Searching for Animal Sentience: A Systematic Review of the Scientific Literature

The Royal Zoological Society of Scotland's Approach to Assessing and Promoting Animal Welfare in Collaboration with Universities

Good zoos have four aims-to conserve species, educate the public, engage in research, and provide recreation-all of which can only be achieved when underpinned by high animal welfare standards. In this paper, we share the approach that The Royal Zoological Society of Scotland's (RZSS) Edinburgh Zoo and Highland Wildlife Park take to animal welfare. We highlight the role that animal welfare research, in collaboration with universities, has had in enabling the zoo to take an evidence-based approach to welfare and to put findings into practice. We share the collaborative process through which we developed and piloted the current animal welfare assessment tools, how they were validated, and how they were tested for reliability as part of a long-term collaboration between the Royal Zoological Society of Scotland and the University of Stirling: (1) the RZSS Welfare Assessment Tool, a 50-question animal welfare assessment adapted from the British and Irish Association of Zoos and Aquariums (BIAZA) Toolkit; and (2) the Stirling Toolkit, a package of evidence-based resources for behavioural-data collection. Our aim is to facilitate standardised, evidence-based approaches to assessing animal welfare which, when finalised, can be used collaboratively across zoos.

Listen to Us: Perceptions of Animal Voice and Agency

In many contexts, the interests of nonhuman animals (hereafter "animals") are often overlooked or considered to be a lower priority than those of humans. While strong arguments exist for taking animal moral claims seriously, these largely go unheard due to dominant anthropocentric attitudes and beliefs. This study aimed to explore how animal interests might be best represented in the human world. We conducted interviews to investigate people's perceptions of what it means to speak for other animals and who can reliably represent animal interests. Using Grounded Theory analytical methods, we identified one major theme: "Animal voice", and its subthemes: "Animals do/do not have a voice", "Human language constructs realities and paradigms", and "Let animals speak". Our findings illustrate how human language constructs contribute to shaping the realities of animals by contextually defining them as voiceless. This has serious implications for animals, society, and the environment. Drawing parallels with the relevant literature, our results reflect calls for the social and political recognition of animal voice as fundamental to animal representation. We recommend future research to focus on developing ethical and compassionate approaches to understanding animal subjective experiences to empower and amplify animal voices.

Recognition of emotion and pain by owners benefits the welfare of donkeys in a challenging working environment

Working donkeys (Equus asinus) support human living standards globally. However, there is little information on the effect of human perceptions of emotion and pain on the welfare of working donkeys. We interviewed donkey owners (n = 332) in Pakistan to determine the relationship between human perspectives on donkey sentience: emotions and the ability to feel pain, and the routine working practices that could impact donkey welfare. The majority of donkey owners used padding under the saddle (n = 211; 63.6%; 95% CI (58.3%-68.9%)) and provided access to food (n = 213; 64.2%; 95% CI (58.9%-69.3%)) and water (n = 195; 58.7%; 95% CI (53.4%-64.1%)) during the working day. Owners reported that at some point in their donkey's life, 65.3% (95% CI (60.2%-70.5%)) had load-associated injuries, of which 27.7% (n = 92; 95% CI (22.8%-32.5%)) were wounds, 20.5% (n = 68; 95% CI (16.1%-24.8%)) were lameness and 7.2% (n = 24; 95% CI 4.4%-10.0%) were back pain. In total, 81.3% (95% CI 77.1%-85.5%; n = 270) of owners believed that their donkeys felt pain, and 70.2% (95% CI (65.2%-75.1%; n = 233) of owners believed that their donkeys had emotions. Multiple correspondence analysis (MCA) was used to understand the relationship between owners' recognition of emotions and pain in donkeys and their working practices. The MCA factor map revealed two clusters, named positive and negative clusters. The positive cluster included owner's recognition of donkey pain and emotions, the availability of food and water, use of padding under the saddle, absence of injuries along with the willingness to follow loading guidelines. The negative cluster represented practices that did not benefit donkey welfare, such as using saddles without padding and a lack of food and water during work. The presence of injuries, owners not recognizing that donkeys feel pain and emotion along with an unwillingness to follow loading guidelines were also found in the negative cluster. We show that the owners who recognized sentience in their donkeys were more likely to use practices that are good for donkey welfare. The ability of owners to identify sentience in donkeys, along with their willingness to follow welfare guidelines, are important factors in improving the lives of working donkeys.

Conditioned Place Avoidance in the Planaria Schmidtea mediterranea: A Pre-clinical Invertebrate Model of Anxiety-Related Disorders

The objective of the present study was to develop a model of avoidance learning and its extinction in planarians (Schmidtea mediterranea). Based on previous experiments showing conditioned place preference, we developed a procedure to investigate conditioned place avoidance (CPA) using shock as an unconditioned stimulus (US) and an automated tracking system to record the animals' behaviour. In Experiment 1, we assessed the unconditioned properties of different shock intensities by measuring post shock activity. In two subsequent experiments we investigated CPA using different designs, surfaces as conditioned stimuli (CSs; rough and smooth), and different US intensities (5V and 10V). In general, we observed the successful development of CPA. However, CPA was stronger with higher shock intensities, and we found that, in our preparation, a rough surface is best at entering into an association with the shock than a smooth surface. Finally, we also observed extinction of CPA. The evidence of CPA and its extinction in flatworms validates the planaria as a pre-clinical model for the study of avoidance learning, a hallmark of anxiety disorders.

