based on hunting studies from regions outside Australia; general knowledge of local pest species, populations and environments; and ecological or behavioural theory. Several hypotheses have been proposed which, if evaluated locally, could provide information to enhance the value of hunting as a pest control tool on public land:

• Populations characterised by high spatial or temporal overlap with hunters will experience greater hunting mortality than those with little overlap, all other relevant traits being equal (Bengsen and Sparkes 2016);

• The additive effect of hunting mortality will be greater when population densities are well below environmental carrying capacity than when populations are close to carrying capacity (Bengsen and Sparkes 2016);

• Populations that show consistent avoidance of hunting disturbance could be deterred from high value resources using spatially-predictable and temporally- unpredictable hunting pressure (Caley 2008, Cromsigt et al. 2013);

• Laissez-faire hunting systems, in which hunters are largely free to choose the location, time and subject of their hunt, will be more capable of reducing pest damage or density in state forests and other reserves characterised by high track density than in less accessible sites (Bengsen and Sparkes 2016); and

• Hunters who self-identify as “vermin hunters”, or those whose primary motivation is to reduce pest animal damage or density, will have a greater per capita impact on pest animal populations than those motivated primarily by consumptive objectives (Ward et al. 2008).

To these we add:

• Pest populations in small reserves or those close to large hunter populations will experience greater hunting mortality than populations in large or remote reserves; and

• Pest populations within reserves adjoining properties that conduct regular, effective pest control will experience less compensatory immigration and more enduring suppression from hunting than those in reserves surrounded by properties that conduct no effective pest control.

A complement to the second point above, is that intensive hunting activity on public reserves could also help reduce pest density on neighbouring properties (e.g. Dexter and McLeod 2015).

Some of these hypotheses could be evaluated under current recreational hunting arrangements. However, a more strategic approach to recreational hunting management would allow for more powerful studies than are currently possible and would provide a means for management agencies to respond to new information. Critical elements of such an approach would include:

• Collection of more detailed data relating to hunting activity, pest populations and pest damage than currently occurs;

• A transparent, rational framework for making inferences from data and incorporating new information into management strategy and tactics;

• Establishment of useful, achievable and socially-acceptable management objectives;

• Integration of hunting into broader pest management strategies and operations; and

• The capacity for management agencies to direct hunting pressure to situations where it is most likely to be useful.

CONCLUSION

Recreational hunting has been recognised as a legitimate use of some public lands in some Australian states, and there is increasing pressure to widen the types and extent of land available to hunters. However, existing hunting effort has rarely been effectively harnessed to achieve objectives relating to community values such as biodiversity conservation, agricultural protection and public health and safety.

______This is the authors’ version of a paper presented at the 2016 Conservation Through Sustainable Use of Wildlife Conference The definitive version will be available in the conference proceedings Moreover, there is substantial resistance to the use of public land for hunting from some parts of the community, and great skepticism about claims from hunting lobbyists and others that hunting is an effective means for reducing pest animal impacts for the benefit of the broader community.

Most of the claims made by pro- and anti-hunting campaigners remain hypothetical and unsubstantiated. Based on hypotheses emerging from an evaluation of factors likely to affect the ability of recreational hunting to advance pest management objectives, we expect that there are some situations in which hunting can make a useful contribution. However, these benefits cannot be evaluated or realised under current management regimes if useful objectives have not been determined and management agencies make little attempt to monitor or guide meaningful inputs, outputs or outcomes.

Good management of recreational hunting and pest animal populations and impacts is only possible if management agencies take a more active and strategic role. Furthermore, transparency and credibility are important foundations for the ongoing maintenance of recreational hunters’ social license to operate on public land. We therefore urge management agencies to take a more strategic approach to recreational hunting which will enhance the benefits of public investment for public land managers, hunters and the broader community.

ACKNOWLEDGEMENTS

This work was supported by the New South Wales Department of Primary Industries’ Game Licensing Unit and the Invasive Animals Cooperative Research Centre.

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