Pest Animal Control Research Articles

Scientific Assessment of the Welfare of Trapped Mammals-Key Considerations for the Use of the Sharp and Saunders Humaneness Assessment Model.

Simple SummaryThe use of traps is key to the success of many wildlife management programs but the species trapped, type of trap used and its application will influence the impacts it has on animal welfare. Scientific assessment of the impacts of trapping on mammal welfare is necessary to justify the use of traps, aid trap selection, improve trap performance and develop international standards. The Sharp and Saunders humaneness assessment model was developed for the purpose of assessing the relative humaneness of a range of pest animal control methods and has been used to assess the welfare impacts of trapping on various mammal species. The model is based on the established Five Domains model, the structure of which represents the understanding that an animal’s welfare state arises due to the sum of its mental experiences which may include pain, breathlessness, thirst or fear, among many others. Here we make key recommendations for those wishing to apply the Sharp and Saunders model to scientifically assess the welfare impacts of traps. Consideration of these points will help optimize the value of information produced using the model to support ethical wildlife management practice and policy and retain social acceptance of management programs that involve trapping.Scientific assessment of the impacts of trapping on mammal welfare is necessary to inform cost-benefit analyses of using traps in wildlife management, improve trap performance and trapping processes and develop international trap standards. The Sharp and Saunders humaneness assessment model was developed specifically for assessing welfare impacts in vertebrate wildlife management and has been used to assess the impacts of trapping various mammals. It is a specific version of the more general Five Domains model for welfare assessment which is based on the understanding that welfare state reflects the sum of the animal’s mental experiences. Our experience of applying the Sharp and Saunders model allows us to make key recommendations for those wishing to use it. First, the exact parameters of the trapping scenario to be assessed must be decided. Second, assessments should be based on published data, as well as integrating both scientific and practitioner expertise to provide rigorous and relevant outcomes. Third, conclusions about welfare impacts should be based on the appropriate indicators. As far as is possible, mental experiences should be inferred using animal-based indicators, and some representation should be provided of the scorers’ confidence in the data on which assessment is based. Careful consideration of these points will help optimize the value of information produced using the model for wildlife management decision-making.

Reproductive science and the future of the planet.

Reproductive sciences have made major contributions to human health, livestock production and environmental management in the past and will continue to do so in future. In collaboration with other disciplines, reproductive scientists can provide scientifically valid information that will allow the rational development of policies on topics such as declining fertility in men and women, livestock breeding efficiencies, climate change, pest animal control, wildlife management and environmental influences. It is imperative that the reproductive sciences are recognised by the community and policy makers as important contributors to future health and welfare of animals, humans and the planet if these potential benefits are to be captured and utilised. Reproductive Health Australia (RHA) was launched recently to advocate for reproductive biology as a national health, economic and social priority. This short review provides a snapshot of why it is imperative that reproductive science receives the recognition that is due to it and provides examples of how it can contribute to the future of the planet.

Engaging absentee landholders in ecosystem service delivery in south-eastern Australia

As absentee landownership continues to increase in many regions of Oceania and the world, there is a growing need to better understand the behaviours and values of this landholder group. The increase in absentee landholdership can impact the provision of ecosystem services, as well as alter the rural socio-cultural fabric; the values, beliefs, knowledge types and social connections amongst landholders in rural communities. Consequently, this presents challenges to natural resource management (NRM) practitioners seeking to implement better resource management strategies across property boundaries. This case study research on the Central Tablelands of New South Wales, Australia, aims to better understand the characteristics of absentee landholders, including their motivations for holding land, their existing levels of knowledge concerning land management practices, and their views and preferences for cross-property collaborations and, in turn, explore the role they could have in the delivery of ecosystem services.Our results show that recreation and amenity relating to private cultural services are the main drivers of land acquisition and motivation for land use by absentee landholders in the region. Cross-property collaborations that absentee landholders are most interested in are related to the maintenance of supporting and regulating services, particularly through weed management and pest animal control. An important implication of these findings is that the facilitation of cross-property collaboration, by accommodating for the growing heterogeneity in values and beliefs, can become a mechanism for enhancing the delivery of public-benefit ecosystem services from absentee-held land.

