Heather Browning

There are many decision contexts in which we require accurate information on animal welfare, in ethics, management, and policy. Unfortunately, many of the methods currently used for estimating animal welfare in these contexts are subjective and unreliable, and thus unlikely to be accurate. In this paper, I look at how we might apply principled methods from animal welfare science to arrive at more accurate scores, which will then help us in making the best decisions for animals. I construct and apply a framework of desiderata for welfare measures, to assess the best of the currently available methods and argue that a combined use of both a whole-animal measure and a combination measurement framework for assessing welfare will give us the most accurate answers to guide our action.

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.

One of the most challenging questions surrounding subjective animal welfare is whether these states are measurable: that is, is subjective welfare an appropriately quantifiable target for scientific enquiry and ethical and deliberative calculation? The availability of several different types of measurement scale raises important questions regarding whether subjective experience has the right properties to be meaningfully represented on the types of scale required for different applications. This methodological question has so far received scant attention in the animal welfare literature. In this paper, I address this omission by examining the types of measurement scale we can reasonably expect to apply to animal welfare measurements, and which we will actually need for our applications. I argue that our different applications will require variously ordinal, interval, and ratio scales, and that we have sufficient reason to believe that subjective welfare is a target with the appropriate characteristics to justify the practice of representing it using each of these types of scales.

‘Sentience’ sometimes refers to the capacity for any type of subjective experience, and sometimes to the capacity to have subjective experiences with a positive or negative valence, such as pain or pleasure. We review recent controversies regarding sentience in fish and invertebrates and consider the deep methodological challenge posed by these cases. We then present two ways of responding to the challenge. In a policy-making context, precautionary thinking can help us treat animals appropriately despite continuing uncertainty about their sentience. In a scientific context, we can draw inspiration from the science of human consciousness to disentangle conscious and unconscious perception (especially vision) in animals. Developing better ways to disentangle conscious and unconscious affect is a key priority for future research.

One of the biggest problems in applications of animal welfare science is our ability to make comparisons between different individuals, particularly different species. Although welfare science provides methods for measuring the welfare of individual animals, there’s no established method for comparing measures between individuals. This problem occurs because of the underdetermination of the conclusions given the data, arising from two sources of variation that we cannot distinguish – variation in the underlying target variable (welfare experience) and in the relationship of measured indicators to the target. In this paper I describe the similarity assumptions that underlie our current applications of interspecies comparisons and examine in which cases they are justified, as well as describing alternative methods we may use when they are not. In the end, all our available options for making interspecies comparisons are imperfect, and we need to make explicit context-specific decisions about which will be best for the task at hand while acknowledging their potential limitations. Future developments in our understanding of the biology of sentience will help strengthen our methods of making welfare comparisons.

In modern zoos, enrichment programs have become a standard part of animal care routines. Although 'higher' primates usually receive complex enrichment programs, encompassing many types of enrichment, these are less common for prosimians. These animals often largely receive food-based enrichment, as was previously the case at Auckland Zoo, where the ring-tailed lemur enrichment schedule contained only three different items, all food-related. Lemurs tend to be considered less curious and quick to learn than other primates, as well as being less manually dextrous, and for these reasons can be overlooked for complex enrichment. However, they have strong sensory abilities, in particular an acute sense of smell (Sauther et al 1999). This paper describes an enrichment program designed for the lemurs at Auckland Zoo with the aim of stimulating all senses.

Sentience is the capacity to have feelings, such as feelings of pain, pleasure, hunger, thirst, warmth, joy, comfort and excitement. It is not simply the capacity to feel pain, but feelings of pain, distress or harm, broadly understood, have a special significance for animal welfare law. Drawing on over 300 scientific studies, we evaluate the evidence of sentience in two groups of invertebrate animals: the cephalopod molluscs or, for short, cephalopods (including octopods, squid and cuttlefish) and the decapod crustaceans or, for short, decapods (including crabs, lobsters and crayfish). We also evaluate the potential welfare implications of current commercial practices involving these animals.

The performance of natural behavior is commonly used as a criterion in the determination of animal welfare. This is still true, despite many authors having demonstrated that it is not a necessary component of welfare –some natural behaviors may decrease welfare, while some unnatural behaviors increase it. Here I analyze why this idea persists, and what effects it may have. I argue that the disagreement underlying this debate on natural behavior is not one about which conditions affect welfare, but a deeper conceptual disagreement about what the state of welfare actually consists of. Those advocating natural behavior typically take a “teleological” view of welfare, in which naturalness is fundamental to welfare, while opponents to the criterion usually take a “subjective” welfare concept, in which welfare consists of the subjective experience of life by the animal. I argue that as natural functioning is neither necessary nor sufficient for understanding welfare, we should move away from the natural behavior criterion to an alternative such as behavioral preferences or enjoyment. This will have effects in the way we understand and measure welfare, and particularly in how we provide for the welfare of animals in a captive setting.

The keeping of captive animals in zoos and aquariums has long been controversial. Many take freedom to be a crucial part of animal welfare and, on these grounds, criticise all forms of animal captivity as harmful to animal welfare, regardless of their provisions. Here, we analyse what it might mean for freedom to matter to welfare, distinguishing between the role of freedom as an intrinsic good, valued for its own sake and an instrumental good, its value arising from the increased ability to provide other important resources. Too often, this debate is conducted through trading intuitions about what matters for animals. We argue for the need for the collection of comparative welfare data about wild and captive animals in order to settle the issue. Discovering more about the links between freedom and animal welfare will then allow for more empirically informed ethical decisions regarding captive animals.

This paper addresses what we consider to be the most pressing challenge for the emerging science of consciousness: the measurement problem of consciousness. That is, by what methods can we determine the presence of and properties of consciousness? Most methods are currently developed through evaluation of the presence of consciousness in humans and here we argue that there are particular problems in application of these methods to nonhuman cases—what we call the indicator validity problem and the extrapolation problem. The first is a problem with the application of indicators developed using the differences between conscious and unconscious processing in humans to the identification of other conscious vs. nonconscious organisms or systems. The second is a problem in extrapolating any indicators developed in humans or other organisms to artificial systems. However, while pressing ethical concerns add urgency to the attribution of consciousness and its attendant moral status to nonhuman animals and intelligent machines, we cannot wait for certainty and we advocate the use of a precautionary principle to avoid causing unintentional harm. We also intend that the considerations and limitations discussed in this paper can be used to further analyze and refine the methods of consciousness science with the hope that one day we may be able to solve the measurement problem of consciousness.