The sentience shift in animal research

One of the primary concerns in animal research is ensuring the welfare of laboratory animals. Modern views on animal welfare emphasize the role of animal sentience, i.e. the capacity to experience subjective states such as pleasure or suffering, as a central component of welfare. The increasing official recognition of animal sentience has had large effects on laboratory animal research. The Cambridge Declaration on Consciousness (Low et al., University of Cambridge, 2012) marked an official scientific recognition of the presence of sentience in mammals, birds, and cephalopods. Animal sentience has furthermore been recognized in legislation in the European Union, UK, New Zealand and parts of Australia, with discussions underway in other parts of the world to follow suit. In this paper, we analyze this shift towards recognition of sentience in the regulation and practice in the treatment of laboratory animals and its effects on animal welfare and use.

Alternative Paradigms in Animal Health Decisions: A Framework for Treating Animals Not Only as Commodities

Simple Summary

Since zoonotic diseases can be transmitted from animals to humans, more comprehensive measures are needed when preventing and controlling these diseases. Because the value of animals is mainly based on monetary terms, animals are typically treated as commodities, impacting public health decisions. Therefore, a framework is proposed to value the health of animals beyond money for public health decision-making with a “One Health” approach. The aim is to have more comprehensive animal values based on the opinion of societies. However, tackling the dilemmas related to animal diseases, public health, and welfare still represents a challenge and a work in progress.

Abstract

Zoonoses are diseases transmitted from (vertebrate) animals to humans in the environment. The control and prevention of these diseases require an appropriate way to measure health value for prudent and well-balanced decisions in public health, production costs, and market values. Currently, the impact of diseases and animal disease control measures are typically assessed in monetary values, thus lacking consideration of other values such as emotional, societal, ecological, among others. Therefore, a framework is proposed that aims to explore, understand, and open up a conversation about the non-monetary value of animals through environmental and normative ethics. This method might help us complement the existing metrics in health, which are currently DALY and zDALY, adding more comprehensive values for animal and human health to the “One Health” approach. As an example of this framework application, participants can choose what they are willing to give in exchange for curing an animal in hypothetical scenarios selecting a human health condition to suffer, the amount of money, and lifetime as a tradeoff. Considering animals beyond their monetary value in public health decisions might contribute to a more rigorous assessment of the burden of zoonotic diseases, among other health decisions. This study is structured as follows: after a brief introduction of zoonoses, animal health, and health metrics, briefly, different environmental health perspectives are presented. Based on this, a framework for animal health decisions is proposed. This framework introduces the “anthropozoocentric interface” based on anthropocentrism and zoocentrism perspectives.

Cognitive bias in animal behavior science: a philosophical perspective

Emotional states of animals influence their cognitive processes as well as their behavior. Assessing emotional states is important for animal welfare science as well as for many fields of neuroscience, behavior science, and biomedicine. This can be done in different ways, e.g. through assessing animals’ physiological states or interpreting their behaviors. This paper focuses on the so-called cognitive judgment bias test, which has gained special attention in the last 2 decades and has become a highly important tool for measuring emotional states in non-human animals. However, less attention has been given to the epistemology of the cognitive judgment bias test and to disentangling the relevance of different steps in the underlying cognitive mechanisms. This paper sheds some light on both the epistemology of the methods and the architecture of the underlying cognitive abilities of the tested animals. Based on this reconstruction, we propose a scheme for classifying and assessing different cognitive abilities involved in cognitive judgment bias tests.

A Kettle of Fish: A Review of the Scientific Literature for Evidence of Fish Sentience

Fish are traded, caught, farmed, and killed in their trillions every year around the world, yet their welfare is often neglected and their sentience regularly disregarded. In this review, we have sought to (1) catalogue the extent to which fish sentience has featured over the past 31 years in the scientific literature and (2) discuss the importance of fish sentience in relation to their commercial uses. We searched the journal database Science Direct using 42 keywords that describe traits or elements of sentience to find articles that were referring to or exploring fish sentience. Our review returned 470 results for fish sentience in 142 different species and subspecies of fish, and featured 19 different sentience keywords. The top four keywords were; 'stress' (psychological) (n = 216, 45.9% of total results), 'anxiety' (n = 144, 30.6%), 'fear' (n = 46, 9.7%), and 'pain' (n = 27, 5.7%). Our findings highlight an abundance of evidence for fish sentience in the published scientific literature. We conclude that legislation governing the treatment of fish and attitudes towards their welfare require scrutiny so that their welfare can be safeguarded across the globe.

