Vocal mimicry is well documented in songbirds, yet the function of this behaviour is poorly understood. I studied vocal mimicry in a wild population of male spotted bowerbirds Ptilonorhynchus maculatus to determine whether there was any support for the proposed functional hypotheses invoked to explain this behaviour. I collected observational data to determine what species male bowerbirds mimicked and how their mimetic repertoires related to the acoustic environment. Spotted bowerbirds preferentially mimicked the vocalisations of aggressive species, which is consistent with mimicry acting to deter predators or competitors (Batesian mimicry). However, these sounds were also relatively simple in terms of their structure, and may be mimicked purely due to their simplicity and similarity to the species-specific hiss. A survey of mimetic repertoires at three geographically isolated populations revealed a similar pattern in model choice: mimetic repertoires were predominantly composed of aggressive and predatory species but these sounds were also structurally simple. To test whether mimicry was used in a Batesian context I determined what contexts mimicry was produced in. Consistent with predictions, I found that males did not increase their mimetic rate in the presence of conspecifics but did increase their mimetic rate in response to human activity around the bower. To determine how mimetic sounds are acquired in this species, I compared the mimetic repertoires of individuals within a population and found that males with bowers closer together mimicked more of the same species than did males with bowers that were further apart. Closer inspection of two of these mimicked sounds revealed that neighbouring males did not produce structurally similar mimicry,which suggests that mimetic sounds are learned directly from the species being mimicked. Males did not increase their rate of species-specific vocalisation when mimetic rate increased, so these vocalisations are unlikely to serve the same function. Males increased their rate of species-specific hissing when in the presence of conspecifics and this vocalisation is likely to function in intraspecific communication. Males also produced ‘advertisement’ calls when alone at the bower that are likely to attract females to the bower or deter rival males. These vocalisations are a long distance signal that varied in structure in three populations of bowerbird. I discuss potential explanations for geographic variation in the structure of bowerbird vocalisations. Vocalisations may be part of the multi-component sexual signal produced by bowerbirds, but I found no relationship between any aspect of male vocalisation and predicted mating success, so these vocalisations are unlikely to indicate male quality to potential mates or rival males. In conclusion, it seems most likely that mimicry in this species is used to deter predators or competitors, but I cannot exclude the hypothesis that mimetic sounds are learned as a result of their relative simplicity and salience in the acoustic environment. Furthermore, I have shown that mimetic sounds in this species are most likely acquired directly from the species being mimicked. These findings are a useful step towards understanding the function and evolution of this fascinating behaviour.

Cephalopods first appeared around 500 million years ago. Since then they have developed from the external shelled ammonites, belemnites and nautiloid's to the soft bodied organisms we find today. By becoming soft bodied, protection which would have been provided by the shell was lost and a different approach to predator avoidance was adopted. Modern day cephalopods such as octopus, squid and cuttlefish frequently use camouflage techniques to avoid detection. In addition to countershading, which is an often used camouflage technique by aquatic species, the presence of chromatophores allow a versatile and rapid response in relation to stimuli. Cuttlefish expression of these chromatic responses can be categorised into chromatic components. It is the intensity and combination of the expression which makes them an interesting organism to study, when looking at how the environment influences camouflage decisions. In this thesis, I present six experiments looking at how external environmental factors influence camouflage in Sepia officinalis. The first experimental chapter looks at how 3D objects and proximity play a role in not only camouflage, but behavioural responses. The first set of experiments discuss how factors such as contrast and size of an object may elicit different responses both behaviourally and chromatically. The proximity of the cuttlefish to the object was then investigated to determine if visual input was a possible cause for the differences. Size of the object, proximity and contrast produced a differing response to that of a cuttlefish on a uniform background. The two subsequent chapters look at differing light information and whether cuttlefish treat these differences similar to that of low contrast. Reaction to turbid and low light levels show similar responses in camouflage, suggesting that similar mechanisms are employed when there is reduced light and high scatter information. In respect to luminance versus reflectance, cuttlefish seem to be able to differentiate between a projected and reflected image where they appear to treat projected images like a lower contrast value. The last experimental chapter investigates motion camouflage in respect to predation. Prey and distance had a large effect on behaviour and how camouflage was expressed. Over greater distances behavioural variance reduced. Darkening of the head region and arm waving was also present over a greater distance. Camouflage varied in relation to background with a more uniform background producing reduced expression when moving. Stationary predation therefore elicits a different response than that of motion camouflage in cuttlefish.