Total grazing pressure - a defining concept for extensive pastoral systems in the southern rangelands of Australia

In Australia, particularly in the southern rangelands, large populations of native and feral herbivores (including kangaroos, goats, rabbits, pigs, donkeys and camels, depending on the location) co-exist with domestic livestock. In recent decades the concept of ‘total grazing pressure’ has been developed, and widely accepted, to denote the total forage demand of all vertebrate herbivores relative to the forage supply. This concept provides a framework within which both domestic and non-domestic species can be managed to allow commercially viable livestock production, landscape maintenance or restoration and species conservation. The concept should have relevance wherever pest animal control programs, biodiversity conservation, or commercialisation of wildlife are conducted in conjunction with extensive livestock production. The rationale for the compilation of the Special Issue is outlined.

Can recreational hunting contribute to pest mammal control on public land in Australia?

Abstract Natural resource management agencies in many countries take advantage of recreational hunting to manage the impacts or abundance of mammal populations that damage biodiversity or environmental, economic, or social values. In Australia, public lands are increasingly being made available for recreational hunters to pursue introduced mammals that can cause substantial damage to important resources. There is fervent debate over the role that recreational hunting might play in controlling introduced mammals in Australia, and scant evidence to build management strategies upon. In this review, we combine information from Australia and elsewhere in a systematic examination of the potential for recreational hunting to contribute to the control of introduced mammals on public lands in Australia. We examine the traits of introduced mammal species and populations, geographical settings, hunters, and management agencies to propose situations where hunting might be most useful, and suggest how current practice could be improved. We find there is insufficient evidence to support or disprove arguments that contemporary recreational hunting programs are effective at controlling introduced mammal populations on public lands. Moreover, current hunting management programs offer little potential for clarifying the situation or optimizing the value of recreational hunting as a pest animal control tool. To resolve this problem, we outline a framework of competing models and diagnostic criteria for assessing the effects of recreational hunting on introduced mammal populations. We contend that hunting will continue to be an under‐utilized and over‐politicized resource until management strategy is informed by transparent monitoring based on rational strategic objectives that provide mutual benefits to hunters and public resource managers.

Thirty years of vegetation dynamics in response to a fluctuating rabbit population on sub‐Antarctic Macquarie Island

SummaryAustralia's sub‐Antarctic Macquarie Island is presently undergoing one of the most ambitious vertebrate pest eradication programmes ever undertaken. The anticipated success of this programme will release the island's tundra‐like vegetation from well over a century of grazing and disturbance from House Mouse (Mus musculus), Ship Rat (Rattus rattus) and most significantly European Rabbit (Oryctolagus cuniculus). This study describes results from 30 years of vegetation quadrat monitoring (prior to the most recent and comprehensive pest eradication programme) when lower level pest animal control programmes were underway. Plant species were assigned to one of five distinct functional plant groups: Indigenous short‐lived perennials, Introduced short‐lived perennials, Indigenous perennials rarely grazed by rabbits, Indigenous perennials occasionally grazed by rabbits and Indigenous long‐lived perennials heavily grazed by rabbits, with one species, Agrostis magellanica, analysed as a sixth monospecific group. Results from monthly rabbit counts were used to compare changes in abundance of these six groups under different rabbit populations. It was found that there were three distinct phases of rabbit activity during the study period, indicated by (i) an initial very high count year in 1980–1981, followed by (ii) 20 years of low counts ending in 2001–2002 after which (iii) counts rose to medium/high until the commencement of the eradication programme in 2010–2011. Vegetation composition and progression were distinct for these three rabbit count phases. The first four of the plant functional groups decreased under lower count periods and increased in cover under higher rabbit count periods. Agrostis magellanica appears to respond primarily to interspecies competition and is disadvantaged under extended periods of low rabbit numbers. Indigenous long‐lived perennials heavily grazed by rabbits, which includes the large tussocks and megaherbs, is inversely related to rabbit numbers. During the study period, there has also been an overall decline in plant species richness with average species count per quadrat falling by between 0.6 and 2.7 taxa. This study attempts to address the observed vegetation change from this long‐term monitoring, to discuss other potential contributing factors and to use the results to predict likely future vegetation changes after eradication of vertebrate pests.

