Animal Flatmates: Deep into their minds

Animal Flatmates: Deep into their minds

Copyright 2016 Rachele Malavasi

Published by Rachele Malavasi at Smashwords Edition

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Table of Contents

Acknowledgements

Preface

CHAPTER ONE: Rara Avis (among the others): the intellectual abilities of the domestic chick - Cinzia Chiandetti

Front-page birds

CHAPTER TWO: Horses in the mirror - Pia Lucidi

Intelligent horses

CHAPTER THREE: A wild animal in our living room: evolutiona and peculiarities of the cat-human relationship - Isabella Merola & Rachele Malavasi

Home sweet home

CHAPTER FOUR: Small brains, smart brains: the case of fish - Maria Elena Miletto Petrazzini

Not everyone knows that…

CHAPTER FIVE: Cold-bloded minds: cognition in reptiles - Gionata Stancher

Reptile classification and evolution

CHAPTER SIX: Affiliative and cognitive processes in the dog (Canis familiaris) - Tiziano Travain & Paola Valsecchi

The special case of guide dogs

CHAPTER SEVEN: How fruit flies colonize the world - Elisabetta Versace

Recent spread of an invasive Drosophila species:D. suzukii

List of contributors

Figures and tables

Endnotes

Acknowledgements

We wish to thank Fondazione Giordano Emilio Ghirardi ONLUS - Villa Contarini (Italy), who founded the meeting ThinkAnimal - Il mondo visto dagli animali non umani (Piazzola sul Brenta, PD, 1 marzo 2014). Some of the speakers of the meeting authored some of the chapters of this volume, taking inspiration from the content of the meeting. A volume with the Proceedings of the meeting in Italian language is available through the Foundation. We also wish to thank Cinzia Chiadetti and Andrea Caputi for the help they provided in creating this ebook.

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Preface

Rachele Malavasi

SEE, School of Ethical Equitation and Study Center for Natural Horse Management, Localitá La Praduscella, 54013 Moncigoli di Fivizzano (MS)

In the last forty years, the interest towards the mental skills of non-human animals (from now on, animals), their cognitive abilities and, more broadly, their behavior, has grown. The Cultural Revolution began during the 70s, born from the tail of behaviorism and flourishing in the new cognitivist paradigm of Piaget and colleagues. Already in 1872, Charles Darwin had granted animals the ability to feel and express emotions in his book The Expression of the Emotions in Man and Animals; yet, it was only in 1971 that psychology made its debut into ethology, when Mason revealed the mental component of stress (Mason 1971). By addressing specifically research on monkeys, Mason proposed the psychological apparatus as the main activator of the pituitary-adrenal cortex axis, refusing the widespread idea that stress was triggered mostly by physiological reactions. According to his hypothesis, the mental representation of the stressful event would be more stressful than the event itself.

It was a breakthrough. Although Pavlov, Skinner, Thorndike and other behaviorists had already tested animals for their mental abilities (in particular, learning skills), they did it from a perspective that clearly avoided considering the investigation of mind. Their studies of associative learning suggested that simple mechanisms such as the direct association between a conditioned stimulus and an action could explain most of the apparently complex behaviors, excluding mentalist explanations. Konrad Lorenz, one of the fathers of ethology, similarly described behavior patterns as organs evolved to fulfil specific functions (Lorenz 1974).

In this framework, Mason’s hypothesis that animals were able to form mental representations of reality was the first step into the study of animals’ mental states. From there on, research into the mental skills of animals multiplied, covering a broad range of topics from short-term memory to individual recognition, social learning, and intentional communication. Because of this, and thanks to the growing demand of attention towards animal rights from activists and the broad public, findings are now integrated into European politics and local rules. The year 1977 marked a milestone in animals’ rights: the EU included a Protocol in the Treaty of Amsterdam declaring animals as 'sentient beings'; this was intended to introduce legal obligations for animal welfare. A sentient animal is motivated by the need to feel good and avoid pain (Webster 2005).

Now that we can rightfully use the expressions feeling good and suffering as related to animals, to what extent are we going to use them? Which animal species may be granted the ability to feel good and pain? In identifying animals that may be granted the ability to feel good and pain, most readers from the general public would point to non-human primates, because of their genetic closeness to humans, while others might choose elephants due to their ability to recognize themselves in a mirror. Many will agree on granting dogs the ability to feel pleasure and affection because, among other reasons, they are so plain in expressing their feelings to the point of establishing an attachment bond with the owner (see Chapter Six). Similarly, cats lived in our houses for millennia and even evolved the ability to elaborate their vocalization by including the vocal elements of baby’s cries that solicit human females to provide the desired treats (see Chapter Three).

