A substantial body of work has addressed why animals live in groups. However, few studies have described how group-living vertebrates are able to coordinate their actions and make collective decisions crucial if individuals are to maximise the benefits and minimise the costs of grouping. In this thesis, I apply observational, experimental, and theoretical methods to address this paucity of knowledge, using a social primate - chacma baboons (Papio ursinus) - as a model system. Specifically, I investigate three concepts upon which group-living is reliant: information use, coordinated behaviour and leadership. I address each of these concepts in turn. First in the case of information use, I show that the foraging decisions of individual baboons meet the predictions of 'producer- scrounger games' - evolutionary models developed to predict when a social forager should find its own food patch, or join the discovery of a group-mate. I also use a simple theoretical model to show that social information can allow less well-informed members of large groups to reach a correct decision with the same probability as more well-informed members of small groups. Second, in the case of coordinated behaviour, I show that individual state and the environment (both social and ecological conditions) can influence levels of behavioural synchrony in baboons. Moreover, behavioural synchrony in baboon groups was seen to positively influence the behaviour of another species: rock kestrels (Falco rupicolus) derived foraging opportunities by associating with baboons as they travel-forage together in desert vegetation 'flushing' kestrel prey items. Finally, I examined leadership behaviour. I used an experimental design that allowed me to test between two alternate decision-making modes: despotism (i.e. leadership) and democracy (i.e. a majority rule, voting). Baboon group foraging decisions were consistently led by the individual who acquired the most benefits from those decisions, namely the dominant male. Subordinate group members followed the leader despite considerable costs, and follower behaviour was mediated by social ties to the leader.

Both chicks and adult hens traversed a runway to approach video images of feeding conspecifics, regardless of whether the corresponding soundtrack was played or not. This suggests that visual and auditory components of the stimulus did not exert additive effects and that the visual features of the conspecific videos were the most important in eliciting approach. As in previous runway tests, a familiar screensaver video image was attractive to chicks when they were placed individually in an otherwise novel environment (open field). Furthermore, regular exposure to screensaver videos during the first week of life decreased chicks' fear when they were subsequently placed in an open field with no videos present. These results suggest that chicks remember symbolic video images, that their documented attraction to familiar objects and odours in novel environments generalizes to include video images, and that video stimulation may reduce rear, perhaps by enriching the chicks' environment. Screensaver videos in front of the home cage for 10 min on consecutive days reliably attracted and sustained the interest of individually housed laying hens for as long as 8 days; thereafter interest waned gradually. These results are consistent with those shown by chicks upon repeated exposure to similar screensaver videos. Thus, this phenomenon is not dependent on the stage of development. Furthermore, the hens' interest was fully reinstated when a new screensaver was shown. These results underline the importance of giving chicks the opportunity to investigate novelty. When simultaneously presented with two video images at opposite ends of the home cage, chicks spent more time near bright rather than dull, moving rather than still, coloured rather than black & white, and complex rather than simple stimuli. These findings suggest that chicks have strong preferences for certain features of video images. Collectively these findings clearly demonstrate that chickens readily become attracted to and remember biologically neutral video images.

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Predator-prey modelling involves computationally simulating predator-prey relationships which are observable in nature. Predator species hunt and consume prey species, forming an ecosystem where the population sizes of the various species are interdependent. The models take the form of mathematical equations, where a set of coupled equations model the effect that predator and prey species have upon each other, with the modelling either taking place on a continuous or discrete time basis. Generally to date, the majority of research into the modelling of predator-prey ecosystems has concentrated on a single predator species interacting with a single prey, especially in the case of discrete time implementations. Historically, the modelling of large scale multiple species predator-multiple prey ecosystems would have been too computation ally intensive to be modelled. As computers have increased in power, the execution of these larger ecosystems has become possible. This thesis investigates large discrete time multiple species predator-prey models with the introduction of mutation amongst the various predators and prey species that occupy it. It consists of three main studies. First it was necessary to model and discuss a discrete time multiple species predator-prey model without mutation. This was achieved by the modification and execution of a discrete time single predator- single prey model taken from current literature. A focus here is placed on the number of surviving species when executing the multiple species model for a varying numbers of initial predators and prey species (between 2 and 10,000 species), and the effect of the control parameters varying upon them. Two main studies are undertaken. Firstly the unimodal discrete time map that governs the prey dynamics is varied, with this it was shown that the choice of unimodal map has a great effect on the survival of the predator and prey species. Secondly a study into the effect of predation strategies, which define how the predator hunts the prey species, is presented. Each strategy is outlined and conclusions are drawn comparing each strategy, assessing how effective each of them are in allowing predator and prey species survival in the model. The next step was to detail how mutation could be introduced into the ecosystem, with a Coupled Map Lattice (CML) approach being identified. The second study details the dynamics of this CML without predation. A focus was placed upon a CML where the parameters are linearly scaled across the set of maps. The number of maps in the CML is varied between 10 and 10,000, Comments are made upon how changing the mutation rate affected the dynamics of the CML and conclusions are drawn upon how the number of maps within the CML impacts upon these dynamics. Finally the Finally the two studies are merged, attaining and presenting a multiple species discrete time predator-prey model with CML based mutations amongst the various species that occupy the ecosystem. Again various unimodal maps are usedfor the underlying dynamics of the prey species, and different predation strategies are utilised. The system is first observed in a simple form, with a single predator and multiple mutating preys, and then in more complex form , with both mUltiple mutating predators and multiple mutating prey. Conclusions are drawn on how varying the parameters govern the underlying behaviour and survival of the species within the various models. It is observed, that in such a complex system, with both multiple mutating predators and multiple mutating preys, a large range of non-linear dynamics are possible.