Sentience Matters: Analysing the Regulation of Calf-Roping in Australian Rodeos

Simple Summary

The rodeo event of calf-roping, also known as the ‘rope and tie’, involves a contestant on horseback chasing, lassoing, catching, restraining, lifting and forcing a calf to the ground before tying the calf’s legs. The calves used in the event are handled in a manner that is likely to elicit fear and distress, and cause physical pain. In Australia, animal welfare legislation operates to prevent or constrain people from causing pain or distress to animals because animals are sentient beings. In this commentary, we discuss the research establishing that calves are sentient and explore the welfare concerns associated with calf-roping. We conclude that the concerns are such as to warrant protection under animal welfare legislation. The regulation of calf-roping in Australia is then analysed to explore how calves used in the event are excluded from this protection. We suggest that the exclusion of calves used in calf-roping from certain legal protections may be inconsistent with the purpose of animal welfare legislation, and that the variation in protection for these calves and other animals with corresponding levels of sentience requires further attention.

Abstract

Animal sentience is recognised either implicitly or explicitly in legislation in all Australian states and territories. In these jurisdictions, animal welfare legislation prohibits acts of cruelty towards animals because animals have the capacity to experience pain or suffering. This acknowledgement is supported by scientific research that demonstrates animal sentience, as well as public opinion. Despite these legal prohibitions, calf-roping, a common event at rodeos, is permitted in the majority of Australian jurisdictions. In recent times, calf-roping has generated significant public concern due to the potential for injury, pain or distress for the calves involved. This concern is evidently shared in some overseas jurisdictions, such as New Zealand, where animal advocacy organisations have filed a legal challenge asserting that rodeo events violate New Zealand’s animal welfare legislation due to the pain and distress inflicted on the animals. This commentary discusses these welfare concerns, the legislative inconsistencies between Australian jurisdictions and the problematic legal status of calf-roping in Australia.

Becoming a Part of the Houyhnhnm’s Environment

R. Goto Collins and T. Collins are environmental artists. Their goal is to challenge their own subjectivity through research and practice. Reiko’s interest in relational and collaborative artwork with the more-than-human world goes back to the 1980s. In 2014, she decided to engage a horse (Darkness) as a collaborative partner, with Tim’s support. In this article, the reader will find a reflection on a creative inquiry between a horse, two humans and their shared environment. How a practice (of being with) might reveal an evolving subjectivity (becoming) with a horse? With a foundation of reading and practical testing of Edith Stein’s ideas in we then looked to Charles Sanders Pierce’s work on signs This would provide a structure that enabled us to appreciate and process the range of signs discovered as we sought to communicate across species. Specific questions include: does Darkness interact with and adapt to changes in his environment? Is he self-aware and evolving through life experience, uniquely engaged with his environment? By recognizing and supporting his life and intelligence, would he reveal a world Tim and I were immersed in but could not perceive? How could we communicate that world through arts-based research?

A critical review of the compassionate conservation debate

Compassionate conservation holds that compassion should transform conservation. It has prompted heated debate and has been criticized strongly. We reviewed the debate to characterize compassionate conservation and to philosophically analyze critiques that are recurring and that warrant further critical attention. The necessary elements of compassionate conservation relate to the moral value of sentient animals and conservation and to science and conservation practice. Although compassionate conservation has several nontraditional necessary conditions, it also importantly allows a degree of pluralism in values and scientific judgment regarding animals and conservation practice. We identified 52 specific criticisms from 11 articles that directly critique compassionate conservation. We closely examined 33 of these because they recurred regularly or included substantial questions that required further response. Critics criticized compassionate conservation's ethical foundations, scientific credentials, clarity of application, understanding of compassion, its alleged threat to conservation and biodiversity. Some criticisms, we found, are question begging, confused, or overlook conceptual complexity. These criticisms raise questions for critics and proponents, regarding, for example, equal versus differential intrinsic moral value of different sentient animals (including humans), problems of natural and human-caused suffering of wild animals and predation, and the acceptability of specific conservation practices within compassionate conservation. By addressing recurring and faulty critiques of compassionate conservation and identifying issues for compassionate conservation to address, this review provides a clearer basis for crucial ongoing interdisciplinary dialogue about ethics, values, and conservation.

A Perspective on Strategic Enrichment for Brain Development: Is This the Key to Animal Happiness?

Livestock animals are sentient beings with cognitive and emotional capacities and their brain development, similar to humans and other animal species, is affected by their surrounding environmental conditions. Current intensive production systems, through the restrictions of safely managing large numbers of animals, may not facilitate optimal neurological development which can contribute to negative affective states, abnormal behaviors, and reduce experiences of positive welfare states. Enrichment provision is likely necessary to enable animals to reach toward their neurological potential, optimizing their cognitive capacity and emotional intelligence, improving their ability to cope with stressors as well as experience positive affect. However, greater understanding of the neurological impacts of specific types of enrichment strategies is needed to ensure enrichment programs are effectively improving the individual's welfare. Enrichment programs during animal development that target key neurological pathways that may be most utilized by the individual within specific types of housing or management situations is proposed to result in the greatest positive impacts on animal welfare. Research within livestock animals is needed in this regard to ensure future deployment of enrichment for livestock animals is widespread and effective in enhancing their neurological capacities.

