The ethics of rodent control

Exposure to anticoagulant rodenticides in steppe polecat (Mustela eversmanii) and European polecat (Mustela putorius) in central Europe

Poisoning caused by coumarin-type anticoagulant rodenticides (ARs) stands as the predominant method for controlling rodents globally. ARs, through secondary poisoning, pose a significant threat to predators due to their lethal and sublethal effects. We examined the concentration of accumulated ARs in liver samples of mostly road-killed steppe polecats (Mustela eversmanii) and European polecats (M. putorius) collected throughout Hungary between 2005 and 2021. The steppe polecat samples were found mainly from Eastern Hungary, while European polecats from Western Hungary. We measured the concentration of six residues by HPLC-FLD. Our analysis revealed the presence of one first-generation and four second-generation ARs in 53% of the steppe polecat (36) and 39% of the European polecat (26) samples. In 17 samples we detected the presence of at least two AR compounds. Although we did not find significant variance in AR accumulation between the two species, steppe polecats displayed greater prevalence and maximum concentration of ARs, whereas European polecat samples exhibited a more diverse accumulation of these compounds. Brodifacoum and bromadiolone were the most prevalent ARs; the highest concentrations were 0.57 mg/kg and 0.33 mg/kg, respectively. The accumulation of ARs was positively correlated with human population density and negatively correlated with the extent of the more natural habitats in both species. To the best of our knowledge, this is the first study to demonstrate anticoagulant rodenticide exposure in steppe polecats globally, and for European polecats in Central European region. Although the extent of AR accumulation in European polecat in Hungary appears comparatively lower than in many other European countries, the issue of secondary poisoning remains a serious problem as these ARs intrude into food webs. Reduced and more prudent usage of pesticides would provide several benefits for wildlife, included humans. However, we advocate a prioritization of ecosystem services through the complete prohibition of the toxicants.

The Animal Welfare Consequences and Moral Implications of Lethal and Non-Lethal Fox Control Methods

Control methods are applied worldwide to reduce predation on livestock by European red foxes (Vulpes vulpes). Lethal methods can inflict suffering; however, moral debate about their use is lacking. Non-lethal methods can also inflict suffering and can unintentionally lead to death, and yet both the welfare consequences and ethical perspectives regarding their use are rarely discussed. The aim of this study was to investigate the animal welfare consequences, the level of humaneness, the ethical considerations and the moral implications of the global use of fox control methods according to Tom Regan's animal rights view and Peter Singer's utilitarian view. According to Regan, foxes ought not to be controlled by either lethal or potentially harmful non-lethal methods because this violates the right of foxes not to be harmed or killed. According to Singer, if an action maximises happiness or the satisfaction of preferences over unhappiness or suffering, then the action is justified. Therefore, if and only if the use of fox control methods can prevent suffering and death in livestock in a manner that outweighs comparable suffering and death in foxes is one morally obligated to use them. It is clear that lethal fox control methods and some non-lethal methods are inhumane.

Attitudes of clients of Dutch pest controllers towards integrated pest management (IPM) and preventive measures in relation to rodent nuisance

BACKGROUND

Rodent management with lethal methods (e.g., rodenticides) comes with downsides for rodent welfare, the environment and non-target species. To reduce chemical use and prevent rodent nuisance, pest controllers in the Netherlands must work according to the principles of integrated pest management (IPM). A condition for the success of IPM is that there is sufficient engagement of all parties involved, including clients of pest controllers. The aim of this study was to gain insight into the attitudes of clients regarding rodent control, IPM and the application of preventive measures. Insight into their attitudes may contribute to a better implementation of IPM and with that to a more sustainable rodent management based on more effective prevention. An online survey among 248 clients of Dutch pest controllers from both the agricultural and other sectors was carried out.

RESULTS

Respondents from the agricultural sector had a relatively negative attitude towards IPM, the new IPM regulations in the Netherlands and had little confidence in prevention. In other sectors, respondents were more positive about IPM and had more confidence in prevention. The respondents from the latter subgroup had a similar attitude compared to Dutch pest controllers who participated in a previous survey.