Camera trap surveys to evaluate pest animal control operations

SummaryMany camera trap surveys aiming to detect the effects of management actions on pest animal populations are not as useful as they could be, because they do not produce informative results. We used mixed effects models, signed ranks tests and occupancy models to examine changes in the activity and occurrence of European red fox (Vulpes vulpes L.) in areas subjected to repeated fox management operations. In agricultural land, mixed effects models identified a decline in fox activity after baiting in 1 year, but not the next. Occupancy models revealed a decrease in fox occurrence in a National Park following control operations. These methods, combined with appropriate survey designs, could greatly enhance the value of many pest animal surveys conducted by management agencies.

PestSmart: An Information Toolkit for Practical Pest Animal Control

The Invasive Animals Cooperative Research Centre (IACRC) has developed an end-user centred information toolkit based on developing and implementing best-practice regional and local management strategies for pest animals. The PestSmart Toolkit has consolidated the latest knowledge on strategic planning and management of major Australian agricultural and environmental pest animal species, combined with product use manuals, case-studies, fact-sheets, guidelines and extension materials including videos and social networking. Much of this has been derived from the IACRC’s 7-year (2005-2012) research and development program, but the Toolkit also adopts prior best practise techniques and knowledge where appropriate. All PestSmart Toolkit products and publications are freely available online at www.feral.org.au/pestsmart/. A great deal of information is already live and more is on the way. Users can browse the information based on pest species of interest, type of information required (e.g., policy and legislation, management, maps, images), or information relevant to different groups of people (land managers, regional/natural resource managers, policy makers). The PestSmart Toolkit formed the basis of a nationwide PestSmart Roadshow, conducted in all state and mainland territories of Australia between January and June 2012. Roadshow events have directly demonstrated the PestSmart Toolkit, along with the use and benefits of the new and soon to be registered pest animal control products and techniques available to land managers. The overall process, which combined the establishment of the PestSmart website, 60+ factsheets and case studies, Facebook and Twitter accounts, YouTube channel, 20-stop national PestSmart Roadshow day-long events, and promotional material, has been incredibly well received and has significantly changed the face of pest animal management in Australia. This has been indicated by participant feedback, website usage, and new product sales. The PestSmart approach is recommended for other states or countries interested in reinvigorating the overall public morale and participation in pest animal control.

Managing rock outcrops to improve biodiversity conservation in Australian agricultural landscapes

Summary Rocky outcrops are prominent geological features in agricultural landscapes worldwide. Reptiles are a major component of these habitats and some species are restricted to, and more abundant on, rocky outcrops than in remnant vegetation. Rock outcrops are important to reptiles because they provide resources that are often limited in the surrounding landscape (e.g. micro‐gradients in climatic conditions, basking‐ and retreat‐sites). However, there is a knowledge gap in the literature addressing the conservation value of small, rocky outcrops. Management may be necessary to reverse habitat degradation in these systems. We identify four key areas of management that need to be addressed to improve outcrop habitat values and enhance biodiversity conservation in agricultural landscapes. Specific actions involve: (i) protecting outcrops from processes that cause damage to rock microhabitat, (ii) monitoring and managing changes in vegetation structure to maintain thermally suitable environments, (iii) applying integrated pest animal control and (iv) improving matrix management to enhance inselberg function and landscape connectivity. Further research is required to evaluate the efficacy of different management regimes on outcrop biota. We hope this paper will provide the stimulus for land managers to incorporate rocky outcrops in future biodiversity conservation programmes.

Advancing Vertebrate Pest Control on a Global Scale

Author(s): Peacock, Anthony J. | Abstract: Vertebrate pest animal control and research is a relatively small area of activity within the agricultural and environmental fields. However, it is critical for agricultural productivity and biodiversity. There is much to be gained by having vertebrate pest controllers and researchers collaborating worldwide. The critical mass achieved through collaboration will result in faster registration of new products, better implementation of new methods, and increased skills within vertebrate pest units. The plain fact is that vertebrate pest control involves the killing of animals, sometimes those with iconic status. Having the public, or even other scientists, recognize the need for animal control can be complicated because of people’s natural concern for the welfare of animals. Those involved in the sector must become better advocates for the agricultural and biodiversity benefits of animal control. Although it is very uncomfortable for many scientists, they must face up to community dialogue in all its modern forms, and not simply rely on scientific reports and published papers speaking for themselves.