The Hitchhiker's Guide to Integration of Social and Ethical Awareness in Precision Livestock Farming Research

While fully automated livestock production may be considered the ultimate goal for optimising productivity at the farm level, the benefits and costs of such a development at the scale at which it needs to be implemented must also be considered from social and ethical perspectives. Automation resulting from Precision Livestock Farming (PLF) could alter fundamental views of human-animal interactions on farm and, even further, potentially compromise human and animal welfare and health if PLF development does not include a flexible, holistic strategy for integration. To investigate topic segregation, inclusion of socio-ethical aspects, and consideration of human-animal interactions within the PLF research field, the abstracts from 644 peer-reviewed publications were analysed using the recent advances in the Natural Language Processing (NLP). Two Latent Dirichlet Allocation (LDA) probabilistic models with varying number of topics (13 and 3 for Model 1 and Model 2, respectively) were implemented to create a generalised research topic overview. The visual representation of topics produced by LDA Model 1 and Model 2 revealed prominent similarities in the terms contributing to each topic, with only weight for each term being different. The majority of terms for both models were process-oriented, obscuring the inclusion of social and ethical angles in PLF publications. A subset of articles (5%, n = 32) was randomly selected for manual examination of the full text to evaluate whether abstract text and focus reflected that of the article as a whole. Few of these articles (12.5%, n = 4) focused specifically on broader ethical or societal considerations of PLF or (9.4%, n = 3) discussed PLF with respect to human-animal interactions. While there was consideration of the impact of PLF on animal welfare and farmers in nearly half of the full texts examined (46.9%, n = 15), this was often limited to a few statements in passing. Further, these statements were typically general rather than specific and presented PLF as beneficial to human users and animal recipients. To develop PLF that is in keeping with the ethical values and societal concerns of the public and consumers, projects, and publications that deliberately combine social context with technological processes and results are needed.

A Retrospective Literature Evaluation of the Integration of Stress Physiology Indices, Animal Welfare and Climate Change Assessment of Livestock

In this retrospective study, we conducted a desktop-based analysis of published literature using the ScienceDirect™ search engine to determine the proportion of livestock research within the last 7 years (2015-2021) that have applied animal welfare assessment combining objective measures of physiological stress and evaluation of climate change factors in order to provide an account of livestock productivity. From the search results, 563 published articles were reviewed. We found that the majority of the literature had discussed animal production outcomes (n = 491) and animal welfare (n = 453) either individually or in conjunction with another topic. The most popular occurrence was the combination of animal welfare assessment, objective measures of stress physiology and production outcomes discussed collectively (n = 218). We found that only 125 articles had discussed the impact of climate change (22.20%) on livestock production and/or vice versa. Furthermore, only 9.4% (n = 53) of articles had discussed all four factors and published research was skewed towards the dairy sector. Overall, this retrospective paper highlights that although research into animal welfare assessment, objective measures of stress and climate change has been applied across livestock production systems (monogastrics and ruminants), there remains a shortfall of investigation on how these key factors interact to influence livestock production. Furthermore, emerging technologies that can boost the quantitative evaluation of animal welfare are needed for both intensive and extensive production systems.

Animal Harms and Food Production: Informing Ethical Choices

Simple Summary

Consideration of animal welfare in food choices has become an influential contemporary theme. Traditional animal welfare views about food have been largely restricted to direct and intentional harms to livestock in intensive animal agriculture settings. However, many harms to animals arising from diverse food production practices in the world are exerted indirectly and unintentionally and often affect wildlife. Here we apply a qualitative analysis of food production by considering the breadth of harms caused by different food production systems to wild as well as domestic animals. Production systems are identified that produce relatively few and relatively many harms. The ethical implications of these findings are discussed for consumers concerned with the broad animal welfare impacts of their food choices.

Abstract

Ethical food choices have become an important societal theme in post-industrial countries. Many consumers are particularly interested in the animal welfare implications of the various foods they may choose to consume. However, concepts in animal welfare are rapidly evolving towards consideration of all animals (including wildlife) in contemporary approaches such as “One Welfare”. This approach requires recognition that negative impacts (harms) may be intentional and obvious (e.g., slaughter of livestock) but also include the under-appreciated indirect or unintentional harms that often impact wildlife (e.g., land clearing). This is especially true in the Anthropocene, where impacts on non-human life are almost ubiquitous across all human activities. We applied the “harms” model of animal welfare assessment to several common food production systems and provide a framework for assessing the breadth (not intensity) of harms imposed. We considered all harms caused to wild as well as domestic animals, both direct effects and indirect effects. We described 21 forms of harm and considered how they applied to 16 forms of food production. Our analysis suggests that all food production systems harm animals to some degree and that the majority of these harms affect wildlife, not livestock. We conclude that the food production systems likely to impose the greatest overall breadth of harms to animals are intensive animal agriculture industries (e.g., dairy) that rely on a secondary food production system (e.g., cropping), while harvesting of locally available wild plants, mushrooms or seaweed is likely to impose the least harms. We present this conceptual analysis as a resource for those who want to begin considering the complex animal welfare trade-offs involved in their food choices.

