The mechanisms and functions of shark grouping behaviour have received relatively little scientific attention to date. The current widespread use of social network analysis to study animal groups, in concert with rapid advances in animal tracking technology, now allows us to test specific hypotheses about how and why sharks form groups. This thesis uses replicated laboratory experiments to investigate some of the mechanisms underpinning aggregation in a model species of benthic, oviporous elasmobranch, the small spotted catshark (Scyliorhinus canicula L. 1758; Scyliorhinidae). Acoustic tracking of this species in the wild is also conducted to explore how network analyses can be adopted to study the localized movements, habitat connectivity and ranging behaviour of adult sharks. Groups of juvenile S. canicula were characterized by non-random social preferences, crucially, only when individuals were familiar with one another suggesting social recognition is important in young sharks of this species. Genetic analyses of parent and offspring DNA revealed very high levels of multiple paternity in this species, likely due to male sexual harassment and multiple mating, which leads to increased genetic diversity between juvenile sharks. Perhaps unsurprisingly, there was no evidence of kin relatedness structuring social interactions between conspecifics. Furthermore, testing the effects of environment on social behaviour provided evidence that these juveniles aggregated more in structurally complex environments than simple ones. However, at the individual level sharks showed consistency in their social network positions through time and across different habitat types. This result is indicative of personality traits in S. canicula. Using data gathered via passive acoustic telemetry of wild shark behaviour, network analysis provided a useful tool with which to quantify movement between receivers. One chapter has been dedicated to the application of these methods, highlighting a number of different analyses for predicting movement behaviour from such data. Finally, these methods were adopted to address ecological questions in this sexually segregated species. Persistent site fidelity to a localised inshore area by both male and female sharks suggested that segregation occurred at a relatively small spatial and temporal scale. Despite strong evidence of segregation, analyses of movement networks and individual co-occurrences revealed distinct periods of behavioural synchronicity during the months of March, April and May. In addition, habitat complexity appeared to be a significant driver of female behavioural strategy. Enhancing our knowledge of the social and environmental drivers of aggregation and movement in sharks is of great importance given the ecological threat facing many of our ocean’s top elasmobranch predators.

Seabirds are vulnerable to a wide range of impacts at sea and function as important indicators of ocean health. A detailed understanding of their movements and distributions at sea, as well as the types of behaviour in which they engage and the extent to which those activities make them vulnerable to different impacts is critical in effective conservation planning. But their elusive lifestyles and mobility have hampered studies of their at-sea behaviour. Using miniature data loggers deployed on Manx shearwaters Puffinus puffinus this thesis explores the movements, distribution and behaviour of a small-medium pelagic, procellariiform seabird during foraging trips at sea. Foraging distributions were most variable during the pre-laying period when females departed the colony to build their egg. Females foraged close to the colony when local resources were adequate, but more typically foraged in distant shelf edge waters. Males returned frequently to the colony during this period and typically foraged close by, but also in shelf edge waters when local resources were poor. During incubation and chick-rearing the foraging movements of birds tracked from up to four colonies showed considerable inter-annual variability, but were largely constrained to the Irish and Celtic Seas and the inshore waters of west Scotland. Birds from each of the colonies foraged in waters local to their own colony, but also in more distant locations, including the productive Western Irish Sea and Western Irish Sea Front where birds from multiple colonies co-foraged, presumably at high densities. At-sea behaviour was organized into three principal activities representing: (1) sustained direct flight, (2) sitting on the sea surface, and (3) foraging, comprising tortuous flight interspersed with periods of immersion and diving in pursuit of prey. Foraging was highly constrained to daylight hours during which birds engaged in bouts of diving separated by periods of flight or rest on the surface. Most dives were up to 6 m deep, lasting up to 13 s, but some much deeper dives (maximum 55.5 m) were also made. During chick-rearing the use of short and long duration trips may allow parents to control provisioning effort and their own body condition. However, reducing parents’ requirement to provision their chick (by supplemental chick feeding) did not appear to alter the at-sea movements and behaviour of parents, suggesting that at-sea behaviour probably is controlled more by foraging conditions and prey distributions than by the nutritional demands of the chick.