Yet, in our city, block, building, or even in our apartment live many other visible (and invisible) species with incredible cognitive skills, single individuals that are motivated by the need to feel good and avoid pain as well. To avoid pain may be for example translated as to avoid thirst or hunger. So, fruit flies travel over 15 kilometers to find a water spot, and from taking-off to navigation and landing, sophisticate sensory-motor and cognitive abilities are needed (see Chapter Seven).

To feel good includes being able to express species-specific skills. Horses can travel up to 30km/day, and the functionality of their digestive system works at best in motion; they can recognize conspecifics and live in complex fission-fusion societies. Even so, many owners keep horses in boxes where their movements are deeply limited and their social life is reduced to a minimum (see Chapter Two). Similarly, iguanas, which may be present in domestic contexts as exotic pets, have a social life that includes peculiar forms of greeting, such as body and chin rubbing, tail wagging, head bobs, mutual tongue licking, and allogrooming (see Chapter Five). Keeping iguanas in isolation excludes the possibility for them to perform these displays and engage in affiliative interactions with peers.

Other animals scarcely considered for their intellectual skills, yet often present on our plates, are chickens. To avoid pain also means to have access to cures. When given the opportunity, chickens prefer to feed on food integrated with painkillers: this act of self-medication suggests that chickens do perceive their pain and act to alleviate it (see Chapter One).

Even fish, for which the ability to perceive pain is still debated, should have the right to feel good in terms of feeling safe: some fish species engage in cooperative behaviors where they swim together toward a potential predator to inspect its degree of dangerousness (see Chapter Four). Safety is in numbers!

The aim of this volume is to promote, through knowledge, the welfare of some of the species that live closest to humans: pets (here, in particular dogs, cats, and reptiles kept as exotic pets), animals exploited for their meat (chickens, fish), engaged in work or recreational activities with humans (horses), or living in our houses unknown to the tenants (fruit flies). Precisely for this reason, we choose to use a simple and accessible language: this volume may not only be of interest to academics but also to the broad public and associations for animal rights or safeguarding animal welfare. They would find in this volume an objective and accurate guide towards a deeper understanding of these species.

We provide here an overview of the cognitive skills and their ontogeny of dogs, cats, fish, chickens, horses, fruit flies, and reptiles, without demanding completeness but rather focusing on some peculiar skills or aspects of each one. All contributions included in this volume come from Italian researchers in support of the cultural excellence of this country.

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References

Darwin, Charles. 1872. The Expression of the Emotions in Man and Animals John Murray: London.

European Union. 1997. Treaty of Amsterdam amending the Treaty on European Union, the Treaties establishing the European Communities and certain related acts. European Communities, Office for Official Publications, Luxembourg.

Lorenz, Konrad. 1974. Analogy as a source of knowledge. American Association for the Advancement of Science.

Mason, John W. 1971. A re-evaluation of the concept of ‘non-specificity’ in stress theory. Journal of Psychiatric research, 8:323-333.

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Chapter One

Rara Avis (Among The Others): The Intellectual Abilities Of The Domestic Chicken

Cinzia Chiandetti

University of Trieste, Department of Life Sciences

Psychology Unit Gaetano Kanizsa, via L. Giorgieri 5, I-34127 Trieste, Italy

In the past, birds have long been mistreated by Neurosciences and Cognitive Sciences because they were thought to be only capable of instinctual responses. Yet, they are nowadays in the spotlight of comparative investigation, because accumulating behavioural observations testify that, both in laboratory and in natural environments, avian species possess abilities typical of superlatively intelligent creatures.

Birds are evolutionarily distant from human beings and different in several respects, but they still have intellectual capacities comparable to ours. Among the numerous species of birds, chickens have a poor reputation. They are usually referred to as bird brains, meaning annoyingly stupid creatures; however, this chapter will review their astonishing social and cognitive abilities, which make them able to navigate and reason about their surroundings. Hens, roosters, and their chicks will appear in a new light. It will be unveiled that chickens are a real example of rara avis. Among all the other bird species.

