Why humans kill animals and why we cannot avoid it.

Killing animals has been a ubiquitous human behaviour throughout history, yet it is becoming increasingly controversial and criticised in some parts of contemporary human society. Here we review 10 primary reasons why humans kill animals, discuss the necessity (or not) of these forms of killing, and describe the global ecological context for human killing of animals. Humans historically and currently kill animals either directly or indirectly for the following reasons: (1) wild harvest or food acquisition, (2) human health and safety, (3) agriculture and aquaculture, (4) urbanisation and industrialisation, (5) invasive, overabundant or nuisance wildlife control, (6) threatened species conservation, (7) recreation, sport or entertainment, (8) mercy or compassion, (9) cultural and religious practice, and (10) research, education and testing. While the necessity of some forms of animal killing is debatable and further depends on individual values, we emphasise that several of these forms of animal killing are a necessary component of our inescapable involvement in a single, functioning, finite, global food web. We conclude that humans (and all other animals) cannot live in a way that does not require animal killing either directly or indirectly, but humans can modify some of these killing behaviours in ways that improve the welfare of animals while they are alive, or to reduce animal suffering whenever they must be killed. We encourage a constructive dialogue that (1) accepts and permits human participation in one enormous global food web dependent on animal killing and (2) focuses on animal welfare and environmental sustainability. Doing so will improve the lives of both wild and domestic animals to a greater extent than efforts to avoid, prohibit or vilify human animal-killing behaviour.

Updating the AIHTS Trapping Standards to Improve Animal Welfare and Capture Efficiency and Selectivity.

In 1999, after pressure from the European Union, an Agreement on International Humane Trapping Standards (AIHTS) that would result in the banning of the steel-jawed leghold traps in the European Community, Canada, and Russia was signed. The United States implemented these standards through an Agreed Minute with the European Community. Over the last two decades, scientists have criticized the AIHTS for (1) omitting species that are commonly trapped; (2) threshold levels of trap acceptance that are not representative of state-of-the-art trap technology; (3) excluding popular traps which are commonly used by trappers although they are known to cause prolonged pain and stress to captured animals; (4) inadequate coverage of capture efficiency and species selectivity (i.e., number of captures of target and non-target species) performance. Concerns about the ability of standards and test procedures to ensure animal welfare, and about the implementation of standards, have also been voiced by wildlife biologists, managers, and conservation groups. In this review, we present a synopsis of current trapping standards and test procedures, and we compare the standards to a then contemporary 1985-1993 Canadian trap research and development program. On the basis of the above-noted concerns about AIHTS, and our experience as wildlife professionals involved in the capture of mammals, we formulated the following hypotheses: (1) the list of mammal species included in the AIHTS is incomplete; (2) the AIHTS have relatively low animal welfare performance thresholds of killing trap acceptance and do not reflect state-of-the-art trapping technology; (3) the AIHTS animal welfare indicators and injuries for restraining traps are insufficient; (4) the AIHTS testing procedures are neither thorough nor transparent; (5) the AIHTS protocols for the use of certified traps are inadequate; (6) the AIHTS procedures for the handling and dispatching of animals are nonexistent; (7) the AIHTS criteria to assess trap capture efficiency and species selectivity are inappropriate. We conclude that the AIHTS do not reflect state-of-the-art trapping technology, and assessment protocols need to be updated to include trap components and sets, animal handling and dispatching, and trap visit intervals. The list of traps and species included in the standards should be updated. Finally, the concepts of capture efficiency and trap selectivity should be developed and included in the standards. Based on our review, it is clear that mammal trapping standards need to be revisited to implement state-of-the-art trapping technology and improve capture efficiency and species selectivity. We believe that a committee of international professionals consisting of wildlife biologists and veterinarians with extensive experience in the capture of mammals and animal welfare could produce new standards within 1-2 years. We propose a series of measures to fund trap testing and implement new standards.

Correction: Publication reform to safeguard wildlife from researcher harm.

[This corrects the article DOI: 10.1371/journal.pbio.3000193.].

Killing Traps and Snares in North America: The Need for Stricter Checking Time Periods.

In this review, we make the point that current checking times for killing traps and snares are inadequate or nonexistent in most North American jurisdictions. We use Conibear 120 rotating-jaw traps and killing neck snares as examples of trapping devices that may fail to consistently and humanely kill furbearers. Because these killing devices are not powerful enough for the target species, the trigger systems do not properly position the animals in traps, or trappers are inexperienced and improperly set traps or snares, these killing devices become restraining devices, and animals suffer long and painful deaths. Because trappers use a variety of trigger configurations and trap sets, all killing devices, even those certified by trapper organizations or governments, should be monitored at least once every 24 h on traplines, but preferably every 12 h, because one cannot know a priori whether traps will strike animals in appropriate locations for a quick kill. However, when using trapping devices such as killing neck snares that are legal and allowed by government agencies despite being inhumane, trappers should check them every 12 h. When traplines are situated near urban areas, e.g., within 10 km, checks should be done every 12 h to release pets and non-target animals.