The understanding of the motion of animal groups, such as birds, fish and insects, has been greatly advanced by applying principles of self-organisation – the emergence of global patterns from simple, local, interactions between individuals. The desert locust, Schistocerca gregaria, provides a useful model system for the experimental study of collective behaviour. During plague years, the desert locust can form aggregations extending over hundreds of km. Before developing wings, juvenile locusts form marching ‘bands’ which can maintain group cohesion as they migrate over large distances. In this thesis I investigate locust aggregation, group motion and individual interactions. I also apply the same principles to a study of human behaviour. In Chapter 2, I describe the automated tracking methods that I developed and used to collect the data for the rest of the thesis. In the experiments described in Chapter 3, the relative strengths of the attraction to conspecifics and environmental heterogeneities were explored by presenting groups of locusts with two aggregation sites. I found that locusts had a preference to enter the site with the higher population. The locusts formed dynamic aggregations on the sites; no site was consistently more populated than the other, but individuals were significantly more attracted to the site with the higher current population. In Chapter 4, I consider the effect of marching experience on locust behaviour. Groups of locusts that had experience of directed marching, followed by a sudden reduction in density, behaved indistinguishably from those that had only experienced the lower density throughout, indicating a lack of hysteresis effects in collective responses to change in local population density. In Chapter 5, I investigate a locust’s response to its nearest neighbour. I quantified a locust’s propensity to start or stop moving according to the relative position, orientation and movement of its nearest neighbour. In Chapter 6 the techniques developed studying the locusts were applied to human groups. The response of people to different sized groups was quantified, replicating an earlier study in New York. The response was weaker in Oxford but had the same characteristics of the previous study, showing an initially linear response which saturated. The spatial distribution of gaze copying was anisotropic, tending to occur behind the group.

MSc, Faculty of Science, University of the Witwatersrand, 1969

<div> <div> <div> <p>Parental care has evolved promote fitness gains. Burying beetles engage in extensive pre- hatching and post-hatching parental care providing several avenues to transmit bacteria to their offspring. One aspect of pre-hatching parental care consists of preserving a small vertebrate carcass via oral and anal secretions, allowing the carcass to be used as a reproductive resource. Post-hatching parental care consists in large part of parental regurgitations of the preserved carcass. We sought to determine if pre-hatching parental care resulted in bacterial transmission from adults to carcasses via anal secretions. We then sought to determine if lab-rearing conditions affected the digestive tract bacterial communities of F1 and F2 generation adults. We finally sought to determine if carcasses and post-hatching parental care in the form of parental regurgitations resulted into bacterial transmission to larvae. Using High-Throughput Illumina MiSeq, we were able to characterize bacterial communities of adult and larval digestive tracts, anal secretions, and unprepared and prepared carcasses. Our results show that bacterial communities of adults are dissimilar from anal secretions and prepared carcasses. We then show that lab-rearing conditions do not significantly alter digestive tract bacterial communities of F1 and F2 generation adults relative to wild caught adults. We proceed to show that larvae receiving parental regurgitations have digestive tract bacterial communities similar to their parents whereas larvae that do not receive parental regurgitations have dissimilar digestive tract bacterial communities from their parents. We further show that bacterial communities of prepared carcasses are dissimilar from all larvae. Our evidence suggests that anal secretions to preserve carcasses for the reproductive bout and have no influence on bacterial transmission to neither carcasses nor larvae. Our evidence also suggests that parental regurgitations influence bacterial transmission to offspring. </p> </div> </div> </div>