No bird brain

For a long time, birds’ behavior has been thought to be entirely guided by unlearned stereotypical responses. Although this view dominated even the academic scenario until recently, we know now that it is completely wrong. Two main reasons account for its persistence. The first reason is that, from the anatomical point of view, the brain of a bird is markedly different from that of a mammal. At the beginning of the past century, anatomists started applying innovative techniques in the coloration of nerve cells, even to birds’ brains (first devised by Nissl and Golgi).They found that birds lack a neocortex, which was believed to be essential for a high and flexible behavioral repertoire (Elliot-Smith 1901). Birds’ brain is composed of nuclei forming basal ganglia, which in mammals are responsible for instinctual behaviors and endocrine regulation. Such neural architecture led scientists to conclude that birds are incapable of sophisticated behaviour. This interpretation suffered from a resilient tendency to classify organisms, from the simplest to the most complex, which is the second reason explaining the prejudices on birds’ cognitive abilities. We intuitively arrange organisms on a linear ladder (Figure 1.1, leftmost) of increased complexity for both anatomy (from simple worms to complex monkeys) and intellectual capabilities (from the automatic reflexes of insects to the empathy shown by dogs). The ladder is traditionally rooted in the idea of the Scala Naturae, or the Great Chain of Being. By combining the concept of evolution and the ladder, as first proposed by the father of comparative neuroanatomy Edinger (1855-1918), evolution would have progressed from simple avian brains made by nuclei regulating instinctual responses, to brains of more evolved organisms such as monkeys and humans. By placing the cortex (a very refined structure) side by side to the nuclei, evolution would have culminated in the human cerebrum, which allows higher and more flexible behaviors than those shown by birds.

Such an idea has been gradually abandoned in favour of the correct interpretation of Darwin’s Tree of Life (Figure 1-1, rightmost). Evolution has shaped species-specific mechanisms, developed to deal with specific prob¬lems, for instance, the verbal language in our species or enhanced spatial skills in food-hoarding birds. But evolution has also shaped general-purpose mechanisms, developed to solve problems that pertain to all ecological niches and are common to all species, for instance, associative learning mechanisms, whose signature is physiologically identical in all organisms. A recent central tenet in Cognitive Sciences is that a set of basic mechanisms exists that is shared by all species and independent from experience that serves to deal with common physical, social, spatial, and numerical problems (Spelke and Kinzler 2007; Vallortigara 2012). Further skills would be built on these core foundations and would develop later on during ontogeny. Indeed, mental pro¬cesses underwent the same pressure that moulded throughout phylogenetic history all other anatomical characteristics, natural selection. Within this perspective, each species shows intelligent behaviours with respect to its own ability to adapt to specific ecological pressures, and some of these behaviours are comparable even in phylogenetically distant organisms.

Nevertheless, we are still reluctant to believe that all living species are equally evolved, and birds are an example of this mental attitude, as they have long been classified as intellectually inferior to mammals. Such permeating view affected the way scientists looked at avian models so that, for most of the past century, studies on avian behaviour have been limited almost exclusively to pigeons (Columba livia) and devoted to understanding their allegedly marginal learning abilities (e.g., Skinner 1948). The results were not interpreted in terms of mental abilities; rather, they included exclusively mechanical stimulus-response associations, i.e., pigeons could learn to respond to a certain stimulus to obtain the food reinforcement, without a mental representation of the causal relation between their response and obtainment of food (Skinner 1948).

However, during the same historical time window, European ethologists Konrad Lorenz and Niko Tinbergen (later acknowledged with a Nobel Prize for Physiology or Medicine together with von Frisch in 1973) started to witness remarkably complex attachment responses, hierarchies’ formation, and cognitive reasoning in humble barnyard animals as greylag geese (Anser anser). They initiated a process that, in the past 50 years, thanks to rigorous scientific analyses made in the laboratory and in the field, reframed completely the evolutionary framework including the thousands of living avian species. Anatomists accepted that differently organized brains can solve similar problems (for a review: Shimizu 2009), and birds earned a relevant role within the Cognitive Sciences domain, subverting their presumed cognitive inferiority to mammals to the point of being compared to feathered primates (Emery 2006). Despite the difference in telen¬cephalic organisation, both avian and mammalian species have developed a high-level forebrain structure to support complex behaviour.