CONCLUSION

The findings of the study provide information for the further development and practical implementation of IPM and preventive measures and with that a more sustainable and animal friendly rodent management. They can also be helpful for a better communication and cooperation between pest controllers and their clients. © 2024 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

SARS-CoV-2 Surveillance of Wild Mice and Rats in North American Cities

From July 2020 to June 2021, 248 wild house mice (Mus musculus), deer mice (Peromyscus maniculatus), brown rats (Rattus norvegicus), and black rats (Rattus rattus) from Texas and Washington, USA, and British Columbia, Canada, were tested for SARS-CoV-2 exposure and infection. Two brown rats and 11 house mice were positive for neutralizing antibodies using a surrogate virus neutralization test, but negative or indeterminate with the Multiplexed Fluorometric ImmunoAssay COVID-Plex, which targets full-length spike and nuclear proteins. Oro-nasopharyngeal swabs and fecal samples tested negative by RT-qPCR, with an indeterminate fecal sample in one house mouse. Continued surveillance of SARS-CoV-2 in wild rodents is warranted.

Attitudes of clients of Dutch pest controllers towards animal welfare in the management of liminal rodents

Rodent control tends to involve methods that cause animal suffering, but little attention has been paid to the animal welfare implications of rodent control. The aim of the current study was to gain insight into the opinions and attitudes of clients of Dutch pest controllers, regarding liminal rodents, rodent control, and rodent welfare. A better understanding of their attitudes may contribute to more ethical rodent management programmes. An online survey among 248 clients of Dutch pest controllers was carried out. Respondents, especially those within the agricultural sector, have a relatively negative attitude towards rats and mice. Respondents in the agricultural subgroup do not consider the welfare of liminal rodents important. They also think that the welfare impact of commonly used control methods is limited, and they have low tolerance levels for the presence of rodents. Respondents from other sectors have a far more positive attitude towards rats and mice, consider their welfare to be of greater importance, have a greater estimation of the welfare impact of control methods and show greater tolerance levels towards rodents. The respondents from the latter subgroup have a similar attitude compared to Dutch pest controllers participating in a previous survey. The findings of the current study firstly provide useful information for the further development and practical implementation of preventive control methods. Secondly, they provide input for a more animal-friendly rodent control and for the development of an assessment framework to support ethical decision-making. Finally, they can be helpful for further research and the communication and co-operation between professional pest controllers and their clients.

A Systematic Review and Meta-Analysis of the Inhibitory Effects of Plant-Derived Sterilants on Rodent Population Abundance

Owing to their low minimal environmental risk and other ethical considerations, plant-derived sterilants are used to control rodent populations. However, the effects of plant-derived sterilants are not immediate, and their efficacy on rodent control is controversial, which negatively affects sterilant research and application. Here, a meta-analysis of the available literature was conducted to evaluate the effects of two plant-derived sterilants, triptolide and curcumol, on rodent populations. Using a random-effects and a fixed-effects model, we calculated the weighted mean difference (WMD) and relative risk (RR) and their corresponding 95% confidence intervals (95% CIs). After the application of plant-derived sterilants, the rodent population density tended to decrease. Three outcome-related measures in rodents, i.e., capture rate (RR = 0.31, 95% CI [0.20, 0.47]), pregnancy rate (RR = 0.49, 95% CI [0.40, 0.61]), and sperm survival rate (WMD = −17.53, 95% CI [−28.96, −6.06]), significantly decreased, as shown by a significant reduction of ovarian, uterine, and testicular organ coefficients. However, the number of effective rodent holes did not change significantly after the interventions, indicating that the studied sterilants did not directly eradicate the rodent populations. This study provides a theoretical basis for elucidating the inhibitory mechanisms of plant-derived sterilants on rodent populations and for the rational use of these sterilants.