Reviewing the Review: A Pilot Study of the Ethical Review Process of Animal Research in Sweden

The use of animals in research entails a range of societal and ethical issues, and there is widespread consensus that animals are to be kept safe from unnecessary suffering. Therefore, harm done to animals in the name of research has to be carefully regulated and undergo ethical review for approval. Since 2013, this has been enforced within the European Union through Directive 2010/63/EU on the protection of animals used for scientific purposes. However, critics argue that the directive and its implementation by member states do not properly consider all aspects of animal welfare, which risks causing unnecessary animal suffering and decreased public trust in the system. In this pilot study, the ethical review process in Sweden was investigated to determine whether or not the system is in fact flawed, and if so, what may be the underlying cause of this. Through in-depth analysis of 18 applications and decisions of ethical reviews, we found that there are recurring problems within the ethical review process in Sweden. Discrepancies between demands set by legislation and the structure of the application form lead to submitted information being incomplete by design. In turn, this prevents the Animal Ethics Committees from being able to fulfill their task of performing a harm-benefit analysis and ensuring Replacement, Reduction, and Refinement (the 3Rs). Results further showed that a significant number of applications failed to meet legal requirements regarding content. Similarly, no Animal Ethics Committee decision contained any account of evaluation of the 3Rs and a majority failed to include harm-benefit analysis as required by law. Hence, the welfare may be at risk, as well as the fulfilling of the legal requirement of only approving "necessary suffering". We argue that the results show an unacceptably low level of compliance in the investigated applications with the legal requirement of performing both a harm-benefit analysis and applying the 3Rs within the decision-making process, and that by implication, public insight through transparency is not achieved in these cases. In order to improve the ethical review, the process needs to be restructured, and the legal demands put on both the applicants and the Animal Ethics Committees as such need to be made clear. We further propose a number of improvements, including a revision of the application form. We also encourage future research to further investigate and address issues unearthed by this pilot study.

The neuroscience of positive emotions and affect: Implications for cultivating happiness and wellbeing

This review paper provides an integrative account regarding neurophysiological correlates of positive emotions and affect that cumulatively contribute to the scaffolding for happiness and wellbeing in humans and other animals. This paper reviews the associations among neurotransmitters, hormones, brain networks, and cognitive functions in the context of positive emotions and affect. Consideration of lifespan developmental perspectives are incorporated, and we also examine the impact of healthy social relationships and environmental contexts on the modulation of positive emotions and affect. The neurophysiological processes that implement positive emotions are dynamic and modifiable, and meditative practices as well as flow states that change patterns of brain function and ultimately support wellbeing are also discussed. This review is part of "The Human Affectome Project" (http://neuroqualia.org/background.php), and in order to advance a primary aim of the Human Affectome Project, we also reviewed relevant linguistic dimensions and terminology that characterizes positive emotions and wellbeing. These linguistic dimensions are discussed within the context of the neuroscience literature with the overarching goal of generating novel recommendations for advancing neuroscience research on positive emotions and wellbeing.

Assessing the Uniformity in Australian Animal Protection Law: A Statutory Comparison

Animal welfare is not included in the Australian Constitution, rendering it a residual power of the states and territories. Commentators have suggested that inconsistencies exist between the state and territory statutes, and that a uniform approach would be beneficial. However, there has been no comprehensive assessment of the nature or extent of these purported inconsistencies. This review addresses this gap by providing a state-by-state comparison of animal protection statutes based on key provisions. Utilizing systematic review methodology, every current Australian statute with an enforceable protection provision relating to animal welfare was identified. A total of 436 statutes were examined, with 42 statutes being included in the detailed analysis. The comparison showed that animal protection laws are generally consistent between each Australian jurisdiction and were found to have similar shortcomings, notably including lack of a consistent definition of 'animal' and reliance on forms of legal punishment to promote animal welfare which have questionable effectiveness. It is argued that there is a need for attention to definitions of key terms and future consideration of alternative forms of penalties, but that a uniform federal approach may not be necessary to address these shortcomings.

Computational animal welfare: towards cognitive architecture models of animal sentience, emotion and wellbeing

To understand animal wellbeing, we need to consider subjective phenomena and sentience. This is challenging, since these properties are private and cannot be observed directly. Certain motivations, emotions and related internal states can be inferred in animals through experiments that involve choice, learning, generalization and decision-making. Yet, even though there is significant progress in elucidating the neurobiology of human consciousness, animal consciousness is still a mystery. We propose that computational animal welfare science emerges at the intersection of animal behaviour, welfare and computational cognition. By using ideas from cognitive science, we develop a functional and generic definition of subjective phenomena as any process or state of the organism that exists from the first-person perspective and cannot be isolated from the animal subject. We then outline a general cognitive architecture to model simple forms of subjective processes and sentience. This includes evolutionary adaptation which contains top-down attention modulation, predictive processing and subjective simulation by re-entrant (recursive) computations. Thereafter, we show how this approach uses major characteristics of the subjective experience: elementary self-awareness, global workspace and qualia with unity and continuity. This provides a formal framework for process-based modelling of animal needs, subjective states, sentience and wellbeing.