Ethology (the comparative study of behaviour) was officially sanctioned when the zoologists Konrad Lorenz, Nikolaas Tinbergen and Karl von Frisch were awarded the Nobel Prize in 1973. Historians of ethology then mostly embraced Lorenz's definition of the field and did not question the strategy he resorted to when he championed his ethology against other traditions in the study of animal behaviour. Among them, the French studies loomed large, and one main aim of this dissertation has been to make up for their neglect within the historiography of science. This thesis explores the kinds of intellectual, social, cultural and ideological resources French scholars drew upon in attempting to make sense of animal and human behaviour. It maps out the development of animal behaviour studies in relation to psychology and sociology, two disciplines that emerged in the late nineteenth century. First, I examine how zoologists and psychologists struggled for a monopoly over animal behaviour studies. I argue that Henri Pieron instrumentalised animal behaviour studies as a vehicle towards establishing psychology as a legitimate scientific discipline. Second, I explore the late nineteenth and early twentieth century French debate over sociobiology. I examine the argument between the Durkheimian school, who challenged the continuity between animal and human societies and the philosopher Alfred Espinas and many French naturalists, who took this continuity for granted. Finally, I explore how sociobiology re-emerged in the inter-war period, both against Durkheim and Espinas'sociology. Another major theme of this thesis is the different uses of animals (especially Insects and apes) within theoretical discussions in natural history and biology in the late nineteenth and early twentieth centuries. The thesis situates animal behaviour studies within the evolutionary debate and the debate over the transformation of biology, which articulated the tensions between laboratory and field approaches. It also delineates the wider socio-cultural contexts within which insects and apes were employed. The social insects (ants, bees, wasps), in particular, provided scientists and social commentators with analogues to governing principles of the French Third Republic. Studies of maternal instinct mirrored different representations of female identity, and women's roles within society, challenged by late nineteenth century French feminism. Also, comparative studies on ape and child intelligence reflected larger debates about education. Histories of animal behaviour have tended to concentrate on major discoveries and institutional achievements, or on the cultural relevance of such studies. My aim in this thesis has been to bring those two types of history together for the specific case of French animal behaviour studies - to begin to explore how socio-cultural assumptions and material facts informed the French work as well as to examine how studies of animal behaviour were expected to fit into a professional scientific career, even in the absence of a unified discipline of ethology

In this thesis the ideas of network analysis are applied to systems of group living animals. A method of constructing a network of associations by combining group memberships is presented. Methods of filtering the network according to association strength are discussed. . The detection and understanding of community structure within animal social networks forms an important part of this thesis. By allowing the researcher to study (and verify the statistical significance of) intermediate scale structure in the network an insight into the biological processes which may motivate the structure can be obtained. The various methods which have been proposed to detect community structure in networks are reviewed. The use of simulated annealing to detect the structure is discussed. This technique offers the greatest sensitivity in detecting communities, making it very suitable for the detection of the subtle structures that may exist in the constructed network. Two case studies of group living animals are considered: a population of wild guppies and a population of Galapagos Sea lions. In both systems statistically significant community structure is found. The biological processes underlying the observed structure are discussed. In the latter part of this thesis some methods of constructing model networks with realistic community structure are discussed. Inspired by the biological aspects of the earlier part of the thesis; these offer methods of building networks in which the size, strength, and number of communities can be controlled by the researcher.

The aim of this PhD thesis was to investigate the role of arousal during decision-making in chickens. Arousal can occur at various stages of the decision-making process and can have different functions depending on the stage and nature of the decision. A T-Maze methodology was developed for measuring behavioural and physiological indicators of arousal in chickens during a simple decision-making task. Measures of arousal were detectable during a goal viewing period and were differentiated by choice outcome. There was some evidence to suggest that arousal preceded and influenced decision-making, which provided a foundation for investigating arousal during more complex tasks. In two subsequent experiments indicators of arousal were measured when chickens made decisions that varied in their complexity i.e. decisions that were finely balanced and decisions involving the risk of an aversive stimulus. Arousal was not influenced by these aspects of complexity when chickens viewed their options, but did increase in anticipation of the decision outcome that was associated with the risk of an aversive stimulus. Interestingly, there was no evidence to suggest that arousal served to "warn" individuals against subsequently choosing the risky option, as has been suggested in human gambling tasks (using somatic markers). The role of arousal during the formation of expectations was also investigated in two reward alteration experiments. Arousal was gradually adjusted when chickens' expected rewards were unexpectedly altered. This suggests that chickens respond to a reward alteration following the Thorndikian law of effect, rather than by showing successive negative contrast effects. The methods developed and results obtained, provide a platform for investigating arousal during various stages of decision- making, including the role of somatic markers in guiding decision-making in non-human animals.

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