Rapid method for the detection of rodenticides in contaminated foods

Rodenticides are toxic chemicals used to control rodent populations and are among the most common household toxicants. Ingestion of foods contaminated with rodenticides may cause severe illness or death in humans and animals. A rapid analytical method was developed for the identification of nine common rodenticides in foods using solid-liquid extraction followed by dispersive-solid phase extraction prior to the analysis by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and UV detection. The method validation on a variety of food matrices including cornmeal, peanut, whole wheat flour and pork liver produced average recoveries between 91.2 and 107% with relative standard deviations between 2.6 and 14% for all studied rodenticides. The method detection limits ranged from 2.7 to 8.2 μg/kg (ppb) for eight rodenticides analyzed by LC-MS/MS and between 0.10 and 0.21 mg/kg (ppm) for bromethalin which was analyzed by LC with UV detection. This method could be useful in preparedness for emergency response situations involving widespread food contamination, terrorist acts or for forensic studies.

Crop protection practices and viral zoonotic risks within a One Health framework

Recent viral zoonotic epidemics have been attributed partially to the negative impact of human activities on ecosystem biodiversity. Agricultural activities, particularly conventional crop protection (CP) practices, are a major threat to global biodiversity, ecosystem health and human health. Here we review interactions between CP practices and viral zoonoses (VZs), the first time this has been done. It should be noted that a) VZs stand at the interface between human, animal and ecosystem health; b) some VZs involve arthropod vectors that are affected by CP practices; and c) some crop pests, or their natural enemies are vertebrate reservoirs/carriers of certain VZs, and their contact with humans or domestic animals is affected by CP practices. Our review encompasses examples highlighting interactions between VZs and CP practices, both efficiency improvement-based (i.e. conventional with agrochemical insecticides and rodenticides), substitution-based (i.e. mainly with physical/mechanical or biopesticidal pest control), and redesign-based (i.e. mainly with conservation biological pest control, including some forms of crop-livestock integration). These CP practices mainly target arthropod and vertebrate pests. They also target, to a lesser extent, weeds and plant pathogens. Conventional and some physical/mechanical control methods and some forms of biopesticidal and crop-livestock integration practices were found to have mixed outcomes in terms of VZ risk management. Conversely, practices based on biological control by habitat conservation of arthropod or vertebrate natural enemies, falling within the Agroecological Crop Protection (ACP) framework, result in VZ prevention at various scales (local to global, and short-term to long-term). ACP addresses major global challenges including climate resilience, biodiversity conservation and animal welfare, and helps integrate plant health within the extended "One Health" concept.

Early life malnutrition and fluctuating asymmetry in the rat bony labyrinth

Maternal malnutrition during gestation and lactation is known to have adverse effects on offspring. We evaluate the impact of maternal diet on offspring bony labyrinth morphology. The bony labyrinth develops early and is thought to be stable to protect vital sensory organs within. For these reasons, bony labyrinth morphology has been used extensively to assess locomotion, hearing function, and phylogeny in primates and numerous other taxa. While variation related to these parameters has been documented, there is still a component of intraspecific variation that is unexplained. Although the labyrinthine developmental window is small, it may provide the opportunity for developmental instability to produce corresponding shape differences, as measured by fluctuating asymmetry (FA). We hypothesized that (a) offspring with poor maternal diet would exhibit increased FA, but (b) no unilateral shape difference. To test these hypotheses, we used two groups of rats (Rattus norvegicus; Crl:WI[Han] strain), one control group and one group exposed to a isocaloric, protein-restricted maternal diet during gestation and suckling. Individuals were sampled at weaning, sexual maturity, and old age. A Procrustes analysis of variance identified statistically significant FA in all diet-age subgroups. No differences in level of FA were identified among the subgroups, rejecting our first hypothesis. A principal components analysis identified no unilateral shape differences, supporting our second hypothesis. These results indicate that bony labyrinth morphology is remarkably stable and likely protected from a poor maternal diet during development. In light of this result, other factors must be explored to explain intraspecific variation in labyrinthine shape.