The brain: a concept in flux

One of the most important aspects of the scientific endeavour is the definition of specific concepts as precisely as possible. However, it is also important not to lose sight of two facts: (i) we divide the study of nature into manageable parts in order to better understand it owing to our limited cognitive capacities and (ii) definitions are inherently arbitrary and heavily influenced by cultural norms, language, the current political climate, and even personal preferences, among many other factors. As a consequence of these facts, clear-cut definitions, despite their evident importance, are oftentimes quite difficult to formulate. One of the most illustrative examples about the difficulty of articulating precise scientific definitions is trying to define the concept of a brain. Even though the current thinking about the brain is beginning to take into account a variety of organisms, a vertebrocentric bias still tends to dominate the scientific discourse about this concept. Here I will briefly explore the evolution of our 'thoughts about the brain', highlighting the difficulty of constructing a universally (or even a generally) accepted formal definition of it and using planarians as one of the earliest examples of organisms proposed to possess a 'traditional', vertebrate-style brain. I also suggest that the time is right to attempt to expand our view of what a brain is, going beyond exclusively structural and taxa-specific criteria. Thus, I propose a classification that could represent a starting point in an effort to expand our current definitions of the brain, hopefully to help initiate conversations leading to changes of perspective on how we think about this concept. This article is part of the theme issue 'Liquid brains, solid brains: How distributed cognitive architectures process information'.

Causation, Responsibility, and Harm: How the Discursive Shift from Law and Ethics to Social Justice Sealed the Plight of Nonhuman Animals

Moral and political philosophers no longer condemn harm inflicted on nonhuman animals as self-evidently as they did when animal welfare and animal rights advocacy was at the forefront in the 1980s, and sentience, suffering, species-typical behavior, and personhood were the basic concepts of the discussion. The article shows this by comparing the determination with which societies seek responsibility for human harm to the relative indifference with which law and morality react to nonhuman harm. When harm is inflicted on humans, policies concerning negligence and duty of care and principles such as the 'but for' rule and the doctrine of double effect are easily introduced. When harm is inflicted on nonhumans, this does not happen, at least not any more. As an explanation for the changed situation, the article offers a shift in discussion and its basic terminology. Simple ethical considerations supported the case for nonhuman animals, but many philosophers moved on to debate different views on political justice instead. This allowed the creation of many conflicting views that are justifiable on their own presuppositions. In the absence of a shared foundation, this fragments the discussion, focuses it on humans, and ignores or marginalizes nonhuman animals.

Blind Trading: A Literature Review of Research Addressing the Welfare of Ball Pythons in the Exotic Pet Trade

Simple Summary

The Ball python is a small species that is commonly kept as an exotic pet across the world. Despite huge numbers of these snakes being kept and traded in the pet industry, there is very little information available about how catching, breeding, transporting and housing them in captivity could impact their welfare. Our study reviewed the published literature for this species and found 88 relevant peer-reviewed scientific papers. Physical health was the predominant focus of research, with numerous studies reporting on disease, injury or clinical treatments. Far fewer papers focused on other aspects of Ball python wellbeing, including behaviour, nutrition, environment or mental condition. We also found that very few studies focused on wellbeing prior to pet ownership, i.e., during the early stages of the trade chain when they are caught from the wild, transported, or bred in captivity. We recommend that more research is needed to assess the impact of the exotic pet trade on this species’ welfare. In particular, research on welfare conditions during capture and transportation of wild Ball pythons, and the potential effects of captive breeding, could help reduce suffering throughout the trade.

Abstract

Extensive numbers of Ball pythons are caught, bred, traded and subsequently kept in captivity across the world as part of the exotic pet industry. Despite their widespread availability as pets, relatively little is known about the potential welfare challenges affecting them. We reviewed the literature for research focused on the health and welfare of Ball pythons in the international pet trade. From a total of 88 articles returned from the search criteria, our analysis showed that very few actually focused on trade (10%) or animal welfare (17%). Instead, the majority (64%) of articles focused on veterinary science. There was a considerable bias towards physical health, with most studies neglecting the four other domains of animal welfare (behaviour, nutrition, environment and mental health). Furthermore, very few studies considered Ball pythons prior to resulting pet ownership, during wild capture and transportation or captive breeding operations. Our review demonstrates that our current understanding of welfare for Ball pythons traded as exotic pets is limited. We recommend that future research should focus on aspects of the industry that are currently overlooked, including the potential consequences of genetic selection during captive-breeding and the conditions provided for snakes prior to and during international transportation.

Given the Cold Shoulder: A Review of the Scientific Literature for Evidence of Reptile Sentience

Simple Summary

Reptiles are popular pets around the world, although their welfare requirements in captivity are not always met, due in part to an apparent lack of awareness of their needs. Herein, we searched a selection of the scientific literature for evidence of, and explorations into, reptile sentience. We used these findings to highlight: (1) how reptiles are recognised as being capable of a range of feelings; (2) what implications this has for the pet trade; and (3) what future research is needed to help maximise their captive welfare. We found 37 studies that assumed reptiles to be capable of the following emotions and states; anxiety, stress, distress, excitement, fear, frustration, pain, and suffering. We also found four articles that explored and found evidence for the capacity of reptiles to feel pleasure, emotion, and anxiety. These findings have direct implications for how reptiles are treated in captivity, as a better understanding of their sentience is critical in providing them with the best quality of life possible.