There are three social dimensions within a family: parent-parent interactions, parent-offspring interactions, and offspring-offspring interactions. All of these interactions are subject to evolutionary conflict, which occurs whenever interacting individuals have divergent evolutionary interests. Family interactions and family conflict are often influenced by phenotypic and genotypic traits of the parents and the offspring. An important phenotypic trait is body size, which can affect fecundity, mating success, and fighting ability. An important genotypic trait is inbreeding status (i.e., whether an individual is outbred or inbred), which can influence its overall quality or condition. In this thesis, I investigate the independent and interactive effects of inbreeding and parental body size on family interactions in the burying beetle Nicrophorus vespilloides. I first show that the body size of the two parents influences the resolution of sexual conflict over the amount of parental care (Chapter 2) and over the consumption of a shared resource (Chapter 3). Here, the shared resource refers to the carcass from which both the parents and the offspring feed over the course of the breeding attempt. I then show that females that won or lost a fighting contest provide more care to their offspring compared to beetles with no fighting experience (Chapter 4). This indicates that female burying beetles make parental investment decisions based on their experience with a contest (which is independent of body size) rather than the outcome of that contest (which is dependent on body size):. In the second half of my thesis, I examine whether family interactions also influence and are influenced by inbreeding depression (Chapters 5–8). I find that a female's mating preference for an outbred versus an inbred male is conditional on her own inbreeding status: inbred females preferentially mate with outbred males, whereas outbred females are equally likely to mate with an outbred or an inbred male (Chapter 5). Even though sibling competition does not appear to have an effect on the offspring's inbreeding depression (Chapter 6), the presence of the mother during larval development can reduce the severity of inbreeding depression (Chapter 7), and this effect depends on the mother's body size (Chapter 8). In Chapter 9, I discuss the broader implications of these findings for evolutionary biology, ecology, and conservation biology.

In this thesis we investigate a model for biological pattern formation during growth development. The pattern formation phenomenon is described by a reaction-diffusion system on a time-dependent domain. We prove the global existence of solutions to reaction-diffusion systems on time-dependent domains. We extend global existence results for a class of reaction-diffusion systems on fixed domains to the same systems posed on spatially linear isotropically evolving domains. We demonstrate that the analysis is applicable to many systems that commonly arise in the theory of pattern formation. Our results give a mathematical justification to the widespread use of computer simulations of reaction-diffusion systems on evolving domains. We propose a finite element method to approximate the solutions to reaction-diffusion systems on time-dependent domains. We prove optimal convergence rates for the error in the method and we derive a computable error estimator that provides an upper bound for the error in the semidiscrete (space) scheme. We have implemented the method in the C programming language and we verify our theoretical results with benchmark computations. The method is a robust tool for the study of biological pattern formation, as it is applicable to domains with irregular geometries and nonuniform evolution. This versatility is illustrated with extensive computer simulations of reaction-diffusion systems on evolving domains. We observe varied pattern transitions induced by domain evolution, such as stripe to spot transitions, spotsplitting, spot-merging and spot-annihilation. We also illustrate the striking effects of spatially nonuniform domain evolution on the position, orientation and symmetry of patterns generated by reaction-diffusion systems. To improve the efficiency of the method, we have implemented a space-time adaptive algorithm where spatial adaptivity is driven by an error estimator and temporal adaptivity is driven by an error indicator. We illustrate with numerical simulations the dramatic improvements in accuracy and efficiency that are achieved via adaptivity. To demonstrate the applicability and generality of our methodology, we examine the process of parr mark pattern formation during the early development of the Amago trout. By assuming the existence of chemical concentrations residing on the surface of the Amago fish which react and diffuse during surface evolution, we model the pattern formation process with reactiondiffusion systems posed on evolving surfaces. An important generalisation of our study is the experimentally driven modelling of the fish's developing body surface. Our results add weight to the feasibility of reaction-diffusion system models of fish skin patterning, by illustrating that a reaction-diffusion system posed on an evolving surface generates transient patterns consistent with those experimentally observed on the developing Amago trout. Furthermore, we conclude that the surface evolution profile, the surface geometry and the curvature are key factors which play a pivotal role in pattern formation via reaction-diffusion systems.