Dilemmas in the Management of Liminal Rodents-Attitudes of Dutch Pest Controllers

Simple Summary

Most people think the welfare of non-human animals matters. However, when it comes to rats and mice labeled as ‘pests’, welfare generally appears less important. Together with stakeholders in the field of pest management, we are working to develop a framework for less harmful rodent control that can be used by pest controllers. An online survey was carried out in order to find out to what extent Dutch pest controllers take the welfare of rats and mice into account as part of their profession. Our findings show that respondents pay attention to animal welfare and believe that some methods used cause severe animal suffering. Also, they think there are situations in which more attention for preventive methods (e.g., cleaning, removing food sources, or closing holes in a building) benefits both humans and pest animals. They indicate, however, that it is sometimes hard to include animal welfare in their work. An important reason for this is that clients do not always want to invest sufficient money in prevention. The findings of this study are useful for further conversations with pest controllers and their clients on how to safeguard animal welfare. Furthermore, they are relevant to the framework we are developing.

Abstract

When non-human animals are labeled as ‘pests’, their moral status and welfare seem relatively unimportant. In a multi-stakeholder project, we develop an assessment frame for a more responsible rodent management that includes animal welfare. An online survey among 129 Dutch pest controllers was carried out in order to find out more about pest controllers’ attitudes about animal welfare. Respondents indicate to consider animal welfare in their job. They see differences in the welfare impact of different rodent control methods. A dilemma may occur when methods with a high impact, such as rodenticides, are ofttimes used in practice. Respondents also indicate that in different real-life scenarios (the hospital kitchen vs. the private backyard), a different weight may be attributed to the importance of animal welfare. Almost half of the respondents encounter difficulties when weighing animals against human interests. The problems are mainly related to clients who are not willing to invest sufficient money in preventive methods, where respondents do believe in. Some differences were found between respondents depending on membership of a professional association for pest controllers. The results of this study are relevant input for focus groups with pest controllers and their clients and for the development of the aforementioned assessment frame.

Biodefense Implications of New-World Hantaviruses

Hantaviruses, part of the Bunyaviridae family, are a genus of negative-sense, single-stranded RNA viruses that cause two major diseases: New-World Hantavirus Cardiopulmonary Syndrome and Old-World Hemorrhagic Fever with Renal Syndrome. Hantaviruses generally are found worldwide with each disease corresponding to their respective hemispheres. New-World Hantaviruses spread by specific rodent-host reservoirs and are categorized as emerging viruses that pose a threat to global health and security due to their high mortality rate and ease of transmission. Incidentally, reports of Hantavirus categorization as a bioweapon are often contradicted as both US National Institute of Allergy and Infectious Diseases and the Centers for Disease Control and Prevention refer to them as Category A and C bioagents respectively, each retaining qualitative levels of importance and severity. Concerns of Hantavirus being engineered into a novel bioagent has been thwarted by Hantaviruses being difficult to culture, isolate, and purify limiting its ability to be weaponized. However, the natural properties of Hantaviruses pose a threat that can be exploited by conventional and unconventional forces. This review seeks to clarify the categorization of Hantaviruses as a bioweapon, whilst defining the practicality of employing New-World Hantaviruses and their effect on armies, infrastructure, and civilian targets.

Understanding conservation conflicts associated with rodent outbreaks in farmland areas

Rodent outbreaks affect many farmland areas worldwide and the negative environmental impacts of control campaigns cause intense social tensions. In such conservation conflicts, understanding stakeholders' viewpoints is critical to promote ecologically sustainable management. We used Q-methodology, a framework standing between qualitative and quantitative social research, to investigate human subjectivity and understand conflicts caused by rodent outbreaks in Spain. We interviewed farmers, conservationists, hunters, and governmental agencies, and identified five main discourses about the origins and consequences of the conflictive situation. Finding sustainable management is impaired by opposing views about causes and consequences of vole outbreaks and their management, which are at the root of the conflict. Social tensions will likely remain until the underlying conflicts between people holding different views are also managed. Decision-making should therefore focus on mitigating underlying conflicts. Using trained independent mediators would help the effective resolution of conservation conflicts caused by rodent outbreaks and their management.