Introduction – Insect societies are well known for cooperation. However, there is a high potential for conflict both over resources (intercolonial) and over reproduction (intracolonial). Here I present the key results of my thesis in these two areas. 1. – In our first study we show that T. angustula possesses two types of entrance guards, hovering and standing guards, and that they have different tasks. Standing guards, however, can switch to hovering if needed. 2. – Honey bee, A. m. mellifera, guards recognise allospecific intruders via “different odours” not “harmful intruder odours”. 3. – Following up on project 1 we demonstrated a relatively clear division of labour in guarding of T. angustula where guards either act as standing or hovering guards. This study also adds descriptive data on the natural history at the nest entrances of T. angustula. 4. – In our fourth project we found that worker policing in the honey bee (A. m. mellifera and A. m. carnica) has a low cost because few recognition errors are made, 9.6% and 4.1% of eggs in male and female cells were removed in error, and because these errors are easily rectified. 5. – Virgin queens of M. quadrifasciata were only elected in queenless colonies and generally only shortly after the removal of the resident queen. The virgin queens' behaviour did affect their survival or their life time, respectively. Finally, we described the election process of virgin queens by their colony. Conclusion – Mainly the finding of two different entrance guards in T. angustula generated a series of new questions. In addition, this thesis helped clarifying how social insects recognise each other, it provided the first study that did not measure the benefit but the cost of worker policing, and it shed some light on the bizarre behaviour of queen replacement and execution in Melipona.

This thesis considers mathematical models of the interaction between social and territorial behaviour in animals, mainly by probabilistic methods. Chapter 1 introduces the Resource Dispersion Hypothesis, which suggests that territorial behaviour plus dispersed food resources can explain the existence of social groups, and describes an existing model of the process, due to Carr and Macdonald. In Chapter 2 the model of Carr and Macdonald is analysed, and in Chapter 3 an improved model is suggested and its main properties derived, primarily using renewal theory. Chapters 4 and 5 consider various spatial models for territory formation, and the effect, of spatial factors on social behaviour, using analytic and simulation-based methods. Chapter 6 considers the evolution of social behaviour using both discrete-time deterministic models and branching processes to investigate the viability of different strategies of social behaviour in the presence of dispersed resources.

The kea is the only parrot species in the world to include the true alpine environment as part of their habitat. Survival in these harsh alpine conditions has been hypothesised to be the cause of the generalist behaviour of kea, leading to their heightened explorative behaviour and curiosity. Kea are also widely regarded as being extraordinarily intelligent. It is their intelligence that suggests that kea may possess a sophisticated communication system. I conducted a study exploring the potentially complex vocal repertoire of the kea. My study was conducted with wild population of banded juvenile and fledgling kea in Aoraki/Mount Cook National Park between February 2003 and April 2004. I obtained 449 vocalisations from 16 identified and several unidentified kea. The results of this study confirmed that the vocal repertoire of the kea is exceptionally large for a parrot species, encompassing over 17 vocalisations. This study revealed five vocalisations previously undescribed in the kea repertoire and showed for the first time that vocal repertoire of immature kea may be different to the repertoire of adult kea. Two possible gender specific vocalisations were also revealed. The study of apparent vocal responses revealed that kea appear to be able to identify vocalisation types and respond accordingly using combinations of increasingly complex vocalisations. This is also the first study to take advantage of the similarity between human and parrot vocal systems for the kea, by utilizing powerful human speech analysis software. The results of this analysis allowed the identification of subtle differences in kea vocalisations, including the presence of graded signals, not identifiable by use of spectrogram analysis.

Behavioural innovation, the use of new behaviours or modification of existing ones in novel contexts, has been suggested to aid animals in meeting the demands of new or changing environments. Many researchers have studied intra-specific variation in the propensity for technical innovation (i.e. use of new or modified motor actions) using problem-solving tasks, but have found mixed results concerning the influence of individual and ecological variables. Relatively few researchers have investigated the predictors of consumer innovation (i.e. consumption of novel food). The aim of the work presented within this thesis is to ascertain which characteristics explain intra-specific variation in the propensity for technical and consumer innovation in black-capped chickadees. In chapter 2 I analyze dominance rank, exploratory tendency, and habitat urbanization as predictors of problem-solving performance and persistence. I found, for one of the tasks presented to the birds, that dominants outperform subordinates, particularly among rural individuals. This goes against predictions from the necessity drives innovation hypothesis, but may be explained by differences in experience, as adults were found to outperform juveniles in a follow-up analysis. There was also evidence for a positive relationship between exploratory tendency and lever-pulling performance. The lack of consistency in performance across tasks likely arose from differences in task characteristics. In chapter 3 I analyze the predictors of food neophobia and willingness to consume novel food using the same variables as before, as well as baseline levels of corticosterone. I found that birds responded differently to each novel food type and individuals became less neophobic and more willing to consume novel food items as the study progressed through autumn. Additionally, I found a negative relationship between baseline corticosterone levels and food neophobia, and a positive relationship between corticosterone levels and the propensity for consumer innovation. This finding is in line with the knowledge of higher baseline corticosterone driving foraging behaviour. Overall this work provides further insights into the characteristics that may drive innovation and allow animals to meet novel challenges or take advantage of novel opportunities in their environment.