Publication reform to safeguard wildlife from researcher harm.

Despite abundant focus on responsible care of laboratory animals, we argue that inattention to the maltreatment of wildlife constitutes an ethical blind spot in contemporary animal research. We begin by reviewing significant shortcomings in legal and institutional oversight, arguing for the relatively rapid and transformational potential of editorial oversight at journals in preventing harm to vertebrates studied in the field and outside the direct supervision of institutions. Straightforward changes to animal care policies in journals, which our analysis of 206 journals suggests are either absent (34%), weak, incoherent, or neglected by researchers, could provide a practical, effective, and rapidly imposed safeguard against unnecessary suffering. The Animals in Research: Reporting On Wildlife (ARROW) guidelines we propose here, coupled with strong enforcement, could result in significant changes to how animals involved in wildlife research are treated. The research process would also benefit. Sound science requires animal subjects to be physically, physiologically, and behaviorally unharmed. Accordingly, publication of methods that contravenes animal welfare principles risks perpetuating inhumane approaches and bad science.

Steel-Jawed Leghold Traps and Killing Neck Snares: Similar Injuries Command Change to Agreement on International Humane Trapping Standards.

According to the Agreement on International Humane Trapping Standards (AIHTS), which was signed by the European Community, Canada, and Russia in 1997, killing devices used for the capture of canids and other fur-bearing nonhuman animals should render an animal irreversibly unconscious within 300 s. However, killing neck snares are not included in the agreement. In this commentary, a parallel is drawn between injuries caused by steel-jawed leghold traps, which have been banned by the AIHTS signatory countries, and killing neck snares to demonstrate that these snares should also be included in international humane trapping standards (i.e., AIHTS). Previous scientific investigations have shown that neither manual nor power-killing neck snares can consistently render canids unconscious rapidly. Animals caught in killing neck snares suffer injuries that are similar to or worse than those reported for leg-captured canids. The authors strongly recommend that AIHTS be modified to include killing neck snares and that such devices be subject to the criteria applied to other trapping devices. Alternative restraining trapping devices, which are effective and more humane, are available for capturing wild canids.

Fencing Large Predator-Free and Competitor-Free Landscapes for the Recovery of Woodland Caribou in Western Alberta: An Ineffective Conservation Option.

n/a.

Predator Bounties in Western Canada Cause Animal Suffering and CompromiseWildlife Conservation Efforts.

Although predation bounty programs (rewards offered for capturing or killing an animal) ended more than 40 years ago in Canada, they were reintroduced in Alberta in 2007 by hunting, trapping, and farming organizations, municipalities and counties, and in 2009 in Saskatchewan, by municipal and provincial governments and the Saskatchewan Cattlemen's Association. Bounty hunters use inhumane and non-selective killing methods such as shooting animals in non-vital regions, and killing neck snares and strychnine poisoning, which cause suffering and delayed deaths. They are unselective, and kill many non-target species, some of them at risk. Predator bounty programs have been found to be ineffective by wildlife professionals, and they use killing methods that cause needless suffering and jeopardize wildlife conservation programs. Our analysis therefore indicates that government agencies should not permit the implementation of bounty programs. Accordingly, they must develop conservation programs that will minimize wildlife-human conflicts, prevent the unnecessary and inhumane killing of animals, and ensure the persistence of all wildlife species.

Relative abundance of American badger (Taxidea taxus) and red fox (Vulpes vulpes) in landscapes with high and low rodenticide poisoning levels.

Over the past decade, extensive poisoning campaigns have been conducted in southern Saskatchewan to control Richardson's ground squirrel Spermophilus richardsonii (Sabine, 1822) populations. Such campaigns might impact on predator abundance by decreasing prey levels, and also through secondary poisoning. Using spotlighting, we investigated the relative abundance of American badgers Taxidea taxus (Schreber, 1777) and red fox Vulpes vulpes (Linnaeus, 1758) in 2 study areas with road access and crops, but with different levels of poisoning. In the study area with relatively low poisoning (19.6% of the area traversed by roads), there were 2.2 times more American badgers per km of road and 6.4 times more red foxes per km than in the study area with high poisoning (89.7% of the area). It is recommended that an Integrated Pest Management program be developed to conserve natural predators across landscapes.

Trapping and marking terrestrial mammals for research: integrating ethics, performance criteria, techniques, and common sense.

We propose that researchers integrate ethics, performance criteria, techniques, and common sense when developing research trapping programs and in which members of institutional animal care and use committees address these topics when evaluating research protocols. To ask questions about ethics is in the best tradition of science, and researchers must be familiar with codes of ethics and guidelines for research published by professional societies. Researchers should always work to improve research methods and to decrease the effects on research animals, if for no other reason than to minimize the chances that the methods influence the animals' behavior in ways that affect research results. Traps used in research should meet performance criteria that address state-of-the-art trapping technology and that optimize animal welfare conditions within the context of the research. The proposal includes the following criteria for traps used in research: As Criterion I, killing-traps should render >/= 70% of animals caught irreversibly unconscious in /= 70% of animals with