Birds are now animal models for complex mental abilities, for instance, comprehension of how things work (Kea (Nestor notabilis): Huber and Gajdon 2006), planning for the future (western scrub jay (Aphelocoma californica): Raby et al. 2007), vocal learning (African grey parrot (Psittacus erithacus): Pepperberg 2010; zebra finch (Taeniopygia guttata): Tchernichovski and Marcus 2014), use of optical illusions (Great Bowerbird (Ptilonorhynchus nuchalis): Kelley and Endler 2012), self-awareness in mirror test (magpie (Pica pica): Prior et al. 2008), self-control (Goffin’s cockatoo (Cacatua goffini): Auersperg et al. 2013) and analogical reasoning (crow (Corvus corone): Smirnova et al. 2015).

They are cocky, never chicken out

The chicken (Gallus gallus domesticus), the central focus of this chapter, is a peculiar kind of bird because it neither flies (except for reaching fences of branches) nor sings. It is raised for the production of eggs and meat, and this makes the broad public consider it merely as a factory farming animal. Most people would probably ignore that galliformes (as chickens, turkeys, quails, pheasants, etc.) have a very complex social life and they entertain in sophisticated social behaviors.

Single members alert to an approaching predator to defend conspecifics, putting their life at risk for the benefit of the group. They can even selectively inform whether the danger is travelling via land or via sky, allowing conspecifics to adopt the best defence strategy. If one finds food, it can signal its presence to conspecifics or it can choose to remain silent (Mench and Keeling 2001; Nicol 2004): if the rooster is alone with the food, calls are almost absent; if another male individual is in the surroundings, calls are more frequent (though sometimes are just alarm calls); instead, when in the presence of a female, food-specific calls are sensibly higher in number. These calls are meant to attract the female toward the food source, so that females may feed safely close to males, and males will take advantage of the females’ proximity to mate.

Calls are also modulated on the basis of food quality. A reduced number of calls at low frequencies indicates a kind of food not extremely tasty, thus decreasing the chances that a female would approach the food and hence the male. One could wonder whether roosters are earnest in signalling the quality of the food they find and whether they honestly inform females. An ingenious study by Marler and collaborators (1986) demonstrated that roosters are artful deceivers instead. When the food is not savoury, males emit 50% more calls when they see an unfamiliar female than a familiar one, demonstrating that they intend to inform (or better, to cheat!) the audience to a precise aim. Males compromise their reputation apparently only, because there are minimum costs associated with the adoption of this strategy with unfamiliar hens. Unfamiliar hens will not necessarily be again in contact with them in the future, whereas familiar hens are encountered on a regular basis and deceiving them comes with an extreme cost.

They brood, henpeck, and crow

Chicks learn spontaneously to discriminate what is edible from what is not during the first days immediately after hatching. However, mother hens can signal to their baby chicks the proper source of food by using a distinct call, hence speeding up the chicks’ process of learning and reducing the risk that the chicks may ingest potentially dangerous elements. In an elegant experiment (Nicol and Pope 1996), mother hens were allowed to observe two distinct groups of chicks. One group had access to food of a colour that mother hens had previously learned to associate with palatable food; whilst the other group pecked at the food of a colour associated by mother hens with an unpalatable taste. Hence, chicks of this second group were making a mistake in the mother hens’ perspective. The behaviour displayed by the mother hens turned out to be strikingly different between the two groups: when seeing chicks eating the not edible food, the mother hens responded by emitting calls at a higher intensity, by increasing the number of pecks on the ground and the ground scratching activity. These behaviors were very likely displayed to encourage baby chicks to modify their behavior and hence avoid the risk to ingest noxious food.

Sensitivity to chicks’ errors is one of the criteria defining teaching. When teaching, no immediate advantage follows for the teacher who usually has to modify its own actions in order to facilitate learning in the naïve observers, by keeping online track of their responses (Caro and Hauser 1992). Teaching is rarely conclusively observed in non-human species: cautious scrutiny reveals that apparent teaching events, instead of satisfying all these features, are characterised by the young learning through individual trials and errors after observing the adults, who do not adjust their own behaviour depending on pupils’ necessity. Conversely, hens make a display directed at the chicks (for instance, they peck at grains without eating, but releasing them on the ground so that, by falling, they attract chicks’ attention) and seem susceptible to chicks’ actions because they change their display accordingly. By examples and redirection, mother hens thus guide baby chicks in their first steps in the world.

Later on in life, chicks will need to fight to get access to food resources. A strict dominance hierarchy applies to food access: higher individuals dominate subordinate