This thesis examines the relationship between insect life history and behavioural decisions and underlying cellular biochemistry, with particular focus on bethylid parasitoid wasps in the genus Goniozus. This comprises the first major body of work attempting to draw links between the underlying metabolome of an organism and its behaviour. This thesis further optimised the first known example of a combined LC-MS and NMR metabolomic approach capable of analysing extremely low biomass samples (<1 mg), a vital requirement when studying the behaviour of individual organisms. Part 1 of this thesis details the optimisation and validation of this metabolomic approach, whilst also examining the effects of aging on the metabolome of adult Goniozus wasps. Part 2 applies this approach to examine the effects of diet, host species and host aging on Goniozus wasp behaviour and biochemistry. Comparisons of the metabolomes of starved and honey fed wasps indicate that G. legneri is capable of utilising a carbohydrate rich diet as an energy source. Aged honey fed wasps possessed higher levels of large storage lipids, such as tri- and diacylglycerides, than starved wasps of the same age. Metabolomic analysis also detected a legacy effect on the metabolome of G. legneri associated with differences in the species of host each wasp was reared on. A similar legacy effect was confirmed when examining the metabolomes of wasps reared on artificially aged hosts. Whilst Goniozus wasp oviposition behaviour was altered by the species of host presented, no links between changes in a wasp’s metabolome and its resulting contest behaviour were found. Part 3 of this thesis examines the morphological, behavioural and chemical mimicry of another wasp, the hyperparasitoid Gelis agilis. G. agilis demonstrated an enhanced predation avoidance rate compared with control species, similar to that of the black garden ant Lasius niger. Agitation of G. agilis also resulted in the chemical emission of a known ant alarm pheromone.

This study examined the sociality of two phylogenetically closely related otomyine, murid rodent species that display differences in social behaviour in the wild. A fundamental characteristic of sociality in mammals is the ability to recognise conspecifics and discriminate between familiar and unfamiliar animals. In rodents, olfactory cues serve as the main source of such recognition and has been linked to dopaminergic reward centres in the brain, structures and regions responsible for short and long term memory, as well as neural processes involved in reducing stress. The neuropeptide, oxytocin, is produced by hypothalamic cells and can act as a neurotransmitter. Recent work has linked these neural, telencephalic structures (the nucleus accumbens, amygdala and hippocampus) to social recognition and oxytocin. Oxytocinergic receptor density is greater in such regions in social, monogamous or gregarious rodents, whereas it is much less in solitary species. Experimental studies have found mechanistic links between oxytocin function and social recognition and discrimination in laboratory mice and rats. However, no known study has tested social recognition and discrimination in wild-caught, non-typical model species in conjunction with a description of their oxytocinergic neuroanatomy. This justified my study to investigate whether the social-living, gregarious, colonial ice rat, Otomys sloggetti robertsi, show similar oxytocin receptor binding to other social species, and whether it has the ability to recognise conspecifics and discriminate between familiar and unfamiliar animals. Similarly, I investigated and compared these traits in a solitary, phylogenetically closely related species, the vlei rat, Otomys auratus. Neither sexes of both species showed social recognition abilities based on olfactory cues. This was surprising, as social-living ice rats were predicted to display recognition abilities. Interestingly, female vlei rats showed the ability to discriminate between a familiar and novel conspecific. The results suggest that vlei and ice rats exhibit social recognition flexibility, while social discrimination demonstrated by solitary female vlei rats may provide adaptive advantages in the wild. The impaired social recognition and discrimination observed by ice rats may be explained by their temporal flexibility in social behaviour in the wild. Colonial living and social tolerance by ice rats may indicate phenotypical plasticity, or ‘social flexibility’, to harsh ecological constraints. In contrast, the neuroanatomy of vlei and ice rats reflects their wild behaviour. Neural oxytocin receptor binding sites, identified using ligand-binding receptor autoradiography, were more intense in the nucleus accumbens, islands of Calleja, claustrum, indusium griseum, prefrontal cortex, insular cortices, extended amygdala, bed nuclei of the stria terminalis and hypothalamic nuclei of the ice rats, compared to that of the vlei rats. The overall patterns of neural oxytocin receptor (OTR) binding in ice rats are similar to that found in social voles, while that of vlei rats and solitary voles are comparable, particularly the binding intensities observed in the lateral septum. The brains of the vlei rat had OTR binding in the medial habenula and dentate gyrus, which was absent in the ice rat brains. Similarly, OTR binding was only detected in the subfields of hippocampus, intermediodorsal and rhomboid thalamic nuclei in the brain of the ice rats. As predicted from their social behaviour in the wild, the telencephalic OTR binding of the two species reflected their socially disparate behaviour, similar to other studies. Based on the lack of extreme differences in behavioural data, and various similarities in oxytocinergic receptor binding sites in the telencephalic structures, I suggest that a continuum of oxytocinergic effects on social, group-living behaviour of these related species may exist in this otomyine group. The differences in neuropeptidergic circuitry in these two species contributes further to our understanding of evolutionary neuroendocrinology of sociality. / Dissertation (MSc)--University of Pretoria, 2016. / National Research Foundation (NRF) / SARChI Behavioural Ecology / Zoology and Entomology / MSc / Unrestricted