The maintenance of both the psychological and physiological health of captive animals is a key priority of modern zoos. Recognising that characteristics of the captive environment have the potential to decrease animal welfare, methods for quantifying and assessing welfare have been developed as part of the process for improving animal welfare. Traditionally, observations of animal behaviour and quantifying time budgets in relation to those of the animals’ wild counterparts have been utilised to assess animal welfare. Hormonal assays have also been implemented to quantify the physiological stress response of animals in captivity and identify the extent of stress being experienced. Each of these methods focuses on a different indicator of animal welfare, is quantified in different ways and provides a different perspective on the welfare of the animals. Given the limited time and financial budgets available to zoos and animal carers, identifying the most appropriate method of welfare assessment would be advantageous in helping to secure the best possible health of captive animals and to maximise their value in captivity. This thesis implemented both behavioural observations and hormonal assays to identify the strengths and weaknesses of each methodology, and make recommendations for future research. The study involved a group of four Bornean orangutans (Pongo pygmaeus) housed at Twycross Zoo. Behavioural observations involved continuous group sampling and the development of an ethogram to record a comprehensive account of orangutan activity over the course of a 12 week enrichment programme. Simultaneous to these observations, faecal samples were collected from each orangutan and processed via Enzyme Immunoassay (EIA) to quantify levels of faecal glucocorticoid metabolites (fGCM) in each sample. While recognising the recent developments in ecological analytical methods, the capacity for extending network analysis beyond the application to social networks, and its use as a welfare assessment tool were explored. Behavioural and space-use networks were developed using data from a second study of the orangutans housed at Twycross Zoo. The flexibility of network analysis in visually representing different data types allowed for the intuitive representation of complex behavioural data. Further research investigated the use of network metrics in providing deeper insights into animal behaviour and space use patterns. In addition, bipartite networks were assessed for their potential to detect and show patterns in the relationships between two sets of behavioural data. Each of the methods used had a number of strengths and weaknesses, but importantly each contributed a different perspective in the assessment of behaviour patterns and welfare, suggesting that an integrated approach to behaviour studies utilising several methods would be ideal. Cost and logistic constraints make this unlikely in most cases. However, the thesis ends with a look to the future and the recognition that the current rapid development of technology for use in animal behaviour studies, coupled with equally rapid development of analytical techniques, may help to dramatically increase the amount of information gained from the average animal behaviour study in the future. Such improvements have never been more urgent, with the requirement for understanding animal behaviour in light of current extinction rates within the context of habitat destruction and climate change. It is hoped that this thesis will make a contribution to improving future animal behaviour and welfare studies by providing an assessment of both traditional methods of study as well as demonstrating the use and potential of new ways of applying network analysis within such studies.