The social life of Norway rats (Rattus norvegicus)

The Norway rat has important impacts on our life. They are amongst the most used research subjects, resulting in ground-breaking advances. At the same time, wild rats live in close association with us, leading to various adverse interactions. In face of this relevance, it is surprising how little is known about their natural behaviour. While recent laboratory studies revealed their complex social skills, little is known about their social behaviour in the wild. An integration of these different scientific approaches is crucial to understand their social life, which will enable us to design more valid research paradigms, develop more effective management strategies, and to provide better welfare standards. Hence, I first summarise the literature on their natural social behaviour. Second, I provide an overview of recent developments concerning their social cognition. Third, I illustrate why an integration of these areas would be beneficial to optimise our interactions with them.

Anticoagulant Rodenticides, Islands and Animal Welfare Accountancy

Simple Summary

Anticoagulant rodenticides are a mainstay of rodent management in many domestic, municipal, agricultural, and conservation settings. Anticoagulant poisoning has poor welfare outcomes for mammals and birds and, worldwide, this means potentially very large numbers of animals are poisoned annually consequent (intended or not) to rodenticide use. Critical differences in use patterns of anticoagulants applied for ongoing rodent control, versus application for rodent eradication especially on islands, have clear implications for animal welfare costs measured as cumulative number of animals affected over time. Here we outline these differences and discuss how animal welfare considerations can be weighed in decisions to use anticoagulant rodenticides for island eradication attempts.

Abstract

Anticoagulant rodenticides are used to manage rodents in domestic, municipal, agricultural, and conservation settings. In mammals and birds, anticoagulant poisoning causes extensive hemorrhagic disruption, with the primary cause of death being severe internal bleeding occurring over days. The combined severity and duration of these effects represent poor welfare outcomes for poisoned animals. Noting a lack of formal estimates of numbers of rodents and nontarget animals killed by anticoagulant poisoning, the ready availability and worldwide use of anticoagulants suggest that very large numbers of animals are affected globally. Scrutiny of this rodent control method from scientific, public, and regulatory perspectives is being driven largely by mounting evidence of environmental transfer of residual anticoagulants resulting in harmful exposure in wild or domestic animals, but there is also nascent concern for the welfare of targeted rodents. Rodent control incurs a cumulative ledger of animal welfare costs over time as target populations reduced by poisoning eventually recover to an extent requiring another reduction. This ‘rolling toll’ presents a critical contrast to the animal welfare accountancy ledger for eradication scenarios, where rodent populations can be completely removed by methods including anticoagulant use and then kept from coming back (e.g., on islands). Successful eradications remove any future need to control rodents and to incur the associated animal welfare costs.

Understanding Preferences for Humane and Cruel Treatment of Pest Rodents in Site C, Khayelitsha, South Africa

The cruel treatment of pest rodents is a neglected area of study. This paper uses a representative survey from Khayelitsha (Cape Town) to show that a minority of residents preferred rodent control to be humane but that most did not care how rats are killed and almost a fifth said they would be 'happy' if the rats suffered. Agreeing that animal welfare is important and having become used to the presence of rats raised the probability of support for humane rodent control and decreased support for cruel rodent control. Being concerned that rats might be linked to witchcraft increased the probability of a pro-cruel stance. These results were robust to the inclusion of measures of rodent presence in the household and socio-economic status. This highlights the importance of values (notably concern about animal welfare) and cultural beliefs - in this case concerns that rodents might be linked to witchcraft - in predicting whether respondents are likely to have a pro-cruel stance on rodent control or not. Promoting the humane treatment of pest animals in this context thus requires engaging with local culture.

The Dividing Line Between Wildlife Research and Management-Implications for Animal Welfare

Wild animals are used for research and management purposes in Sweden and throughout the world. Animals are often subjected to similar procedures and risks of compromised welfare from capture, anesthesia, handling, sampling, marking, and sometimes selective removal. The interpretation of the protection of animals used for scientific purposes in Sweden is based on the EU Directive 2010/63/EU. The purpose of animal use, irrespective if the animal is suffering or not, decides the classification as a research animal, according to Swedish legislation. In Sweden, like in several other European countries, the legislation differs between research and management. Whereas, animal research is generally well-defined and covered in the legislation, wildlife management is not. The protection of wild animals differs depending on the procedure they are subjected to, and how they are classified. In contrast to wildlife management activities, research projects have to implement the 3Rs and must undergo ethical reviews and official animal welfare controls. It is often difficult to define the dividing line between the two categories, e.g., when marking for identification purposes. This gray area creates uncertainty and problems beyond animal welfare, e.g., in Sweden, information that has been collected during management without ethical approval should not be published. The legislation therefore needs to be harmonized. To ensure consistent ethical and welfare assessments for wild animals at the hands of humans, and for the benefit of science and management, we suggest that both research and management procedures are assessed by one single Animal Ethics Committee with expertise in the 3Rs, animal welfare, wildlife population health and One Health. We emphasize the need for increased and improved official animal welfare control, facilitated by compatible legislation and a similar ethical authorization process for all wild animal procedures.