Assessing the humaneness of pest animal control methods

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Control of pest mammals for biodiversity protection in Australia. II. Reliability of knowledge

Foxes, wild dogs, feral cats, rabbits, feral pigs, and feral goats are believed to have deleterious impacts on native biodiversity in Australia. However, although considerable resources have been expended controlling these six pest species, there are few reliable estimates of the effects of pest control on native biodiversity. We first show why reliable knowledge of the effects of pest animal control operations can be gained only by adopting proper experimental designs (i.e. treatment and non-treatment areas, replication, and random assignment of treatment and non-treatment areas) and monitoring of both the pest and biodiversity. We then review the design of 1915 pest control actions conducted with the aim of protecting native biodiversity in Australia during 1990–2003. Most (67.5%) pest control actions consisted of a single treatment area without monitoring of either the pest or biodiversity. Only 2.4% of pest control actions had one or more treatment and non-treatment areas, and very few treatment and non-treatment areas (0.3%) were randomly assigned. Replication of treatment and non-treatment areas occurred in only 1.0% of pest control actions. The field of wildlife management has been strongly criticised for its slow adoption of the tenets of experimentation to examine the effects of management actions, and our results show that this criticism applies to mammalian pest control in Australia. Until the principles of experimental design are adopted, knowledge of the effects of mammalian pest control in Australia will remain unreliable.

Control of pest mammals for biodiversity protection in Australia. I. Patterns of control and monitoring

Foxes, wild dogs, feral cats, rabbits, feral pigs and feral goats are believed to have deleterious impacts on native biodiversity in Australia. However, although considerable resources have been expended controlling these six species, little is known about national patterns and costs of control and monitoring. We therefore conducted a survey of pest-control operations undertaken by conservation-focused organisations in Australia. A total of 1306 control operations were reported, with most conducted during 1998–2003: there was little information prior to 1990. Foxes and rabbits were the most, and feral cats the least, frequently controlled pest species. The total area on which control was undertaken in 2003, the year for which most information was available, ranged from ~0.4 × 104 km2 for feral cats to ~10.7 × 104 km2 for foxes. A wide range of techniques and intensities were used to control each of the six species. The estimated cost of labour expended on control in 2003 ranged from $0.4 × 106 for feral cats to $5.3 × 106 for foxes. Monitoring of the pest or biodiversity occurred in 50–56% of control actions in which foxes, wild dogs and feral cats were targeted, but only 22–26% of control actions in which rabbits, feral pigs and feral goats were targeted. Our results are discussed in relation to previous studies of pest animal control and monitoring in Australia.

284. Leukocyte trafficking in the ovary of mice immunised with recombinant murine cyclomegalovirus expressing murine zona pellucida 3

Inoculation of female BALB/c mice with recombinant murine cytomegalovirus encoding murine zona pellucida antigen (MCMV-ZP3) confers infertility characterised by depletion in ovarian tertiary follicles by day 21 post inoculation followed by a progressive depletion in primordial follicles.1 Cell mediated immune responses begin as early as day 10 post immunisation with MCMV-ZP32 with the recruitment of leukocytes before serum antibody can be clearly detected in mice. The physiological mechanisms leading to infertility in inoculated mice are being progressively delineated with the role of leukocyte subsets implicated in early pathological changes in ovarian architecture. The aim of this study was to investigate the effect of MCMV-ZP3 infection on leukocytes including T cells recruited into the ovary following infection with recombinant virus. Fifteen BALB/c female mice were randomly allocated into three groups of five animals at 6 weeks of age. Group one received an injection of PBS, group two and three received intraperitoneal inoculations of 2 × 104 pfu of MCMV and MCMV-ZP3 respectively. Ovaries were retrieved at day 10, 21 and 35 post inoculation and one ovary from each mouse was sectioned for immunohistochemical analysis of resident leukocytes using mAb CD45 reactive with all leukocyte lineages and mAb for CD4 and CD8 positive T cells. MCMV-ZP3 inoculation increased the abundance of ovarian leukocytes including CD4 and CD8 positive T cells for all time points post immunisation except for CD8 positive T cells 21 days post infection (Table 1). These results suggest that leukocytes, including T cells, are involved in causing early changes in the ovary post infection with MCMV-ZP3 that lead to the depletion of existing ovarian follicles leading to life long infertility in mice. Further experiments are underway to investigate the role of antibody and changes in leukocyte populations in the ovary as the course of infection with recombinant virus progresses. This study is funded by the Cooperative Research Centre for Pest Animal Control. (1)Lloyd ML, et al. (2003). Biol. Reprod. 68, 2024–32.(2)O’Leary S, et al. (2004). Reprod. Fertil. Devel. 16(Supplement), 77.