The fruit fly, Drosophila melanogaster is an exceptional model species for understanding both proximate and ultimate causes of variation in behaviour. Here, we have examined two behaviors: foraging and mating. We discuss these research projects in turn. Almost 40 years ago, the classic foraging behaviour polymorphism rover/sitter was first discovered. Recently, evidence has suggested that the polymorphism is maintained by negative frequency-dependent selection at the larval stage. In two separate experiments we failed to replicate negative frequency-dependence in the survival of rover and sitter larvae. However, we empirically demonstrated differences in burrowing behaviour between the rover and sitter morphs which may be a possible mechanism causing the negative frequency-dependent relationship between the morphs. Future replication of negative frequency-dependence is necessary if we are to understand the maintenance of this polymorphism in nature. We examined mating behaviour from the perspective of two mechanisms of sexual selection: female choice and male-male competition. The study of sexual selection requires careful isolation of these mechanisms. Owing to difficulties in experimental design, studies have yet to properly separate and quantify the individual effects of female choice and male-male competition in fruit flies. Here, we designed a novel arena to assess true female choice. We then used this arena to test the effect of male courtship interference on mating outcomes. However, due to an unforeseen amount of male harassment of females in the arena, we withhold any strong conclusions about the effect of male-male interference behaviour. We also attempt to demonstrate the potential for sexual selection on traits associated with interference behaviour in males. / Thesis / Master of Science (MSc)

Habitat saturation, due to high population density, and predation pressure have both demonstrated to influence the formation of some social systems. For example, helper-at-the-nest systems are formed when offspring delay dispersal due to a lack of suitable territory availability or high cost of dispersal. In one cooperative avian species, the pukeko (Porphyrio melanotus melanotus), a previous comparison between high density (North Island) and low density (South Island) populations found that at high density, there were fewer dispersal opportunities due to habitat saturation resulting in increased relatedness amongst group members. Climatic variations between the North Island and the South Island could explain many of the results previously found. The recent decimation of a large pukeko population at a North Island site provided us with a unique opportunity to compare group structure between two populations under similar climatic conditions to determine whether or not individuals bred independently in a low density population. For my thesis I aimed to answer three questions. First, how does population density affect the dispersal of offspring from their natal territory? Second, how does population density affect relatedness of adult group members? Third, how does density affect territory size? In this thesis I was unable to determine whether or not dispersal events were occurring or if there was high or low relatedness amongst group members. Territory sizes were significantly smaller at Tawharanui over Shakespear but they were not significantly correlated with group size. Harrier presence was significantly different between paddocks. / Thesis / Master of Science (MSc) / Ecological constraints have been shown to influence the formation of social groups. The decimation of a population of cooperatively breeding pukeko on the North Island of New Zealand provided us with a unique opportunity to compare two populations under different density conditions. I explored the effect of population density on group composition, parentage, and territory size as a means to understand the costs and benefits of cooperative breeding and joint-nesting. Territory sizes were significantly larger under low density conditions. I was unable to determine whether or not population density influenced offspring dispersal or relatedness amongst group members.