Animal welfare and ecology in the contested ethics of rodent control in Cape Town

There is growing concern globally about the inhumane treatment of ‘pest’ animals, including rodents, and about the ecological consequences of rodenticides, notably the poisoning of non-target wildlife like raptors and scavengers. Recent contestation between Environmental Health (EH) officials in Khayelitsha, Cape Town’s largest African township, and the National Council for Societies for the Prevention of Cruelty to Animals (NSPCA) illustrates the tension that can arise between innovative ecologically-focused strategies and existing legislation and animal protection practices. In 2013/14 EH officials introduced a job-creation project to trap and drown rats, describing it as ‘humane’ because it avoided poison thereby posing no danger to wildlife such as owls. The NSPCA, however, halted the project, arguing that drowning was both inhumane and illegal. Death by poison is also inhumane but the South Africa’s Animals Protection Act (1962) allows it (and trapping and hunting) to be used against ‘pests’/‘vermin’. The NSPCA, which has never challenged the Act for allowing the inhumane treatment of these animals, used it to trump local preferences. A representative survey from Khayelitsha showed that there was some support for an NSPCA-like position (14% thought that drowning was cruel and that workers should not be allowed to trap and drown rats) but that the majority (70%) indicated that they were both concerned about the poisoning of non-target animals and supported the continuation of the trapping and drowning project. This was not a contestation over whether animals should be protected, but over how to do this, and which animals to include.

The need to implement the landscape of fear within rodent pest management strategies

Current reactive pest management methods have serious drawbacks such as the heavy reliance on chemicals, emerging genetic rodenticide resistance and high secondary exposure risks. Rodent control needs to be based on pest species ecology and ethology to facilitate the development of ecologically based rodent management (EBRM). An important aspect of EBRM is a strong understanding of rodent pest species ecology, behaviour and spatiotemporal factors. Gaining insight into the behaviour of pest species is a key aspect of EBRM. The landscape of fear (LOF) is a mapping of the spatial variation in the foraging cost arising from the risk of predation, and reflects the levels of fear a prey species perceives at different locations within its home range. In practice, the LOF maps habitat use as a result of perceived fear, which shows where bait or traps are most likely to be encountered and used by rodents. Several studies have linked perceived predation risk of foraging animals with quitting-harvest rates or giving-up densities (GUDs). GUDs have been used to reflect foraging behaviour strategies of predator avoidance, but to our knowledge very few papers have directly used GUDs in relation to pest management strategies. An opportunity for rodent control strategies lies in the integration of the LOF of rodents in EBRM methodologies. Rodent management could be more efficient and effective by concentrating on those areas where rodents perceive the least levels of predation risk. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Control of invasive rats on islands and priorities for future action

Invasive rats are one of the world's most successful animal groups that cause native species extinctions and ecosystem change, particularly on islands. On large islands, rat eradication is often impossible and population control, defined as the local limitation of rat abundance, is now routinely performed on many of the world's islands as an alternative management tool. However, a synthesis of the motivations, techniques, costs, and outcomes of such rat-control projects is lacking. We reviewed the literature, searched relevant websites, and conducted a survey via a questionnaire to synthesize the available information on rat-control projects in island natural areas worldwide to improve rat management and native species conservation. Data were collected from 136 projects conducted over the last 40 years; most were located in Australasia (46%) and the tropical Pacific (25%) in forest ecosystems (65%) and coastal strands (22%). Most of the projects targeted Rattus rattus and most (82%) were aimed at protecting birds and endangered ecosystems. Poisoning (35%) and a combination of trapping and poisoning (42%) were the most common methods. Poisoning allows for treatment of larger areas, and poison projects generally last longer than trapping projects. Second-generation anticoagulants (mainly brodifacoum and bromadiolone) were used most often. The median annual cost for rat-control projects was US$17,262 or US$227/ha. Median project duration was 4 years. For 58% of the projects, rat population reduction was reported, and 51% of projects showed evidence of positive effects on biodiversity. Our data were from few countries, revealing the need to expand rat-control distribution especially in some biodiversity hotspots. Improvement in control methods is needed as is regular monitoring to assess short- and long-term effectiveness of rat-control.