Abstract

We searched a selection of the scientific literature to document evidence for, and explorations into reptile sentience. The intention of this review was to highlight; (1) to what extent reptile capability for emotions have been documented in the scientific literature; (2) to discuss the implications this evidence has for the trade in reptiles; and (3) to outline what future research is needed to maximise their captive welfare needs. We used 168 keywords associated with sentience, to search through four journal databases and one open-access journal. We recorded studies that explored sentience in reptiles and those that recognised reptile sentience in their experiments. We found that reptiles were assumed to be capable of the following emotions and states; anxiety, distress, excitement, fear, frustration, pain, stress, and suffering, in 37 articles. We also found four articles that explored and found evidence for the capacity of reptiles to feel pleasure, emotion, and anxiety. These findings show that reptiles are considered to be capable of experiencing a range of emotions and states. This has implications for how reptiles are treated in captivity, as a better understanding could help to inform a range of different operational initiatives aimed at reducing negative animal welfare impacts, including improved husbandry and consumer behaviour change programmes.

Chattel or Child: The Liminal Status of Companion Animals in Society and Law

Companion animals in the U.S. are increasingly regarded as members of the family with whom one may share a strong emotional bond. However, despite an evolving social construction that has elevated their status in the dominant culture, companion animals lack meaningful legal rights, and “family member” is a provisional status that can be dissolved at will based on the discretion of the sole rights-holder in the relationship: the human owner. Because they are still defined within the U.S. legal system as property, it is a common lament within the animal protection movement that the law has not kept pace with the emergent cultural perception of companion animals as family or best friends who may occupy a significant place in one’s constellation of interpersonal relationships. But how divergent are the laws that govern our treatment of companion animals from prevailing social norms? This article examines current trends in animal law and society to shed light on this question. I find that while a new family member cultural status is emerging for companion animals in the U.S., their legal status as property is a countervailing force, enabling contradictory practices and beliefs that construct animals as expendable. The fact that their cultural status is in flux in turn reinforces their status under the law. I conclude with proposed policy reforms that will facilitate the integration of companion animals into society as true rather than rhetorical family members.

Demographics Regarding Belief in Non-Human Animal Sentience and Emotional Empathy with Animals: A Pilot Study among Attendees of an Animal Welfare Symposium

Simple Summary

Attitudes towards the welfare of non-human animals are related to beliefs about animals’ capabilities, particularly regarding experiences of pain and suffering. The current study explores the attitudes to animals among people who attended an animal welfare symposium at the University of Sydney. This population represents a unique sample of people who work, study or have a strong interest in animal care and welfare. The pilot study used a validated questionnaire that assessed attitudes to animals; specifically exploring participants’ (n = 41) beliefs about the sentience of animals and their emotional empathy with animals. The results found significant associations between participants’ beliefs in animal sentience and their demographic variables (age, sex and occupation). Female attendees showed stronger belief in sentience than male attendees did. When looking at emotional empathy with animals, the participants’ responses to the statements assigned into three clusters (or distinct groups) based on their content which reflected the internal emotional lives of animals and the treatment of animals by humans (Cluster 1), human interactions with animals (Cluster 2) and the keeping of companion and zoo animals (Cluster 3).

Abstract

Attitudes to animals are linked to beliefs about their ability to experience pain and suffering, their cognition, and their sentience. Education and awareness-raising play a pivotal role in increasing society’s consideration of non-human animal welfare. The current pilot study explores the attitudes towards animal welfare among a unique population of people who attended an animal welfare symposium at the University of Sydney. It involved administration of a validated questionnaire that assessed attitudes to animals; specifically exploring participants’ (n = 41) beliefs about the sentience of animals and their emotional empathy with animals. The resultant data revealed significant associations between participants’ beliefs in animal sentience and their demographic variables (age, sex and occupation). Female attendees showed stronger beliefs in sentience than male attendees did. Concerning sentience in cows, pigs and cats, older attendees showed stronger beliefs than younger people in sentience relating to hunger and pain. Also, with regard to questions about sentience in dogs, older attendees showed stronger beliefs than younger people in pain-related sentience in dogs. When exploring emotional empathy with animals, the participants’ statements could be assigned to three clusters characterised by the internal emotional lives of animals and the treatment of animals by humans (Cluster 1), human interactions with animals (Cluster 2) and the keeping of companion and zoo animals (Cluster 3). To the authors’ knowledge, this pilot study is the first of its kind to investigate the attitudes towards animal welfare of an important group of people who work, study or have a special interest within the animal care and welfare domain.

Vocal expression of emotional valence in Przewalski's horses (Equus przewalskii)

Vocal expression of emotions has been suggested to be conserved throughout evolution. However, since vocal indicators of emotions have never been compared between closely related species using similar methods, it remains unclear whether this is the case. Here, we investigated vocal indicators of emotional valence (negative versus positive) in Przewalski’s horses, in order to find out if expression of valence is similar between species and notably among Equidae through a comparison with previous results obtained in domestic horse whinnies. We observed Przewalski’s horses in naturally occurring contexts characterised by positive or negative valence. As emotional arousal (bodily activation) can act as a confounding factor in the search for indicators of valence, we controlled for its effect on vocal parameters using a behavioural indicator (movement). We found that positive and negative situations were associated with specific types of calls. Additionally, the acoustic structure of calls differed according to the valence. There were some similarities but also striking differences in expression of valence between Przewalski’s and domestic horses, suggesting that vocal expression of emotional valence, unlike emotional arousal, could be species specific rather than conserved throughout evolution.