The behaviour and ecology of Whooper Swans (Cygnus cygnus) were studied on the wintering grounds in Scotland and the summering grounds in Iceland, with a view to extending our general knowledge of the biology of this little studied species. Comparisons are drawn between feeding behaviour shown in terrestrial, freshwater and marine habitats. In Central Scotland Whooper Swans were found to feed mainly on agricultural land and to actively select stubble fields, where they fed on waste grain, from their arrival in autumn until mid-winter. They then changed to feeding on grass from mid-winter until their departure in the spring. They were found to have adopted an activity pattern similar to that of geese, i. e. they were diurnal and flew each morning and evening between a roost-site and a feeding site. The daily activity cycle of feeding varies between habitats, but the differences are not fully explained by functional requirements. The factors affecting the timing of morning and evening flights are discussed. The length of the feeding day increased with daylength and the level of feeding per hour increased so that more time was spent feeding in the spring than at any time during the winter. Although Whooper Swans were found to compensate to some extent for the shortness of winter days by departing to the roost later relative to sunset, it is suggested that it is in the spring when their energetic requirements are highest; they need to store enough energy for migration and breeding and/or moult. The percentage of birds head-up was found to decline curvi-linearly with increasing flock size while the percentage feeding increased. Since there was no apparent relationship between peck rate and flock size, birds in larger flocks gain from increased food intake. A seasonal change in flock size was noted in Central Scotland with larger flocks occurring more frequently between autumn arrival and mid-winter than from mid-winter to spring departure. Although other factors may be involved as well, it is suggested that the advantages of flocking to Whooper Swans may vary depending on whether the food is patchily distributed (waste grain), or relatively uniformly distributed (grass). Differences in the amount of time allocated to feeding and vigilance were analyzed according to age and breeding status, and seasonal changes are discussed. The breeding success of the Whooper Swan, measured using the percentage of cygnets and the mean brood size, was found to vary greatly from year to year. Measurements of mean brood size in Iceland during summer were found to correspond well with those in Scotland the following winter. A particularly poor breeding season in 1979, a year with a very late spring, was noted both in Iceland and on the wintering grounds in Scotland. Whooper Swans are monogamous and territorial. The female does most of the nest building and all of the incubation, while the male remains on the territory, usually either vigilant or feeding. The range of behaviours exhibited by males and females during the incubation and fledging are described and the time allocated to them is analyzed. Displays between adjacent territory holders are described for the first time. These displays were found to be commoner during the fledging period than during incubation. Females were also observed to take part in defence against intruders and it is suggested that an important role of the Whooper Swan's territory is to provide a safe feeding area for the family after hatching. Behavioural co-operation between mates helped to maintain a high degree of protection for the nest and cygnets. Cygnets maintained closer proximity to each other than to their parents and tended to associate with a single parent; usually the female. As cygnets aged, distances between them and from them to their parents increased and their parents spent more time feeding and less time vigilant. The behaviour of non-breeding birds is also described and it is suggested that non-breeders tend to moult in a separate flock from failed breeders. Moult and migration are also discussed in order to provide as full a picture as possible of the Whooper Swan's

The obligate cooperative nature of African wild dogs (Lycaon pictus), unique among social canids, is thought to be driven by high levels of interspecific competition and intra-guild predation with other large socially-organised predators. Research exploring how wild dogs maintain social bonds through social communication, while avoiding detection from potential competitors, is therefore vital for understanding this species. While olfactory and vocal communications are well represented in the literature concerning L. pictus, these channels of communication pose significant risks to wild dog survival, as they are inherently susceptible to eavesdropping by unintended receivers. In comparison, display communication, which requires visual contact between the signaller and receiver, poses comparatively less risk of attracting the attention of eavesdroppers. In spite of this, few studies have explored the use of display communication in wild dogs, leaving its potential significance in maintaining social bonds within packs unexplored. Using video analysis, I investigate how display communication and subsequent social interaction are affected by several pressures of the captive environment. Captivity did not appear to affect the presence of many social display types also used by free-ranging wild dogs. However, sexual behaviour was absent from the study groups, likely due to the use of contraception and pack sex composition. The effects of pack sex composition (single-sex versus mixed-sex) revealed that while the frequencies and durations of many social behaviours were not affected by sex composition, the distribution of social interactions did differ depending on group structure. Here, a highly related, single-sex group was more stable than a highly related, mixed-sex group of the same size. Differences in the captive management strategies, specifically enclosure size and feeding regime, of the two packs, may explain the behavioural differences observed. The death of a pack member permitted investigation of the effects of death on social interactions. While many of the social interactions were unaffected by the death, behaviours relating to the formation and maintenance of social dominance and social hierarchy increased after the dog’s death. The distribution of social interactions was non-random, suggesting that individuals were reorganising the social structure of the pack during this period. Finally, a small study into the effects of simultaneously added enrichments in the pack (post death) revealed that enrichment reduced the frequencies of dominance behaviours and allowed for a more even distribution of social interaction within the pack. This demonstrates how enrichment may potentially be used to reduce aggression within captive animals. Overall, this research reveals that display-based communication is important for the maintenance of sociality in captive African wild dogs. To better understand this endangered species, future studies in free-ranging populations should include this channel of communication.