Welfare Impacts of Pindone Poisoning in Rabbits (Oryctolagus cuniculus)

Control methods used to manage unwanted impacts of the European rabbit in Australia and New Zealand include the use of toxic bait containing the anticoagulant pindone. Towards increased certainty in evaluating the animal welfare impacts of pindone poisoning in rabbits, we recorded behavioral and post-mortem data from rabbits which ingested lethal quantities of pindone bait in a laboratory trial. Pindone poisoning in rabbits resulted in welfare compromise, primarily through functional impairments related to internal haemorrhage over a maximum duration of 7 days. Applying this data to a formal assessment framework for ranking animal welfare impacts indicated that pindone had relatively high severity and also duration of welfare impacts in comparison to other rabbit control methods.

Assessing Animal Welfare Impacts in the Management of European Rabbits (Oryctolagus cuniculus), European Moles (Talpa europaea) and Carrion Crows (Corvus corone)

Human-wildlife conflict is a global issue. Attempts to manage this conflict impact upon wild animal welfare, an issue receiving little attention until relatively recently. Where human activities harm animal welfare these effects should be minimised where possible. However, little is known about the welfare impacts of different wildlife management interventions, and opinions on impacts vary widely. Welfare impacts therefore need to be assessed objectively. Our objectives were to: 1) establish whether an existing welfare assessment model could differentiate and rank the impacts of different wildlife management interventions (for decision-making purposes); 2) identify and evaluate any additional benefits of making formal welfare assessments; and 3) illustrate issues raised by application of the model. We applied the welfare assessment model to interventions commonly used with rabbits (Oryctolagus cuniculus), moles (Talpa europaea) and crows (Corvus corone) in the UK. The model ranked interventions for rabbits (least impact first: fencing, head shot, chest shot) and crows (shooting, scaring, live trapping with cervical dislocation). For moles, managing molehills and tunnels scored least impact. Both spring trapping, and live trapping followed by translocation, scored greater impacts, but these could not be compared directly as they scored on different axes of the model. Some rankings appeared counter-intuitive, highlighting the need for objective formal welfare assessments. As well as ranking the humaneness of interventions, the model highlighted future research needs and how Standard Operating Procedures might be improved. The model is a milestone in assessing wildlife management welfare impacts, but our research revealed some limitations of the model and we discuss likely challenges in resolving these. In future, the model might be developed to improve its utility, e.g. by refining the time-scales. It might also be used to reach consensus among stakeholders about relative welfare impacts or to identify ways of improving wildlife management practice in the field.

Evidence that rodent control strategies ought to be improved to enhance food security and reduce the risk of rodent-borne illnesses within subsistence farming villages in the plague-endemic West Nile region, Uganda

Rodents pose serious threats to human health and economics, particularly in developing countries where the animals play a dual role as pests: they are reservoirs of human pathogens, and they inflict damage levels to stored products sufficient to cause food shortages. To assess the magnitude of the damage caused by rodents to crops, their level of contact with humans, and to better understand current food storage and rodent control practices, we conducted a survey of 37 households from 17 subsistence farming villages within the West Nile region of Uganda. Our survey revealed that rodents cause both pre- and post-harvest damage to crops. Evidence of rodent access to stored foods was reported in conjunction with each of the reported storage practices. Approximately half of the respondents reported that at least one family member had been bitten by a rat within the previous three months. Approximately two-thirds of respondents practiced some form of rodent control in their homes. The abundance of rodents was similar within homes that practiced or did not practice rodent control. Together, our results show that current efforts are inadequate for effectively reducing rodent abundance in homes.