What We Know about the Public's Level of Concern for Farm Animal Welfare in Food Production in Developed Countries

Population growth and rising consumption of meat, dairy, eggs and fish are forcing the world to face the intersecting challenges of how to sustainably feed a population expected to exceed 9 billion by 2050, while also controlling the impact of food production on the planet, on people and on animals. This review acknowledges the absence of a globally accepted definition of animal welfare and then explores the literature regarding different levels of concern for animal welfare in food production by such stakeholders as veterinarians, farmers, and the general public. It focuses on the evidence that the general public's level of concern for animal welfare is linked to various demographic and personal characteristics, such as age, gender, religion, location, meat eating, and knowledge of animal welfare. Certain animals have characteristics that influence concern for their welfare, with those species that are considered more intelligent being afforded more concern. There is compelling evidence that the general public's understanding of animal welfare in food production is poor. Acknowledging that public concern can be a driving force to change current production methods, the authors suggest widespread consciousness raising to redefine socially acceptable methods of food production from animals and to ensure that it remains in step with societal concerns.

Life and consciousness - The Vedāntic view

In the past, philosophers, scientists, and even the general opinion, had no problem in accepting the existence of consciousness in the same way as the existence of the physical world. After the advent of Newtonian mechanics, science embraced a complete materialistic conception about reality. Scientists started proposing hypotheses like abiogenesis (origin of first life from accumulation of atoms and molecules) and the Big Bang theory (the explosion theory for explaining the origin of universe). How the universe came to be what it is now is a key philosophical question. The hypothesis that it came from Nothing (as proposed by Stephen Hawking, among others), proves to be dissembling, since the quantum vacuum can hardly be considered a void. In modern science, it is generally assumed that matter existed before the universe came to be. Modern science hypothesizes that the manifestation of life on Earth is nothing but a mere increment in the complexity of matter — and hence is an outcome of evolution of matter (chemical evolution) following the Big Bang. After the manifestation of life, modern science believed that chemical evolution transformed itself into biological evolution, which then had caused the entire biodiversity on our planet. The ontological view of the organism as a complex machine presumes life as just a chance occurrence, without any inner purpose. This approach in science leaves no room for the subjective aspect of consciousness in its attempt to know the world as the relationships among forces, atoms, and molecules. On the other hand, the Vedāntic view states that the origin of everything material and nonmaterial is sentient and absolute (unconditioned). Thus, sentient life is primitive and reproductive of itself – omne vivum ex vivo – life comes from life. This is the scientifically verified law of experience. Life is essentially cognitive and conscious. And, consciousness, which is fundamental, manifests itself in the gradational forms of all sentient and insentient nature. In contrast to the idea of objective evolution of bodies, as envisioned by Darwin and followers, Vedānta advocates the idea of subjective evolution of consciousness as the developing principle of the world. In this paper, an attempt has been made to highlight a few relevant developments supporting a sentient view of life in scientific research, which has caused a paradigm shift in our understanding of life and its origin.

Nasal temperatures in dairy cows are influenced by positive emotional state

Understanding how animals express positive emotions is an important area of focus for animal welfare science, yet it is widely neglected. Emotions can be either positive or negative in valence, depending on the rewarding or punishing nature of the stimulus, and they can vary in the degree of arousal or excitement. Previous literature has shown a strong connection between peripheral temperatures and high arousal, negative experiences. Stress, fear and frustration have all been found to cause a drop in peripheral temperature. Little is known however, about whether the experience of positive emotions affects peripheral temperatures. In this study we sought to identify whether the nasal temperature of cows was affected by emotions, and if nasal temperature could be reliably used as a measure of emotional state in cows. We induced a positive, low arousal emotional state by stroking cows in preferred regions, in a similar manner to allogrooming. We performed 350 full focal observations, each comprising three conditions; pre-stroking, stroking, and post-stroking. During each 15minute focal observation we remotely took the focal cow's nasal temperature six times, twice during each condition. We analysed the data using the one-way ANOVA repeated measures test and found a significant difference overall (F (2, 1.935)=9.372, p<0.01). Post-hoc pairwise comparisons indicated that the total mean nasal temperature decreased significantly during the stroking condition (25.91°C, SD=1.21), compared with both the pre-stroking (26.27°C, SD=1.01, p<0.01) and post-stroking conditions (26.44°C, SD=1.12, p<0.01). There was no significant difference between the pre-stroking and post-stroking conditions (p=0.14). We suggest that the cows were in a low state of arousal during the entire focal observation, as no other changes to the cows' environment had been made, and the cows were habituated to both the procedure and the researchers. Furthermore, the stroking stimulus is known to induce a state of relaxation and lower the heart rate of cows. This leads us to conclude that the drop in nasal temperature was indicative of the change in valence, rather than a change in arousal. These findings show that positive emotional state may have the same effect on the peripheral temperatures of mammals as a negative state does. This raises questions regarding the triggers for emotional fever, which is often considered to be associated only with negative states and high arousal. Our results indicate that nasal temperature in cows may prove to be a useful measure of a change in emotional state, but further research is required to validate these findings and to explore the effect of arousal on peripheral temperatures.