223.Ovarian pathology in mice following immunisation with recombinant murine cytomegalovirus expressing murine zona pellucida 3

Immunocontraception is a promising biological control for wild mice in Australia, having the potential to reduce the socioeconomic cost of plagues with minimal environmental impact. Inoculation of BALB/c mice with recombinant murine cytomegalovirus encoding murine zona pellucida antigen (mCMV-ZP3) confers total infertility characterised by depletion in ovarian tertiary follicles by Day 21 post inoculation followed by a progressive depletion in primordial follicles (1). The mechanisms underlying ovarian pathology are largely unknown but are likely to involve antibody mediated and cell mediated immune responses. The immune pathology may also be facilitated by acute responses involving antibody binding to ZP in growing follicles resulting in recruitment of inflammatory cells and oocyte destruction. The aim of this study was to investigate the effect of mCMV–ZP3 infection on leukocyte infiltration and expression of oocyte-derived signalling molecules in ovarian tissue. Fifteen BALB/c female mice were randomly allocated into three groups of 5 animals. Group one received an injection of PBS, group two and three received intraperitoneal inoculations of 2�×�104�p.f.u. of mCMV and mCMV-ZP3 respectively. Ovaries were retrieved at Day 7 post inoculation and one ovary from each mouse was sectioned for immunohistochemical analysis of resident leukocytes using mAb CD45 reactive with all leukocyte lineages. The other ovary was processed for real time quantitative RT-PCR analysis of growth and differentiation factor 9 (GDF-9) and connexin 43 (Cx43) expression. mCMV-ZP3 inoculation increased the abundance of ovarian leukocytes (P�=�0.08), significantly increased expression of Cx43 mRNA (p<0.05), but did not alter GDF-9 mRNA expression. These results suggest that changes in expression of ovarian regulators due to ZP3 immunisation begins early after recombinant MCMV infection in mice, and implicates leukocyte infiltration in the mechanism leading to permanent ovarian failure. Further experiments are underway to investigate the dynamics of leukocyte trafficking and expression of oocyte-derived signals as the course of infection progresses. This study is funded by the Cooperative Research Centre for Pest Animal Control. (1) Lloyd, M. L., et al. (2003). Biology of Reproduction 68(6): 2024-32.

Biotech prospects for the control of introduced mammals in Australia.

More than twenty exotic vertebrate species are now listed as pests in Australia. Collectively, these pests have a huge economic and environmental impact and pose a major threat to Australia's ecosystems and unique biodiversity. Management of such pests on a continental scale is a major challenge. Recent advances in biotechnology suggest alternatives to the lethal diseases normally sought for use as biological control agents. One proposal, being investigated in the Pest Animal Control Cooperative Research Centre, Canberra, is the use of biotechnology to develop a new generation of agents that act through controlling reproduction to prevent the build up of pest populations. The core concept is fertility control through immunocontraceptive vaccines delivered by viruses that specifically infect the target pest population. Proof of this exciting concept has been obtained for the mouse and, very recently, the rabbit, and a candidate vaccine vector identified for the fox, portending better control of a trio of Australia's most pervasive pests. Other advances in biotechnology suggest ways to negate the build up of both innate and acquired immune resistance in target pest populations that normally act to limit the efficacy and effective life of biocontrol agents in the field. Prospects for extending the use of virally vectored vaccines to the field management of wildlife diseases are also identified. Targets for such vaccines include a growing suite of emerging diseases, hosted by Australia's wildlife, which pose a threat to human and livestock health. Numerous technical challenges remain to be addressed before any of these new agents are ready for use in the field. However, the major risk to their development is now no longer viewed as being technical, but the failure to gain public acceptance for their use in the field. This already significant risk is exasperated by the present heightened level of public concern about all introductions of genetically modified organisms.