Combining aspirin with cholecalciferol (vitamin D3)--a potential new tool for controlling possum populations

The introduced Australian brushtail possum is a major vertebrate pest in New Zealand, with impacts on conservation and agriculture being managed largely through poisoning operations. Cholecalciferol (vitamin D3) is registered for use in controlling possums and despite its many advantages it is expensive and relatively inhumane. Combination of a high proportion of aspirin with a low proportion of cholecalciferol was effective in killing high proportions of groups of acclimatised, caged possums: this is attributed to both an unexpectedly high toxicity of the type of cholecalciferol used, and a proposed synergistic mechanism between the two compounds. Death was caused by localised damage to heart ventricles by aspirin, and inhibition of tissue repair by both aspirin and cholecalciferol. The observed toxicosis had lower impact on the welfare of possums than either compound administered alone, particularly aspirin alone. Residue analyses of bait remains in the GI tract suggested a low risk of secondary poisoning by either compound. The combination of cholecalciferol and aspirin has the potential to meet key requirements of cost-effectiveness and humaneness in controlling possum populations, but the effect of the combination in non-target species has yet to be tested.

Understanding attitudes toward the control of nonnative wild and feral mammals: similarities and differences in the opinions of the general public, animal protectionists, and conservationists in New Zealand (aotearoa)

Lethal control is used extensively in New Zealand to control nonnative nonhuman mammals. Respondents were surveyed about 8 mammal groups considered pests and their attitudes toward their control and pest status. They also identified the most appropriate method of control for the 8 different mammals. Information was gathered from 3 groups of respondents: nonhuman animal protectionists, conservationists, and the general public. Conservationists routinely rated all animal groups as more severe pests than the general public or animal protectionists, who provided the lowest scores. Rats, stoats, brushtail possums, and rabbits were identified as the 4 most serious pests by all 3 groups. Conservationists were 5.7 and 2.6 times more likely to prefer a lethal method of control than protectionists and the general public, respectively. For all 3 groups an increase in pest score for a given animal saw a decline in importance placed upon the animal's welfare. This relationship was strong for the general public but weak for conservationists and animal protectionists. Understanding aspects of potentially opposing viewpoints may be invaluable in supporting the development of new welfare-focused control methods.

Ethical Considerations in Mouse Experiments

Mice count morally because they can be harmed. This raises a moral issue in animal experimentation. Three main ethical attitudes towards animals are reviewed here. The Kantian view denies moral value to animals because they lack reason. The second view, by Singer, considers animals as sentient creatures (i.e., able to suffer). Finally, Regan considers that animals are subjects of their own life; they are autonomous and therefore have moral rights. Singer is a reformist and allows animal experimentation under certain conditions. Regan is abolitionist, saying that animals have moral rights that cannot be negotiated. Current animal protection legislation strives to put in balance the human and animal interests to decide whether an animal experiment is morally justified or not. An ethical evaluation process is conducted based on the harm-benefit assessment of the experiment. The researcher has to implement the 3Rs (Replacement, Reduction, Refinement) to minimize the harms to the animals and make sure that the outcomes are scientifically significant and that the quality of the science is high, in order to maximize benefits to humans and animals. Curr. Protoc. Mouse Biol. 1:155-167. © 2011 by John Wiley & Sons, Inc.

What can pest management learn from laboratory animal ethics?

There remains a lack of a clear overarching policy framework for decision-making in pest control programmes. In comparison, ethical principles have been extensively developed for scientific procedures, such as those underlying the UK's Animals (Scientific Procedures) Act 1986. This paper assesses the extent to which the principles and methodology underlying the act and secondary guidance could be used to provide principles of rodent management. Useful principles include that any programme has a legitimate purpose; that methods are used only if the harms are outweighed by the benefits; that harms are minimised by refinement, replacement and reduction and that there is personal responsibility. The usefulness and implications for pest control of each principle and the overall approach are discussed.